work zone synthesis - federal highway administration · work zone synthesis: tiedown methods ......

U.S.Departmentof Transportation

FederalHighwayAdministration

PublicationNo. FHWA-TS-89-036July1989

Work ZoneSynthesis:Tiedown Methods

Shaped Barriers

For Precast Concr43te Safety

Research, Development, and TechnologyTurner-l=aitiank Highway Researct\ Center

6300 Georgetown PikeMcLean, Virginia 22101-2296

NOTICE

This document is disseminated under the sponsorship of theDepartment of Transportation in the interest of informationexchange. The United States Government assumes no liabilityfor its contents or use thereof.

The contents of this report reflect the views of thecontractors who are responsible for the facts and the accuracyof the data presented herein. The contents do not necessarilyreflect the official views or policy of the Department ofTransportation.

~ reoort does not constitute ~ standard specification, ~regulation.

The United States Government does not endorse products ormanufacturers. Trademarks or manufacturers names appearherein only because they are considered essential to theobject of this document.

Tectiical Reprt Cocwentation Page

1. Reprt No. 2. m-,”t A_ssim No. 3. Reciple”t,s m~lq No.

FHWA-TS-89-036

4. Title a“d Subtitle 5. Rew:t mte July 19189Work Zone TrafficManagement ;SynthesisTiedOwn Methods forPrecastConcrete

6. -r foming Organimtion Me

SafetyShaped Barriers8. Perfomi”q Orga”ization RePrt No.

7. AutiorSs)ErrolC.Noel,Ziad A. Sabra,Cor~radL.Dudek

9.mrrom 90r9.nIz.ttOnam and~ dress~ontractor:~an~eltons”ltants,Inc. 10”8&73i3i b%;)

Columbia, Maryland 11. ~“t,act or Grant No.Subcontractor:Dudek & Assoc., DTFH61-88-X-00007

Bryan,Texas 13,m of RePrt ,.6 Pe,i~ ~,ti

12. Swaori.g Ne.q Nm and Addrees FinalReportFederal Highway Administration May 1988 -May 1989Turner-FairbankHighway ResearchCenter6300Georgetwon Pike 14.Spn”ori”g We”q cae

Vir~1n,2771nl-7?q615. SuWl_ntiry Nob.

FHWA ContractManager: GuentherLerch,HRT-20

16. &tract

This report is a synthesisof research findinj;sand current practicesregardingthedesignand applicationof systemsforanchoring(tieingdown)portableconcretesafetyshaped barriers(CSSBS)to highway pavements. Thepresentedinformationisbascclon a literaturereview,fieldobservationanddiscussionswith highway officialsin a selcctio:aof states. The reportpresentsdesign graphicson a number of methods for coritrollingsliding,tiltingand overturningof portableCSSBS, identifiesa]reasfor research,and makes recommendationregardingpracticesand informationthatshouldbeincludedintheAASHTO RoadsideDesign-.

17. Key Words

1

1S. Distrib”tio” Stat-”t

~~ ,

barriertiedown,barrieranchor:sge No restrictions.This document isconcretebarrier,work zone availableto the publicthrough thesafety NationalTechnicalInformation

Service,Springfield,‘VA 22161_—19. S-rity C1as6if. (of khia reprt) 20. ~, ity Classif. (of this ~ge) 21. m. of Pages 22. Prim

Unclassified 1 Unclassified 67 1

i

TABLE OF CONTENTS

1. INTRODUCTION .....................................

II. RESE~CH FINDINGS ON PORTABLE CSSB ...............

III. CURRENT PRACTICES ................................A. Need for Vertical Anchorage ..................B. Application and Design of Anchorage Systems

in Selected States ...........................

IV. ASSESSMENT OF RESE~CH AND PRACTICES .............

v. CONCLUSIONS ......................................

VI. RECO~ENDATIONS ..................................

LIST OF REFERENCES .....................................

APPENDIX ...............................................

Page

1

6

1818

18

45

48

49

50

52

ii

Figure 1.Figure 2.

Figure 3.Figure 4.

Figure 5.Figure 6.Figure 7.

Figure 8.Figure 9.Figure 10.Figure 11.

Figure 12.

Figure 13.

Figure 14.Figure 15.

Figure 16.

Figure 17.

Figure 18.


Figure 21.

Figure 22.

Figure 23.


Figure 26.

Figure 27.

Portable concrete safety shaped barrier .....General categories of connectc)rs forportable safety concrete barriers ...........Hybrid connector system .....................Use of slip plates to reduce lateraldisplacement ................................New YOrk’s H-Pin connector ..................New York pin amd dowel verticall anchorage ...Tongue and groc)ve and side plate testconnector system ............................Texas T-1ock connector design ...............Anchor plates, studs and bolts, ..............Driven anchor plates ........................Barrier anchorage deteminatic)n procedureof Ohio .....................................Anchors rewired per 10-foot harrier segmentfor Ohio’s modified-existing k)arrierchains ......................................Anchors required per 10-foot barrier segmentfor Ohio’s proposed barrier ckkains ..........Impact severity versus roadway width, ........Placement versu[s impact severity ofunanchored barrier chains composed of lo-footlong segments ...............................Partial details of Ohio’s proposed anchorageof portable CSSBS on bridge decks ...........Ohio’s proposed design for pin and loopconnectors ..................................Anchorage with dowel bolt, nut., andwasher ......................................Protecting workers with anchored barriers ...Maryland’s met~~od for anchorir~g portableCSSBS .......................................-cation of anchoring system on Maryland’sportable CSSB ...............................Connector details Eor Marylanti[’s verticalanchoring system ............................Installed vertical anchoring system inMaryland ....................................Virignia’s use of anchor bolts ..............Characteristics of CSSB anchorage inCalifornia ..................................Partial detail of New York’s system foranchoring porta[ble CSSBS ....................Barriers anchored with dowel pins in,Illinois ....................................

Page

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79

10

12131516

22

23

2425

26

27

28

2930

32

33

34

3536

38

39

41

iii

Figure 28. Placement of anchor bolts on New JerseytsType-1 barrier .............................. 42

Figure 29. Design of New Jersey’s barrier anchoringsystem ...................................... 43

Figure 30. Partial detail of Florida’s verticalanchorage for portable CSSBS ................ 44

LIST OF TABLES

Table 1. Results of impact tests on barrier anchorage ... 17Table 2. Connectors and displacement control methods .... 19Table 3. Connectors and displacement control methods

(Table 2. continued) ........................... 20

iV

I,. INTRODUCTION!

The information presented in this report is based on aliterature review, field observations, and discussions withhighway officials in Pennsylvania, Virginia, Maryland,Illinois, New York, California, and Wasl~ington, D.C. , and onmaterial provided by higlxway officials :from New Jersey,Florida, and Ohio.

The concept of using conzrete barriers to restrain errantvehicles from penetratineq the median anf~ to redirect them whileminimizing damage to vehicles and occupants was initiated inLouisiana in 1942. California implemented concrete barriers in1946 as permanent median installations (L]. The basic designof the portable concrete safety shaped l~arriers (CSSBS) usedtoday is the result of Khose experiences in Louisiana andCalifornia and the quest of New Jersey lhighwa!{ officials for amedian barrier with optimum performance characteristics. The~ame V*New Jersey barrier” is associated with the earlyexperimental work on median CSSBS conduzted b~f the New JerseyDepartment of Transportation. The dimensional characteristicsof the New Jersey portable CSSB, shown in Figure 1, have ;oeenadopted by most States. It is 32 inches high and has a two-foot base and a six-inch top. Its lowe:r and upper faces aresloped at 55 degrees and 84 degrees r@s:pectively from thehorizontal plane. The curb edge is about three-inches hig:h.

Early applications of portable CSSBS in work zones involved 15to 30-foot segments without connectors and anchorage. Theirlengths were guided by the need for commercial sizes and ‘theimportance of their mass in restricting movement when impacted.Today, barriers range in length from 3 ‘to 30 :Eeet, have lineardensities ranging from 450–550 pounds per foojz, and areroutinely interconnected in field installations. Increasingly,portable CSSBS are being used to keep vehicle and pedestriantraffic from entering work areas; this :protecjLsworkers,separates two-way traffic, and protects construction equipmentat highway work sites.

From the mid–1970s to mid-1980s several crash testingexperiments were conducted by the California Department ofTransportation (U, ~), the Texas Tran:sportajkion Institute (4,5—, ~) , and the Southwest Research Institute (2, q) to evaluatethe physical characteristics of different portable unanchoredCSSBS , their effectiveness in redirecting vehicles andminimizing occupant injuries, and the behavior of theirconnector systems. During this period, a numlzer of barrier andconnector systems evolved as highway officials became awarethat barriers could gain increased stability in shear, torsion,tension, and moment by using interconnecting devices. Ivey (~)in 1980, commenting on the state of portable concrete barrier

1

n:,=n feetn = n inches

Figure 1.Portableconcrete safetyshaped barrier

2

(PCB) designs, stated: Ilthere are at lezlst as many variat~Lons

in PCB design as there are states in which it is used.q’ Grahamet al. (Q) observed in 1987 that there were more than 24connector designs for portable CSSBS. Tbe April 1988 iSSUe ofthe ITE Journal (9) grouped COnnectOrs irlto six: cate90ries~(a) pin and loop, (b) tongue-and-groove, (c) plate insert, (d)channel splice, (e) double dowel, and (f) I-be?\m. Schematicsof these groups are presented in Figure 2. Each connectorgroup has advantages and disadvantages which are discussedlater in this report under the title of Research Findings OnPortable CCSBS. AS ObserTTed bY Graham, et al. (Q), severalsubclassifications and hybrid systems ha>re resulted fromcombining the design characteristics Of two or more catego]cies.Figure 3 illustrates one hybrid connector which integrates thefeatures of the tongue–and-groove, channel splj.ce, and doubledowel designs. Those interested in deta;Lls pertaining to thediversity of barrier connectors used for research and inpractice are encouraged to review references Nos. 8, 9, and 10.The following section presents research ~Eindings on certainconnectors; it examines their performance and j.ndicatescircumstances when additional stability by vertical anchoragemay be warranted.

/

Pin and Loop Tongue–and--Groove I’lateInsert

Channel Splice Double Dowel I–Beam

Source:(~ )

Figure 2. General categories of connectors for portable safety shaped

concrete barriers

11 II IIII (1 II 11II II 11 II, lr ,,

> II II= :3

11 1!11 !1 =====, ,,, <>II II II 1[11 II 111! ,1 !1 II1[ II 11 II

,,

—

—

T~ical Panel titi a Viewof ConnectionDetail!

rx

E----.....--------,

00 @@

T~icalView

Lx

Panel Elevationtith aof Connection Detail

Sowce (m )

—

—

1“‘

4 boltsand pins

5:&t—42”+Channel Spfice

t

&6“

1“Diameter

12”’ T@ 24” bolt

—L@

G’::,; ‘4

View X–X

Figure 3. Hybrid comector Systeml

5

II. RESEARCH FINDINGS ON PORTABLE CSSB

Between 1972 and 1985, the State of California, and the Stateof New York, the Southwest Research Institute, and the TexasTransportation Institute conducted a number of tests onportable CSSBS. None of these tests were specifically intendedfor the evaluation or establishment of design standards forvertical anchoring systems which attach portable CSSBS toroadway pavements or pavement attachments for restrictinglateral movement. However, the behavior of portable CSSBS andvehicles during some of those tests has triggered concernsabout the need for vertical anchoring systems to supplementhorizontal connector systems. As used here, anchorage refersto the use of devices for fastening the portable CSSB to thepavement or ground and/or devices that can be attached to theground or pavement to restrict lateral displacement. Numeroustopical reports were reviewed for their insights on verticalanchorage.

In 1976, the California Department of Transportation conductedfull–scale impact tests (u) on two freestanding segments ofportable CSSBS of 12.5 and 20 feet with pinned end connectors.The barrier sections were 150 feet long and were impacted withfull-size cars weighing about 4800 lbs and traveling at speedsbetween 39 and 65 m.p.h. The impact angles ranged from 7 to 25degrees. In two of the four tests, the barriers movedlaterally. In one test, where the angle of impact was 40degrees and vehicle speed was 65.5 m.p.h., the barrier rotatedexcessively causing vehicle vaulting. In one low-speed (25m.p.h.) impact at 25 degrees, barrier lateral translation of8.5 feet was observed. Tests conducted by the SouthwestResearch Institute (3) in 1976 alsO indicated thesusceptibility of unanchored portable CSSBS with tongue andgroove and slip plate connectors to shift laterally during 25-degrees impacts by 4500-lb vehicles. Subsequent researchconducted by the California Department of Transportation inlg77 (~) concluded that there may be situations Or Siteconditions where horizontal connectors should be supplementedwith vertical anchorage to restrict lateral translation. Dowelpins for anchoring portable barriers to roadway pavement wereadvanced for consideration. The California Department ofTransportation did not offer any dimensions, material orstrength characteristics of such pins.

In 1977, Lisle and Hargroves (~) studied accidentcharacteristics and driver behavior along installations ofportable CSSBS during the widening of Route 44 in Virginia.The barriers utilized tongue and groove horizontal connectors.On bridges, two 4-inch x 5.4-inch x l-foot steel slip plates(see Figure 4) were anchored in the pavement within the barrierkeyway and were located 2 feet from each end. The slip plates

6

Holes for bolts\

Drainage slot

MortiseIMember

Key

,~g

:{P:: 1.75”x 5“ Ke~ay,“,:::~:;y:

.......,.p..~..~.

V..V.Q:. C 4“ X 5.4”X 12 ~<ey

,;;q;;p;y;Concrete bridge deck ...,..,,,.

,.,.,,.:y.;,;v;.;.y,.,.

X,,”!;’;’’;:: .. ..-.YEF

:Q.:.,:!g.:p.........

.,y.:.:.y{.,,,v ,~.:.p

.;Y;Y<:P:{v<vv:v:,.~:ti;%;++;:_ .,,

l/~ x4.5”Mactine boltDimensions h inches

Figure 4. Use of slipplatesto reduce lateraldisplacement

7

were intended to prevent lateral movement of the portableCSSBS . Of the ten accidents which occurred during the study,five vehicles infringed on or crossed the adjacent lanes andfive remained in the lane next to the barrier. Two of the tenvehicles were involved in wide angle impacts -- greater than 15degrees -– and rolled over. The authors made no commentsregarding the performance of the slip plates in restraininglateral movement.

In 1978, Hahn and Bryden (~, ~) crash tested two SeCtiOnS Ofthe New York portable CSSB. Individual barriers were 20 feetlong. Barrier connectors were of the H-pin design indicated inFigure 5. Both tests involved large cars weighing 4230-4250lbs. which crashed into the barriers at 25 degree angles atspeeds of 52.8 and 54.8 m.p.h. The length of barrier sectionswere 160 feet. Adjoining barriers in the first test were notvertically anchored nor were the joints grouted. In the secondtest, the barriers were placed in tension to remove jointslack, the upstream end was anchored to the ground with dowelpins -- 1 inch in diameter and 4 feet 8 inches long -- tosimulate the resistance due to an upstream end terminus, andmortar was used to grout the joints, thus adding stiffness tothe barrier section. Hahn and Bryden concluded that the NewYork portable CSSB is an effective positive barrier for impactsup to 60 m.p.h. and angles up to 25 degrees and thatsatisfactory vehicle redirection cannot be assured for impactangles greater than 15 degrees. An important conclusion wasthat the New York portable CSSB design does not requirevertical anchorage to the pavement or the placement of asphaltwedges behind them to provide additional resistance due tosevere impacts. Pulling and grouting limited the lateraldisplacement to 15 inches during the tests conducted by Hahnand Bryden.

In search of a more convenient length of portable CSSB, the NewYork Department of Transportation in 1980 developed and crashtested eight-foot segments which utilized H-pin connectors

(M) . The test sections consisted of 20 segments of eight-footbarriers (160 feet long) placed in a straight line. The firstand last segments were anchored to the pavement with three 1-inch steel rods driven into the pavement through dowel holes inthe barriers. Figure 6 shows the pin and dowel design for thisvertical anchorage. The anchorage of the end segments wasintended to simulate the resistance due to standard endterminals which were not used in the tests. Further, thestability of the vertical anchorage was not underinvestigation. Four full–scale crash tests were conducted with2250 and 4500-pound sedans which impacted the barriers at 60m.p.h. and at angles ranging from 15 to 25 degrees. Two of thetests utilized grouted joints, and one of the remaining twoutilized two smooth-faced 20-foot segments in the impact zone.The authors of the report (~) made the fOllOWing Conclusions:

8

sECHON K–K END ~EW

Reinforcern#?nt 19“not show ,,

1“~.—1

$Q

,,:8“ H

T

]; ~H..............!.............-.Y

2“X1’4y.~:~.~{;~26”..............2.7’

,,,:::............................. ,

10“4“X4”X1/Ytube ‘.:

1...................... c

Ttyp

1/4SECTION K–K SIDE VEW

H–PN ~ PMCE

Sowce: (2 )

Figure 5. New York’sH–pin connector

9

J I23 3/4” 3–kchor Recesses at 2“–0” T

4 23 3/4” ~

124”

J

R 30 3/4”+

/

k’”3/4”4For anchoring inc,oncreteslabs,the

~2

tlp may be omitted.

kSee note A 4ANCHOR ROD

NOTE A

Thelengthoftheanchorrodsshallbe suchthatthef.11.tingmitimnm embedmentlengthsareobtained

(a)Intobridgedecks and portland cement concretepavements o – 5“

(b) Into flexiblepavement1,–6“(c)IntoUpaved area2 - 6“

%en anchorrodsareinplace,theyshallnotprojectaboyetheplane.fthe concretesurfaceofthebarrier.Holesin bridgedecksshallbe 1 I/y 0 matimum and made titha core &illor any otherapprovedrotarydrillingdevicethatdoesnottipatian impactforce,

Souce: State of New York Department of ~ansportatlon.Standard Drating 619–3R3

Rgwe 6. New York pin and dowel verticalanchorage

10

1.

2.

3.

4.

5.

ln 1985,

Portable CSSBS meeting New York’s design standardsand using 8-foot segment lengths pro~.ided comparableperformance with 20-foot segments.

New York’s H-pirl connector sysf:em was effective inrestraining and redirecting 4580-lb vehiclesimpacting the barriers at 60 m.p.h. and 25 degrees,although smooth redirection of impacting vehiclescannot be assured.

Lateral barrier deflections for 8-foot se~ents weresimilar to those of the 20-foot segments, so that thesam@ design defections can be used for any segmentlength between 8 and 20 feet.

Barrier deflections and corner damages were reducedby pulling the joints tight and grouting the lowersix inches of each joint from the front to the rear.

Anchoring intermediate barrier segments to thepavement is not necessary unless ver~T small late]raltranslations are re~ired. Tha grouted barriersexperienced a maximum lateral displacement of 6.75feet.

the Texas Transportation Institute (TTI) reuorted the.,.results of field testing of a number of portable CSSB sections

(4, ~, s, z). The tests utilized the tongue and groove barrierconnector supplemented wi~;h steel plates attached to both sidesat the base of the barrie]? junctions. The barrier design ispresented in Figure 7. Tile barrier installations were 120 feetlong. The barriers were unanchored to the pavement, andsegments were 12 feet. Test vehicles weighing approximately45oO lbs. impacted the baa:riers at 25-de\~ree angles and at 60m.p.h. The results (~) of four crash tests indicated a maximumpermanent deflection of 1,8 feet.

Another series of tests conducted by TTI (g) e>ramined theperformance of barriers when impacted by utility-type vehicles:a single-unit truck, five pickup trucks, and two small vans.The test barrier involved the T-lock deS~Lgn illustrated inFigure 8. Segment lengths were 12 feet, and the installedsections were 120 feet long. The impact speed averaged 60m.p.h., but the angles of impact were re:lativel.y flat varyingbetween 6 and 15 degrees. None of the barrier segments wereanchored to the pavement. Test results indicated a maximumdisplacement of 0.63 foot,. This low dis]?lacement wasattributed to the performance of the T–l(>ck connectors as ~rellas the flat impact angles,, The extent of displacement at a 25–degree impact angle was not examined in the series of tests.

As part of TTI’s barrier safety program, Ivey et al (a)analyzed the strength of various connectors for portable CSSBS.

11

,,7 ‘ Qr ‘j

--,*%,.-,+------- 231,,,L ~......... ........... ......Female_ “ -+r~ ~

~ 16”LMale Panel ‘—Panel

1 3/4”

Side plate3/4” @ X 25” (see detail)

Bolts

E~VATION

1“ @ Holes 7

- lo”—

<F6“

~

n

SECTION A–A

SOuce: ( 11 )

Figure ?. Tongue and groove and sideplatetestconnector system

12

1P 3’”+E~VATOR

STEEL CON~CTOR DET~

=

WICAL PANEL PQ,N

— 31”-

m[

,.,::,,................

‘T

I

.-.::,,. . . . . . . . . . . . . . .;

Formed, tapered box6 1/2” tide-topY tide-bottom4 1/2 deep, 18.5”

}

long

t— 24”+END ~EW

Rgure %. Texas T–Lock connector design

13

Of relevance to vertical anchorage was their discussion on theoccasional unavailability of space for deflection behindportable CSSBS. The authors noted that the lack ofdisplacement space would reguire portable CSSBS to functionlike permanent barriers and suggested that anchoring barriersto their contact surfaces might be appropriate, but theirdesign must be consistent with the expected intensity of thevehicle impact. The authors cautioned against routine use ofrigid ground connectors on portable CSSBS and stated that theneed for very small deflections should be a rare occurrencewhere large vertical drop, high speeds, and large angles ofimpact are anticipated, and the roadwork is expected to lastmore than a month. Ivey et al. made reference to California’smoderate approach which involves vertical anchorage with twoone–inch diameter steel rods driven three feet into the soil orbase at each segment end. The authors conducted simulatedcrash tests on three deflection-control devices attached to 12–foot barriers with tongue-and-groove connectors withoutstabilizing slip plates. The devices were 4-inch x 4-inch x0.5-inch steel angle plates connected to the concrete pavementwith driven studs (see Figure 9) or anchor bolts and 0.25-inchthick triangular steel plates (see Figure 10) driven into thesoil against the base of the barriers. The simulated impactswere performed with a 5000–lb. bougie which impacted thebarrier at 20 m.p.h. and 90 degrees. As indicated in Table 1,in each case barrier segments rotated or the studs and anchorbolts failed.

None of the literature reviewed supports routine use ofvertical anchoring systems. None of the reports presents aclear and convincing case against the need for the verticalanchorage of portable CSSBS when used in long-term work zoneson bridges where displacement space behind the barrier islimited or non-existent. TTI’s test of T-lock connectors whichshowed 0.63 foot of displacement for non-vertically anchoredportable CSSBS were not based on impact angles above 15 degreesand did not use the more popular types of connectors, most ofwhich were not crash-tested. Based on the potential for largedeflections as observed by Ivey, et al. and for situationswhere the extent of barrier displacement must be contained tosome maximum level, vertical anchorage represents an importantsupplementary system.

14

+

t6’t6’tg’+6’”t6’i

4“x4”x.25”steelanglestith driven studs or anchorboltsused to anchor barier to concretepavement.

\ -.

> <

dia.

-3/16” dia.

Driven Stud

SO~rCe: (E)

=

r*

1 1/2” : /8” dia.—

T.v.’..P,v, .’.’T.V,T..’F.Y..,,F,. ..F.V.Y,.

8“ V.’.V..V.’.V.’.Q.’ .V.’.v..v..v

L

,,V:,V..V,. ..V,,V..V,. .,.,V,.,V,.,?,.,V,.,v..v,..V.v, ..V.V.y.y y.y.

— ‘v.’. .’.V.....V,,v..v.,v

DrilledAnchor Bolt

Mgwe 9. hchor plates,studs Ekndbolts

15

~ 1/4” thick triangular plates driven into soil

-~

*M............ ............

~lgure 10. Driven anchor plates

16

Table 1, Results of impact tests 011barrier anchorage- ..=....-.—-.-—...---—.. .. ..--—--- .— —.—

Test kchorage Impact Peak Impact InlpaCt

‘ ‘ -“-’’”””””’”’l”-”””-””””T“”””””””-”

Displacenlent Commentsesignation Design Location Force (kips) Duration of Barrier

(se.) (in)

Barriersegmen

3825–C3 hgles With 3 ft.rightof 41.3 0.050 0ahotrt lo<vered

DrivenStuds jointand ilnpactbut ret

21 in.high upright

—

3825–C4 AnglesWith 3 ft.rightof Studs faiied

DrivenStuds jointand 48.8 0.050 182i in.high

Anglestith 1 ft.rightof

1-------1

Studsfailed3825–C5 DrUed jointand 52.4 0.060 0

hchor Bolts 2! h. high

hgies tith 1 ft.rightofDxiiled

bchor boltfai3825—CS

hchor Bolt

“n&:tigh ‘~ ~---+-:------!----------hgies tith Centeredon

3825–C7 fi~ed 57.9

w

Anchorbolifaijotitand 0,046 72

kchor Bolts 21 in.Mgh

Impactedbarri~imgtiar 2 ft.rightof

3625–C6 Plates 69.5segmentrotate

jeki aad 0.060 0 loveredgeandEl h. Mgh reston itssid,

Source: ( & )

111. CURRENT PRACTICES

A. Need for Vertical Anchoraqe. Crash tests conducted onportable CSSBS over the past 15 years substantiate thepossibility of lateral movement when barriers are impacted byhighway vehicles, but those tests also indicate a high degreeof randomness in the observed deflection, thus making itdifficult for researchers and practitioners to be certain thata specific maximum deflection can be estimate at fieldinstallations. The practitioners~uncertainty about barriermovement has apparently been resolved by judgmental

aPPlicat~O?s of vertical anchoring systems. Six of the eightstates vlslted have adopted at least an informal policy onanchoring portable CSSBS on bridges. Officials inPennsylvania, Virginia, Maryland, l~]inOis, New york, andCalifornia agree that bridge work involving deck, sidewalk, andrail rehabilitation must often be done in situations wherethere is limited space to accommodate portable CSSBS, workmen,equipment, pedestrians, and vehicular traffic. New JerseyrFlorida, and Ohio are also users of vertical anchorage forportable CSSBS. Thus at least nine states have found thatthere are mitigating circumstances where the lateral movementof portable CSSBS must be restricted by supplementary verticalanchorage. As can be seen in Tables 2 and 3, a variety ofhorizontal connectors are used. Thus , the strengthcharacteristics of vertical anchoraging systems will vary. ofthe nine states mentioned above only Ohio has establishedpreliminary detailed guidelines for the application ofanchoring systems. Practices in a selection of states arediscussed below.

B. Application and DeSian of Anchorinq Systems in SelectedStates. Ohio rewires base restraints on portable CSSBSwhenever they are installed on the outside of curves, installednext to open ditches, used as a traffic separator in mediansnarrower than five feet, or used in other locations sensitiveto lateral deflection. This is accomplished by means of anarrow strip of asphalt one–to-two inches high placed next tothe barrier base on the side away from traffic. If traffic ison both sides, restraint is accomplished by fastening twotemporary one-foot sections of steel channels to the pavementso that they fit in the base keyway. If dowel holes areprovided in the barrier, two temporary one-inch dowels areinstalled in the pavement through the dowel holes.

Ohio has a systematic process for determining the verticalanchorage re~irements of portable CSSBS on bridge decks. Thisprocedure is the result of recent research (~) aimed atimproving the design of Ohio~s temporary CSSBS, CSSBconnectors, and anchoring systems. Ohio’s standards forbarrier anchorage, adopted in June 1988 (~) , consider speed

18

Table 2. Connectors and displacement control methods

Supplementary Methods for ControllingStates Barrier Connectors Lateral Displacement

Ohio Bolt and rebar loop. 1-2 inch asphalt strip behind barriersTongue and groove l-foot steel plates attached to pavementPlate insert below barrier. Dowel holes in barrier with

l-inch dianeter through bolts with nuts orwith resi~ embedment 6 inches in c~ncrete=

Spacing of bolts based on clearance, barrierdesign, and vehicle speed.

Pennsylvania Tongue and groove.

a

Maryland Tongue and groove.Plate insert.

Virginia Tongue and groove.Pin and rebar loop.

7/8-inch to l-inch diameter through boltswith nuts. l-inch dianeter bolts in resinembedment at depth 4-6 inches in concrete.Pullout strength of 18,000 psi. Spacing of1.5-2 feet.

1.25-inch diameter through bolts with nutwashers and anchor plates. Minimum bolt,tension of 16,000 lbs. Minimum bolt shear13,000 lbs. Bolt spacing of 6 feet ontraffic side.

4.o x 5.4 x 12-inch slip plates attached toto pavement below barrier. Barrier lengthranges 10-20 feet. Two plates per barrierunit. 1.25 diameter through boltf with nuts,washers and resin embedmerit at m~nimurn depthof 5 inches. Concrete minimum strength of4,000 psi. Bolt pullout strength of 44,200lbs .

Table 3. Correctors and displacehlent control methods (Table 2 continued)

California J?in and rebar loop, Barrj.er length of 20 feet. Anchor bolt inresin embedment at 6 inches minimum. ‘Twobolts per barrier and located at 3.75 feetfrom each end. l-inch diameter drift pinplaced in dowel behind barrier, 5 inches intodeck, 1. foot from barrier end. 1 foot x 1foot berm bel~ind barriers.

I.-inch diameter anchor pins embedded at 5inches in resin in cor~crete, 1 foot 6 inchesi~~ asphalt. and 2 feet 6 inches in unpavedareas. S~~acinq based on barrier length.

New York H-Pin (1-Beam)

Illinois Pin arid rebar loop. l-inch diamt!te~:~:>:i.~~s‘tl~roughdoo~el.ho].es inPin arrd wire rope barriers. 3 pins per l..O-foot barrier

segment. Sty):-ofoan pads beneath barriers.Strength of anchorage [~ni.tsnot available.

Florida Tongue and groove. O.-/inchch anchor bolk arlci&3.ai:esw~lich servePin and rebar loop. as connector anti vertical arlcl].or.One boltPin and ~ebar loop, per ~ointc Pull.otltstrengtillo:t 14,000 lbs.

Separation e~als k>arrier I.engt.llo

New Jersey Tongue and groove. l-inch diameter bolt and rr~rkin embedr[lentTongue and groove with resin. Embedment deptk~ of 7 inches insplice plate. concrete and 13 inches in asphalt minkr,irrme

Pullout strengt:h frc>m c:onc~ete is 20,5000lbs . 2 feet spacing c>n one side. 4 feetspa~;ing on l>oth sides.

(m.p.h.), roadway width (feet), and impact severity (foot-kips)in determining the clearance required between portable CSSBSand the edge of bridge decks. Speed and roadway width are alsoused to determine the number of anchor bolts. Ohio’s barrieranchorage procedure is presented in Figures 11 through 15. Atthe re~est of the Ohio Department of Transportation, the fulltext of Ohio’s procedure is presented in Appendix A in order tominimize misrepresentation. As indicated in Figure 11, Ohiorequires that all temporary barrier segments on bridge decks befastened to the pavement using one–inch diameter, high-strengththrough-bolts or approved resin anchors, and that resin anchorsbe embedded a minimum of six inches in firn concrete. Thepreferred location of the anchors is on the traffic side of thebarriers. Two anchors per barrier segment are the minimumrequirement. The location and design of the dowel holes arepresented in Figure 16. The Ohio standards (~) were based oncrash tests conducted by the California Department ofTransportation on portable CSSBS with pin and loop connectorsin the mid-1970s. Ohio’s pin and loop connector design isindicated in Figure 17. The Ohio report (~) recommended thatthe clearance distance between the edge of the portable CSSBSand the edge of bridge decks should never be less than one footand that unanchored barrier chains, except for impact severityless than 30,000 foot-pounds, must be at least four feet awayfrom the edge of the deck.

Currently, Pennsylvania has no uniform standard (~) on thedowel hole and bolt system used for anchoring portable CSSBS tobridge decks. Vertical anchorage is determined on a case-by-case basis by district engineers. A common practice in somedistricts involves the use of 7/8-inch to l-inch diameter boltscemented with a resin at depths of 4 to 6 inches in bridgedecks to develop a pull-out strength of about 18,000 lbs.According to field officials, this treatment has beensufficient to contain most automobile impacts. However, thecontainment of errant trucks cannot be assured. One officialnoted that on long bridges the repetitive nature of drillingholes in bridge decks and inserting cementing resin and boltscould result in reduced care by workers in insuring that theholes are properly prepared to enable a strong bond between theconcrete, the bolts and the resin. Occasional failures in thebond between the bolts, resin, and concrete and in concrete ofthe pavement or the barrier have been observed. Fieldengineers could not recall any bolt failure due to shear ortension. However, there is increasing concern about theadequacy of vertical anchorage for restraining and redirectingtrucks. Pennsylvania has just initiated research on verticalanchoring systems aimed at evaluating current practices anddeveloping standard specifications. Figure 18 illustrates adowel hole with anchor bolt, nut, and washer at a constructionsite in Philadelphia. The bolts were spaced at approximately18 inches. Figure 19 shows a bridge deck construction projectwhere the barriers were anchored with reuseable bolts insertedin the deck through dowels in the portable barrier. Limited

21

—

BARRIER ANCHORAGE REQUIREMENTS :

THE ANCHORAGE REQUIREMENTS FOR TEMPORARY PRECAST CONCRETEBARRIERS CAN BE DETERMINED BY USING THE FOLLOWING PROCEDURES.

1. ENTER FIGURE 12, WITH THEPOSTED SPEED LIMIT * ANDREQUIRED WHEN THE MODIFIEDUSED.

ORENTER FIGURE 13, WITH THEPOSTED SPEED LIMIT * ANDREQUIRED WHEN THE PROPOSED

KNOWN ROADWAY WIDTH AND THEFIND THE NUMBER OF ANCHORS(EXISTING) BARRIER DESIGN IS

KNOWN ROADUAY UI DTH AND THEFIND THE NUMBER OF ANCHORSBARRIER DESIGN IS USED.

2. IF THE BARRIER INSTALLATION IS TO REMAIN UNANCHORED ,EITHER BECAUSE OF LOW IMPACT SEVERITY OR THEAVAILABILITY OF SPACE BETWEEN THE BARRIER AND THE EDGEOF THE BRIDGE DECK, ENTER FIGURE 14, WITH THE KNOWNROADWAY WIDTH AND THE POSTED SPEED LIMIT * AND FIND THEIMPACT SEVERITY . THEN , WITH THE KNOWN IMPACT SEVERITY,ENTER FIGURE 15, AND FIND THE MINIMUM CLEAR DISTANCEREQUIRED FROM THE EDGE OF THE BRIDGE DECK AT WHICH THEBA~IER (MODIFIED OR PROPOSED) CAN BE LOCATED.

* THE POSTED SPEED LIMIT SHALL BE DEFINED AS THE SPEED THAT ISACTIVELY ENFORCE D EITHER BY LEGAL MEANS OR TRAFFIC CONTROLDEVICES .

ALL BARRIER SEGMENTS SHALL , WHERE REQUIRED, BE FASTENED TOTHE BRIDGE DECK USING ONE INCH DIAMETER HIGH STRENGTH THRU BOLTSOR APPROVED RESIN ANCHORS. WHEN RESIN ANCHORS ARE USED THEY NUSTBE EMBEDDED A MININUM OF 6“ INTO FI~ CONCRETE. GENERALLY , ALLANCHORS SHALL BE PLACED ON THE T~FFIC SIDE OF THE BARRIER UITHTHE ANCHOR PATTERN SYMMETRICAL ABOUT THE CENTER OF EACH TEN FOOTSEGMENT . EVEN THOSE PRECAST CONCRETE BARRIER SEGMENTS NOTOTHERWISE REQUIRING ANCHORING SHALL, WHEN MCATED ON BRIDGE DECKSCROSSING OVER ROADWAYS , RAILROADS , AND/OR RECREATIONAL AREAS, BESECURED BY NO LESS THAN TWO ANCHORS **.

** UNLESS BARRIER SEGMENTS ARE TO BE INSTALLED 6 FT. OR MORE(CLEAR DISTANCE) FROM THE EDGE OF DECK, EQUIPMENT, AND/ORPROBABLE WORK AREAS .

Figure 11. Barrier anchorage determination procedure of Ohio

22

\\

\

\

.

\

@ NO.REQ

\ .

@

j 30 35 40 45

VEHICLE SPEED IN MPH

\@

\

\

@

L,ANCHO RS

?ED

\ \-

55 60

Source: Reference No. 19 (Ohio)

Figure 12. Anchors rewired per 10-foot barrier se~ent forOhio’s modified-existing barrier chains

23

35 l\ I I I \\ ! I ! \, Iw

“~ 25 I I \l I //

I I \l

3 ‘NO. OF ANCHORS

>R-EQt IREo

a3 ~o \naoK @

\

1020 25 30 35 40 45 50 55 60 65

[51 I I [ I I I \<

VEHICLE SPEED IN MPH


Figure 13. Anchors required per 10–foot barrier se~ent forOhio’s proposed barrier chains

24

80,00

70.00

60,00

50,00

40,00

30,00

20.00

10.00

0.001( )0’ 15.00’ 20,00’ 25,00’ 30.00’ 35,00’ 40.004

NOTE :

*,RoADwAy WIDTH IISHALL BE DEFINED AS THE CLEAR DISTANCE BETWEENTHE TRAFFIC FACE OF THE PRECAST TEMPORARY CONCRETE BARRIERCHAIN AND THE PE~ENT BRIDGE RAILING C)R THE FACE OF SIDEWALKOR SAFETY CURB.


Figure 14. Impact severj.ty versus roadway width

5.0

4.5 -

4.0

3.5

2.5

BARRIER C~IN

2.0 —

1

1.5- !

1.0; 10 20 30 ~ 50 $0 70 80 ~~IMPACT SEVERITY IN FT-K)PS


Figure 15. Placement versus impact severity of an unanchoredbarrier chain composed of 10-foot long se~ents

26

2, ?,7. 6, 7,

NOTES

N.. 5 BarsBofi Ways

N1 anchors shall be 1.”diameter, hi~h\ 19- strength, thr” bolts or approved resin

anchors. Men resin anchors are used,

32, they must be embedded a m~mum of

! I6“ into ftim concrete,

Figure 16

k 24*SECTION B–B

Partial detailsofon bridge decks.

Source: Bureau of Bridge Structural

;;zg.:::o:er’:;yt ‘f

Ohio’s proposed anchorage of portable CSSBS

27

—

--!‘miw4

J———T

(( -——

—

+84”pAl

—

I

2“

10”*

——

A

——i

3“

28

(Pennsylvania)

Figure 18. Anchorage with dowel bolt, nut, and washer

(Pennsylvania)

Figure 19. Protecting workers with anchored barriers

30

space for barrier displacement, reduced lane width, and workerprotection were the prina.ry reason for this application ofvertical anchorage.

The State of Maryland has an establishec~ practice of routinelyanchoring portable CSSBS to bridge decks during long-termconstruction work. Only the barrier segments located onbridges are fastened to the pavement with a system of anchoringplates, epoxy-coated open-coil inserts for attaching the platesto the barriers, and 1.25-inch diameter bolts with nuts andwashers for attaching the plate to brid<le decks. Figure 20presents the material specifications and method of verticalanchorage adopted by the state. A minimum working load tensionOf 16,000 lbs. and shear of 13,000 lbs. are specified for thebolts . The epoxy-groutecl bolt system for barrier attachment isrequired to develop a minimum compressive strength of 6,500pounds per square inch in 72 hours. As shown in Maryland’zsstandard drawing (Figure 21), the two anchoring plates used onstandard 12-foot single-faced portable CSSBS are located threefeet from the ends of each segment. Figure 22 presents theconnection details for sj.ngle-faced and double–faced portableCSSBS used in Maryland. It should be noted that theinstallation of the anchoring system rec~ires access to theunder structure of the bridge deck for the plztcement of somewashers and for tightening the longer bolt of each plate.Figure 23 depicts a finished installation. Highway officialsand field engineers could not recall any failure of thevertical anchoring system during traffic accidents and aresatisfied with its performance, although this method ofinstallation has not yet been evaluated by controlled crash’tests.

In Virginia, the need for barrier anchorage is determined byfield engineers on a case-by-case basis. ~o methods ofanchorage are used depending on the extent of lateralresistance needed and the location of barriers. Figure 4,,presented earlier, depicts Virginia’s practice of using 4-inchx 5.4-inch x l-foot steelL slip resisting plates for controllinglateral displacement; these are anchored to the pavement in thekeyway beneath portable CSSBS. This type of anchorage is usedon installations separat!Lng lanes of traffic flowing inopposite directions and on surfaces superelevated at a rategreater than 0.75 inches per foot. It :LS not used on bridgedecks as exterior parapets or railings. Each plate is attachedwith two machine bolts and two washers. Two slip plates areused per barrier segment; the segments range in length from 10to 20 feet. Portable CSSBS which function as exterior parapetsare anchored either with anchor bolts, washers, and nutsembedded in the pavement or with anchor bolts, washers, andnuts applied to holes drilled through b]ridge decks. These twomethods are illustrated in Figure 24. :rhe system usingembedded nuts is required to develop a minimun? pullout strengthof 44,200 lbs. The compression strength of the barrier has aminimum rating of 4,000 pounds per square inch.

31

GENE RAL NOTES

MATERIALSCOncrctc: All concrctc shall meet the rcquircmetns of Mix No.6(4500p.s.i.)

ReinforcingSteel:

structuralSteel:

Anchor Boltx

Coati[lg

All wire fabric shall be 4x4”-W4XW4

All structural steel shall meet the requirements of A.S.T,M A-36 orbet ter.

All anchorboltsshallbc as indicatedon details,If notspccificdthisshallbeA.S.T.M.-A325.

Faceadjacentto roadway and top of precast barrier to be coatedwith two coats of white CXPOXY paint. Cost of coatings to bcincluded in bid price For the barrier, or item which include barrier.

METIIODS ~ ANCHORAGE CONN ECTION ~ ~ ~

-EXISTING BRIDGE DECK TO BE REMOVEDHoles for anchor botts in existing bridge deck shall be drilled. Use 1/4” o boltswith S 1/2” x 3/4” sauarc wnshcr under existing deck slab,as shown. Boltsshallbeof sufficientlengththatwhen nut is tightallthe threadsof tbcnut arc engaged.Provide Type “A” ptain washer SAE N (narrow)foreach 1 1/4”o boltsat connectorplate.

-EXISTING BRIDGE DECK TO REMAINHOICSfor anchor bolts in existing bridge deck shall be cored. Use 1 l/4. o boltswith 5 1/2” x 5 1/2” x 3/4. square washers under existing deck slab, as shown. Boltsshrill be sufficient length that when nut is tight, all the threads of the nut areengaged. Provide Type “A. ptain washer SAE N (narrow) for each I 1/4. o bolt atconnection plate. The Contractor is olerted, that it is the intent, that as littledamage 8s possible will be done to the reinforcing steel in the bridge deck.ThcrcCore, the Contractor shall locate the reinforcing steel and space the bolts tOmiss the reinforcing steel, all as directed by $he Engineer. Fill all cored holeswith epoxy grout after barrier is removed. (See below for grout composition).

-w~=1 J/4” o bolt to be placed in an epoxy coated open coil anchor insert (cast in slab)whose minimum working load tension strength is 16,000 # and shear strength is 13,000#with a minimum lc”gth of 7 lf2”. Coil to be tapped for a 1 1/4 N.C. thread bOlt. NOinsert shatl bc longer than slab depth minus 1“. Provide Type “A” plain washer SAE N(narrow) for each 1 J/4” o bolt at connection plate. Full811insert%withepoxygrout after barricrisrcmoved. (Secbc!ow for grout composition).

- ~ COM POS[TIONAIIy areas of bridge decks, to remain in place, damaged as a result of anchoringtemporary concrete barriers (anchor holes, etc.) shall be repaired to the satisfactionof the Engineer using an epoxy grout. Epoxy grout shall consist of sand and epoxy,mixed by volume according to n]anufacturers recommendations. The epoxy grou$ shall becapable of developinga minimum compressive strength of 6,500 psiin72b~~~~wbe~tested in accordance with MSMT 501.Sand for epoxy grout shall conform to theSpecifications Subsection 903.11

Sourcti Standard No, M (5,09).X3-143 Maryland Department of Transportation

Figure 20. Maryland)s method for anchoring portable CSSBS

32

+;?:gr:L,._6fi:L1:6xL1_6~L,.,.J,, ,! 1:,,::.- :: :: :: *

~ 5“. ......-——— ----.-----———............——-. ........ —-— .......z-

~ ~“< ~--------i \:- ‘

{p-w.......

~w

.; ;------------1:-----------1 :-------,, ““- ,

k1/4”

TrtificSide 3 3/4”

~~SlOt and Liftbchors (~)

PMN

_ Ut hcbors 2 To” Capacity

. ..8.,.”,,,0.. ~. ~0, .UY Otier Acceptable

— % of ~t kchors andC.mectio. Pkt.,. ——

F 5 ~~PY E 5 1 1........... r----------n ............—--------

‘\

I%

COmectiOn Plates 1“ 3’to be Used Qdyon Bridge.

ELEVATION

Source:Standard No. M(509)–83–143Maryland Depafiment of Transportation

1—3 3/4”

Figwe 21. Locationof anchortig system 0]1Maryland,sportableCSSB.

33

AQ 1 1/4. hex. head bolt tith sta~dard washerand 1 5/16-x3” slottedholes ti comectionP1ate .1o”s leneth o? barrier.

EPOXY co.t~d OPEn .oilinsert *apP.dfor N.C. 1 1/4 dia.bolt tin. we.load tension 16,000#Shear Strength 13,000# 1/

~~

?xVx5/16,, x6” welded to Erx8”x5/l& ., created .,,from one plate

51 5/l&xs” slottedhole, hoome.tion Plate,Pemendie”larto face of barrier

1 1/4” Bolt,hex. n“t e“d standard washer

1

i 5/1< da. hole h come etion plate

5 1/Zx5 1/2-.3/4” Sq. washer mti1 5/ 16“ hole for exisUng deok.

CONNECTION

L,Wa_”m 1 1/2” hole diameter

DETAILS

/\

$ ! 1/4” hex. bead b.lt tith stsnderd washer

EPOXY . ..t.d OPCn .oflin,.fi t.PP=dand 1 5/16”x~ slottedholes h comection

1., N,C. 1 1/4 dia.bolt W“. wortig plate aleng length of b-i.,.

load tension 16,000#Shew Stre”gti 13,000$ /

CONNECTION DETAILS

s~andard NO M[~Qg]-g4-1~,Source: Standard No. M 5.09 –83– 143

Maryland Department of Transportation

Figure 22. Connector detailfor Maryland’s verticalanchoring system

34

.’,,e.

F . . . ..”,.

~@

*

.:., .,.

.,. ~~ ‘ ., . ‘;:,:..’.-~. ,.:,-$”’,.’,,.. . . . .. . ‘..:,’,.:”. ,.. ,

. ... ... ... ..... . ... ,.’, .”., .,

>..,, ..., :,,,. .,.,$ * .,,

,.;

:.--’, ------- --------- -

Figure 23. Installed vertical anchoring syste]n in Maryland

~~

C6.1in c

ed193

sufficiently to insure good bond. Mldebris shaU be removed prior totistallation.

DETAIL “A“

C6,in

mP)

DETAIL “B“

Source: VirginiaDepartment of Transportation

Figure 24. Virginia’suse of anchor bolts

36

There is no routine use of anchored portable CSSBS at bridgework sites in California whenever there is a two–foot clearancebetween the base of barriers and any phys~Lcal portion of thework. This two-foot clearance is believed to be sufficient for,barrier deflection if it is struck by a vehicle. Whenever thisclearance cannot be provided, such as along the edge of abridqe deck during widening operations, California requiresportable CSSBS to be fastened to the roadway surface. When thebarriers are placed on curves with radii too severe to makejoints with pin and loop connections, the barriers are backedcontinuously with earth fill. California specifies a maximumqap size between barriers 3.5 inches. Barriers with jointswhich violate the qap size are rewired to have one dowel pininserted in the pavement behind the barrier on both sides ofthe joints; i.e. on the side away from the traffic. The desiqncharacteristics of California’s anchorinq system are presentedin Fiqure 25. The strenqth characteristics of this system wereunavailable. California uses a standard 20–foot lonq double-faced portable CSSB. Dowel holes installed on the barriers arelocated on both sides, 3.75 feet from the ends.

The State of New York rewires the use of vertical anchoragewhen the available space for the deflection of portable CSSBSon bridqes is less than 11 inches. New York officials havereported that their design of horizontal connectors (see Fiqure5) to which tension and grouting are applied has allowed themto control lateral displacement. New York uses several portableCSSBS of different lenqths and has standardized the number ofanchor rods (dowel pins) for each lenqth. Fiqure 26 shows thenumber of anchor rods used for each segment lenqth, the designof the dowel holes, and specifications for anchor rods. Theone-inch diameter anchor pins are alternated on both sides ofseqments and beqin and end 1 foot, 11.75 inches away from eachend. Embedment requirements are 1 foot 6 inches into flexiblepavement, 2 feet 6 inches into unpaved areas, and 6 inches intoconcrete bridqe decks. When needed, anchor pins are placed inevery anchor dowel.

Although Illinois’ desiqn standards allow the use of dowel barsfor anchorinq portable CSSBS to pavements, anchoraqe on bridgedecks is an occasional practice which is determj,ned by districtenqineers. Information on specific conditions which wouldwarrant vertical anchorage was not available. Illinois’ designstandards state that barrier units placed on rigid pavement ormedian surfaces shall rest on styrofoam pads and that unitsplaced on flexible pavement or shoulders shall be secured withdowel bars (pins) of one-inch diameter, be at least 12 incheslong, embedded at least eiqht inches into the base material{and not project above the barrier surface. IlljLnois’ officialsbelieve that placinq portable CSSBS on st!{rofoam pads aids inrecovering much of the friction which could be lost whenbarriers are placed directly on roadway surfaces. Illinoisuses the pin-and-loop connector design and a standard barrierlenqth of ten feet. Six 1.50-inch dowel holes (three on each

37

,,

6 3/4’ .+46 3/4’

zTemporary RailingType K

1 l/4”x6” Slotted Holetot: 4

~

::

.:

.,

. 6“ min

CONCRETE BASE

NoTEs1. For end treatment lay.”t and crash custions, where needed; see Road Plans or Special Provisions2. Paint entire panel white, or cure rnth wtite pi~mented com~o”nd.3. U 3 1/2 gaps to be backed at the basewidth with # 8x19 dowel or 1“ 0 pin each side of the jotit. See Section K-K.4. titernatlve detafis for Yfiing the precast concrete panels of Temporery Railing ~pe K may be submitted by the

contractor for the engineers approval5, &ere barriers are placed on cumes and redii that are too severe to make up joints, barriers are to backed continnouslj

tith earth ffll. See Section H–H6. Attach utits to deck slabs when required by Bridge plans.

i:,i$w.:~ ,,:a/g:.::,\f12min(

Section K-K (*) Section H–H Minimum EdgeDistance

* Section K-K is for P.C. C. pavementalternative detail, 1“5 ptis 2, longtiven ti A.C. or firm soil permitted,mti I,–& deep.

Source: CaliforniaStandard Drating El 1–30

Figure 25. Characteristics of CSSB anchorage in California

1 1/4” # Hole for 1“ flanchor rod (alternate 1sides)

Nominal Length Number ofof Barrier Unit Anchor Pins

20 ft 918 ft E16 ft 714 ft 612 ft10 ft

54

For anchoring in concrete slabs,the tip may be omitted( , , d

I

1“0JANCHOR ROD

L6“ Min

T-

—::

Q: :;::9 ;::,,, 4,,>, ,,, .

;;:::

~~::;i[; {

,,, #!L ~

,,, 4, ,,, ,,

:;

::: 0:: ::,:, \

Stirrups (TYP) ~

4“ X4” x 1/2” tube (TYP) 1

2’

?“

. i:. . . . . . . . . . . . ....}..4=, . . . . . . . . . . . . . . . . . . . . . .

The length of the anchor rods shaU be suchthat the following tinti”m embedment lengths Place mortar b shaded areas when shornare obtained,

(.) Into bridge decks and portlandon the plans, when reqtired by the tableof joint tiaatment, or where directed by

cement ooncrete pavements 0,-5- fie engtieer.

~] ~:: :::::dp:::~Y:~?’-6°men anchor rods are ti place, they shaU notproject above the plane of the concrete sutia.eof the barrier.

Holes in brtdge decks sh-11 be 1 1/2 $ matiumand made tith a core drill or any otherapproved factov driUing device that does notimpart an impact for..

h units that are to be anchored pins shaUbe required h every anchor recess.hchors shall be 1“ @ ASTM A36

Source: New York State, Department of Transportation.Standard Drating 3R3

Figure 26. Partial detail of New York’s system for anchoring portableCSSBS

3Y

side of a barrier unit) are used in vertical anchorage. Onepair of these holes is located in the middle and the remainingpairs are located one foot from the ends of each unit. Thedesign of the holes is similar to that of New York, presentedin Figure 25, except that they are not alternated. Informationon the strength characteristics of the anchoring system was notavailable. Figure 27 shows the arrangement of the dowel pinsused on Illinois’ standard ten-foot barrier units and a pinnedbarrier chain observed on an urban freeway construction projectin Chicago. It was apparent during field inspection thateither some of the pins were not installed to specifications orthat they gradually moved upward due to repeated mild impactsby highway vehicles.

Conditions for using anchored portable CSSBS have not beenexplicitly defined in New Jersey’s design standards. The stateuses the portable CSSB shown in Figures 28 and 29 when it isdetermined that a special effort is reguired to restrict thepotential for lateral movement. Anchor bolts are used in bothPortland cement concrete (PCC) and bituminous concretepavements. One–inch diameter expansion bolts are embedded inthe PCC pavements and are rewired to develop a pull-outcapacity of 20,500 lbs. when embedded at a depth of seveninches in concrete of a compression strength of 3000 pounds pers~are inch. The embedment depth of the anchor bolts used inasphaltic concrete pavements is 13 inches. Information ontheir pull-out strength was not available, but officials putmore reliance on the shear strength of the bolts when they areused in asphaltic pavements. Bolts used in asphaltic concreteare threaded rods made from ASTM A36 steel. Nuts conform toASTM A307. Anchorage must be applied to the traffic side ofbarriers and spaced at two feet, center to center. When boltsare used on both sides, they must be spaced at four feet centerto center.

Florida’s wall tie and anchor plate for portable CSSBS providesfor both horizontal connection and vertical anchorage. Theangle-type plate, shown in Figure 30, connects the barriers inthe manner of side plates. One 0.75-inch diameter anchor bolt,placed in the middle of the base of the plate, is used tofasten it to bridge decks. One plate is used at each joint ofthe section of portable CSSB chain placed on bridge decks. Two27–inch bolts, greater than the width of the base of barriers,are used to attach the plates to the base. Florida’s portableCSSBS also provide for tongue and groove and pin and loopconnectors. Regardless of the type of connectors, verticalanchorage is required for all portable CSSBS when they are usedon bridges. All anchor bolts are reguired to have a pulloutand shear capacity of 14,000 lbs. Wedge or chemical anchor areallowed in lieu of bolt, washer, and nut assemblies. The morecommon application involves assemblies where the anchor boltsare inserted in holes drilled through the deck of bridges. Theminimum length of Florida’s standard barrier is 12 feet, thus,the minimum separation between the anchor bolts is also 12 feet.

40

Figure 27. Barriers anchored with dowel pins in Illinois

4 ‘1

II

4

‘NI

\.m

42

mite concrete classB _

,,Traffic “U Barside 5“ ‘s‘,RSFT 1

1“ R

Steelwasher Al K4“X4”Xl/4”’~TH lr!#

1.

—. . . .~ 2“ (COVER

10“ Rad.

4

— 1“ H 31“

l\l All

‘~ 24,,,,

‘: ‘ .6’$29”q:7:~-+:+:

/1“ @ steel expansion ‘bolt tith a pulloutcapacity of 20,500~S. when embedded7 In 3,000 P.S.I.

1 1 f

*244 ‘CONCRETE PAVEMENT

concrete

TWE– 1 EARRIER

concrete class B _

%

4°FLBITUMINOUS PA~~NT

24”7

TYPE–1 BARRIER

Source: New Jersey Department of Transportation

Flgue 29. Design of New Jersey’s barrier anchoring system

43

SECTION

Anchor b.lts shall ha?e a pufl.ut and shear capacity of :4,000 lbs. Wedge or chemical anchorbolts may be used in lieu of bolts, wasner and ant assembly shown. Co.. driUs shall be usedto constrnct through bolts holes. and, drills speci?ied by Vne manufacturer zhall be “s-d toconstruct exp,anaion and chemical anchor bolt holes. titer removel of walls, anchors shall bOremoved to i’ tin. below deok surlace and hoiba filled w:th epoxy grout.

,x,x,,,@=- fz

WALL TIE ANCHOR

WALL TIE BOLT

Source: Florida Department of Transportation,Design Standard.

Bntton

Roadway

Figure 30. Partial detail of Florida’s vertical anchorage for portable CSSBS

44

IV. ASSESSMENT OF RESEARCE ~D PRACTICES

Interest in anchoring portable CSSBS is based on the need tocontrol lateral displacement, tilting, and overturning whenimpacted by vehicles. Research on horizontal connectors hasrevealed that tilting and overturning can. be partiallycontrolled by strengthening the connectors, inducing tension,and grouting joints. Not all connectors appear suitable forthese treatments. The popular tongue and. groove, and plateinsert connectors, apparently cannot withstand tension, andgrouting their joints apparently defeats the purpose of theirconnector design. Barriers with these connector types needsupplementary methods for controlling tilting and lateraldisplacement. New York’s I-beam connector with tension andgrouting has been determined to be adequate without anchorageonly in situations where the available space for barrierdisplacement is more than 11 inches. California, which usesthe pin and loop connector design, has adopted two feet as theminimum available displacement space for using unanchoredportable CSSBS. Some states mandate anchorage wheneverportable CSSBS are used in long-tern work zones on bridges,regardless of the strength capacities of their barriers andconnectors. The anchorage methods used in practice can begrouped in the following classifications:

1. Throuuh-bolts. nuts ana washers. These are usuallyone-inch diameter steel bolts inserted in dowel holesthrough the barrier and the concrete deck. Insertioncan be made from above or from below the deck.

2. Slip resistant plates attached to deck. These platesoccupy the keyway below the barrier and are used onlyto control sliding; i.e., in situations where tiltingis improbable.

3. Bem behind barrier. Depending on their height andlength, these berms can control both tilting andlateral displacement. Those used in practice areusually less than six inches high and are primarilyfor restricting sliding. Berms are made of asphalt,dirt, or aggregate.

4. Connecting anchor plates. This method involves sideconnecting plates which accommodate at least one boltfor attaching the plate to the pavement at the baseof joints.

5. Anchor Dlate with throuqh-bolts, washers an& nut.This method utilizes a plate which fits the angles atthe base of the barrier and its interface with thepavement (Figure 22). One-through bolt (1 l/4-inch

45

diameter) and nut are used to anchor each plate tothe pavement. Attachment of the plate to the barrieris accomplished with a bolt and resin embedment.

6. Bolts and resin embedment. Bolts are insertedthrough vertical holes in the barrier and are screwedinto grouted anchor nuts embedded in the pavement.

7. Dowel pins. Headless pins, usually made of NO. 8rebar, are inserted through vertical holes in thebarrier and are embedded with resin into thepavement.

8. Pavement pins. These are headless pins which areinserted into dowel holes in the pavement along theside of the barrier not exposed to traffic.

The more popular connectors (pin and loop, tongue and groove,and plate insert) used on portable CSSBS have not been subjectto controlled crash testing to assess the minimum tension andshear capacity for their respective anchoring systems. Thereis limited research on vertical anchorage and the limitedexperimentation that has been conducted (2) clearly indicatesthe potential for large lateral movements at impact and for thefailure of studs or anchor bolts which are less than 0.75inches in diameter, depending upon their spacing. The bulk ofthe crash tests on portable CSSBS did not employ verticalanchorage. However, their results can still be examined todetermine the range of moments that must be accommodated (basedon the type of connectors, impact speed, impact angle, andbarrier lengths) in the design of vertical anchorage. At leastone state, Ohio, has already done this, and Pennsylvania isabout to follow suit.

Officials from the eight states visited recognize the need toanchor portable CSSBS. The diversity in barrier designs,horizontal connectors, and barrier lengths has resulted in an

eWivalent diversitY in anchorage characteristics and types andin the judgment of state officials interviewed. Most of thestates have not experienced a sufficient number of the type ofaccidents which would challenge the limits of their anchoringsystem, and thus, they have no reason to suspect that theirsystem is inadequate. The occasional accident involving aheavy vehicle is viewed as an exceptional case where anchoragemay fail.

It is instructive to note that the 1 to 1.25-inch diameterbolts and pins used for barrier anchorage can provide adeguatetension and shear capacity of 36,000 and 22,000 pounds pers~are inch, respectively. Construction engineers inPennsylvania and Maryland are satisfied with such bolts.However, it must be recognized that all the primary componentsof the entire system -- bolts, nuts, embedment resin, pavement

46

concrete, and barrier concrete -- are potential areas forfailure. Thus a structured approach to the design of ananchoring systerrris necessary in order to ascertain the truenature of a failure. Isolated cases of conical failure of thebarrier and pavement concrete with anchor bolts intact andfailure of the grouting resin have been experienced in onestate. This failure of a barrier system which utilized boltsand nuts indicates that those barriers which rely only onanchor pins are generally less reliable, although it may beargued that the more robust connectors (New York’s I-beam, forexample) could demand lower capacities, in shear and tension,of anchoring components.

Some officials are concerned with the potential for improperinstallation of anchor units on long bridges. Althoughspecifications may prescribe the procedures for preparingdowels for resin anchorage, officials express concern that oncethe bolts are anchored in the resin if~ is impractical to testtheir pullout capacity. The use of through-bolts with nuts andwashers could eliminate some fears about system failure due tofaulty workmanship. However, construction contractors in atleast one state favor less labor intensive methods which do notreguire access below the deck for installing anchor bolts andnuts. Resin anchors applied to portable CSSBS on bridges remaina subject of concern.

Since there is so much variation in the design of barriers,anchorage, and connectors, the identification of the bestanchorage can only be determined through detailed structuralanalysisl and, preferably, with actual crash testing. However,based OQ barrier behavior during past crash tests, anddiscussions with field engineers, anclnorage using through-bolts(one-inch diameter minimum), nuts, and washers’or plates andthrough-bolts appear to be more capable of resisting sh@ar,tension, and conical pullout failures, as well as reducing thepotential for improper installation of bolts since the use ofresin anchors will be limited.

In general, the design standards of the states visited do notspecify the moment capacity of anchoring devices for portableCSSBS . Officials of the states visited which use anchor boltsbelieve that the moment forces generated by impacting vehiclesare converted into tension forces which mus(t be resisted by thf$bolts .

47

v. CONCLUSIONS

A. Nine of the ten states studied anchor portable CSSBS inwork sites where they are needed, and where there isinadequate space behind them to accommodate energy-absorbing displacement without endangering drivers andworkers. Selected anchoring devices are designed tocontrol tilting, overturning, and sliding of barriers.Bridge construction, dropoffs close to edge of barriers,and barrier chains which cannot be interconnected becauseof sharp curves are common situations where verticalanchorage or slide prevention devices are used by thestates interviewed.

B. The minimum desirable space behind portable CSSBS is afactor in anchorage determination, but this measure hasnot been determined for the majority of barrier andconnector designs used today. Uncertainty in the behaviorof portable CSSBS when impacted by vehicles in work zoneswith restricted conditions is the primary reasons why nineof the ten states contacted use some form of verticalanchorage or slide prevention device.

c. Given the variety of barrier designs, connectors,pavement, and anchors, and that uniformity may not bepractical, there is need to develop performancespecifications for anchoring systems. Thesespecifications should be based on the individual designdetails of each barrier and connector group, but with theconsideration that all connectors of a certain class donot provide identical performance; for example, all pinand loop connectors may not exhibit identical performanceunder similar conditions.

D. Based on discussions with field officials in Pennsylvania,displacements reported in crash test reports, and fieldobservations of anchored portable CSSBS, anchorage on thetraffic side using a system of through-bolts, verticaldowels through barriers, nuts, plat@s, and washers appearsto be the preferred practice for Iong-tem work onbridges.

48

VI. RECONNENDATIONS

A. The AASHTO Roadside Desiqn Guide f=) (~) should discussthe need to anchor portable CSSBS and offer situationswhere anchorage should be considered. The RDG should alsoadvise on anchor treatments (with design details) tocontrol sliding, tilting, and overturnin~g. Currentpractice already substantiates the need for anchorage.

B. There is need for research on the behavior of anchoredportable CSSBS during highway accidents. Of interest isthe performance of the anchorage. Apparently, this typeof information is excluded from accident reports but isvaluable in identifying adeguate and ina.de~ate anchordesigns. Field officials are an untapped resource forthis type of information.

c. There is need for research to develop performancestandards for anchoring systems and to identify thecurrent anchoring systems which satisfy the standards.

D. Until the results of anchor research are available,practitioners should use anchoring systems which utilizedowel holes in barriers, through-bolts, nuts, washers, andplates instead of pins for anchoring portable CSSBS onbridges.

49

LIST OF REFERENCES

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

American Concrete Pavement Association, Concrete SafetvBarrier and Curb Manual, Arlington Heights, Illinois.

Wiles, E. O. and Bronstad, M. E. , Temporarv Barriers inConstruction Zones, Interim Report, Prepared by SouthwestResearch Institute for Federal Highway Administration,Washington, D.C., August 1976.

Bronstad, M. E., and Kimball, C. E., lSCrash Test Evaluationof a Precast Interlocked Median Barrier,nt Project No. 03-3777–002, Southwest Research Institute, San Antonio, Texas,August 1974.

Robertson, R. G., Barriers in Construction Zones, Volume 2:APP endix A, Report No. FHWA/RD–86/093, Federal HighwayAdministration, Washington, D.C., April 1985.

Ivey, D. L. et al., Barriers in Construction Zones, Volume1: Summarv Report, Report FHWA/RD–86–092, Federal HighwayAdministration, Washington, D.C., April 1985.

Ivey, D. L. et al., Barriers in Construction Zones - TheResnonse of Atv pical Vehicles Durinq Collisions withConcrete Median Barriers, Volume 4, Report No. FWA/RD–86/095, Federal Highway Administration, Washington, D.C.,April 1985.

Ivey, Don L. et al., ,Bportable Median Barriers: StructuralDesign and Dynamic Performance,” Transportation ResearchRecord No. 769, Transportation Research Board, Washington,D.C., 1980.

Graham, J. L., Loumiet, J. R. anti Migletz, J., PortableConcrete Barrier Connectors, Report No. FHWA TS-88-006,Federal Highway Administration, Washington, D.C., June 1987.

Institute of Transportation Engineers, ‘lPortable ConcreteBarrier Connectors,” ITE Journal Vol. 58, No. 4, April 1988.

West Virginia Department of Highways, Current Practices inthe Use of TemPorarv Concrete Barriers, Traffic EngineeringDivision, Charleston, West Virginia, November 1980.

Parks, D. N., Stoughton, R. L., Parker, J. R. and Mordlin,E. F., Vehicle Crash Tests of Unanchored Safetv-ShaDedPrecast Concrete Median Barriers with Pinned EndConnections, Report No. CA-DOT-TL-6624-1-76-52, CaliforniaDepartment of Transportation, Sacramento, August 1976.

50

12.

13.

14.

15.

16.

17.

la.

19.

20.

21.

Parks, D. N., Stoughkon, R. L., Sto:ker, J. R. and Nordlin,F. P., Vehicle Crash Test of A Continuous Concrete MedianBarrier Without A Footinq, Report No. FHWA-CA–TL6883–772–22,California Department of Transportation, Sacramento,California, August 1977.

Lisle, F. N. and Hargroves, B. T., :Evalua~~ion of thePerformance of Portable Precast Conzrete Traffic Barriers,Report No. VHTRC 79-R29, Virginia Highway and TransportationResearch Council, Charlottesville, ‘Virginia, November 1978.

Hahn, K. C. and Bryden, J. E. , flcrash Test of cOnstructiOn-

Zone Traffic Barriers,” Transportation Research Record No.~, Transportation Research Board, Washi]?gton, D.C., 1980.

Hahn, K. C. and Bryden, J. E., Crash Test of ConstructionZone Traffic Barriers, Report No. FHWA/NY/RR-80-82, FederalHighway Administration, Washington, D.C., June 1980.

Fortuniewicz, J. S., Bryden, J. E. and Phillips, R. G.,Crash Tests of Portable Concrete Median Barrier forMaintenance Zones, New York State Department ofTransportation, Engineering Societies Library, New York,December 1982.

Bureau of Highway Design, Standards for R>adwayConstruction, Commonwealth OE Pennsylvania Department ofTransportation, Harrisburg, Pennsylvania, May 1983.

Xarcum, Adam J., Desian and Evaluation of Temporary PrecastConcrete Barriers for Use on Ohio Bridqe :Decks, OhioDepartment of Transportation, Columbus, Ohio, 1988.

Marcum, Adam J., Guide for Installing Ternporarv PrecaseConcrete Barriers on Ohio Bridqe Decks, Qhio Department ofTransportation, Columbus, Ohio, June 1988.

U.S. Department of Transportation, Manual on Uniform TrafficControl Devices, Federal Highway Administration, Washington,D.c.r JUIY 1978.

American Association of State Highway and TransportationOfficials, Roadside Desiqn Guide, March 1989.

51

APPENDIX

STATE OF OHIODEPARTMENT OF TRANSPORTATION

DESIGN DEVELOPMENT ADMINISTWTIONBUREAU OF BRIDGES AND STRUCTUML DESIGN

August 8 , 1988

MEMO TO: Bureau Chiefs, District Deputy Directors, CountyEngineers and Consulting Engineers

FROM : B.D. Hanhilami, Engineer of Bridges and StructuralDesign

BY: Walter T. Florence, Assistant Engineer of Bridges

SUBJECT: Guide for Installing Temporary Precast ConcreteBarriers on Ohio Bridge Decks

Transmitted herewith is the above referenced manual to be used todetermine the following:

1. What modifications to make to Ohio’s existingtemporary precast concrete barrier (StandardConstruction Drawing MC-9A) to qualify it foruse on specific bridge decks.

2. Steps to be considered in the design of new(proposed replacement) temporary precast concrete

barrier for use on bridge decks.

3. Methods of installation and/or anchorage to beused in securing both types of temporary precastconcrete barrier on bridge decks.

Barrier use determination is based upon the concept of probable im-pact severity.

w fFBDH:WTF:serAttachment

52

GUIDE FOR INSTALLING TEMPORARY

PRECAST CONCRETE BARRIERS

ON OHIO BRIDGE DECKS

by Adam J. Harcum,

OHIO DEPARTMENT OF TRANSPORTATION

BUREAU OF BRIDGES AND STRUCTURAL DESIGN

?EVISIONS STATE OF OHIODEPARTMENT OF TWSPORTA,TION

BUREAU OF BRIDGES ~D STRUCTURAL DESIGN

APPROVED:

6-3u-gg .@&

DATE EN61NEER OF BRIDGESI

TABLE OF COWENTS

NOTICE ..........................................................1

BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

USE OF THE EXISTING OHIO BARRIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...2

THE PROPOSED OHIO BARRIER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...2

BRIDGE DECK SURFACE PREPARATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3

FIGURE 1 - MoDIFIED (EXISTING) BARRIER Details . . . . . . . . . . . . . . ....4

FIGURE 2 -PROPOSED BARRIER DETAILS . . . . . . . . . . . . . . ...............5

FIGURE 3 - PROPOSED BARRIER DETAIL AT HINGED CONNECTION .........6

FIGURE 4– JOINT CONNECTION DETAILS .............................6

BARRIER ANCHORAGE REQUIREMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...7

FIGURE 5 - IMPACT SEVRRITY VS ROADWAY WIDTH .....................8

FIGURE 6 - PLACEWNT VS IMPACT SEVRRITYOF AN UNANCHORED BARRIER CHAINCOMPOSED OFIO1 LONG SEWENTS ........................8

FIGURE 7 - ANCHORS REQUIRED PER 10’ BARRIER SEGMENTFOR MODIFIED (EXISTING) BARRIER mINs ...............9

FIGURE 8 - ANCHORS REQUIRED PER 10’ BARRIER SEGMENTFOR PROPOSED BARRIER CHAINS. .........................9

NOTICE :

THE CONTENTS OF ~IIS GUIDE REFLECTS THE VIEWS OF ~ PRE-

PARER AND THE BUREAU OF BRIDGES _ STRUmRAL DESIGN WHICN IS

RESPONSIBLE FOR THE ACCU~CY OF ~ DATA PRESENTED HEREIN. THE

GOAL OF THIS GUIDE IS TO ESTABLISE1 A ~IFOW DESIGN POLICY FOR

THE INSTALLATION OF TEMPORARY PRECAST CONCRETE BARRIERS ON OHIO

BRIDGE DECKS. THIS GUIDE IS INTENDED FOR THE IPRIVATE USE OF THE

OHIO DEPAR~ENT OF TRANSPORTATION, BUREAU OF BRIDGES AND STRUC-

TURAL DESIGN AND THEIR AGENTS. THE INFO~TIOIW CONTAINED HEREIN

IS SUBJECT TO PERIODIC REVIEW AND/OR REVISION BY THE ISSUING

AUTHORITY. THEREFORE, IT SHALL BE ~E DUTY OF THE DESIGNER, TO

ENSURE THAT HIS IS THE LATEST INFO~TION AVAILABLE. THIS GUIDE

SHOULD ONLY BE REPRODUCED AS A WHOLE. ANY COPYING OR DISTRIBU-

TION OF INDIVIDUAL PAGES IS TO BE DISCOURAGED.

1

BACKGROUND:

THIS GUIDE HAS BEEN COMPILED USING THB INFORMATION WHICH WASGATHERED AND/OR GENERATED DURING THS PREPARATION OF THE REPORT,“DESIGN ~ EVALUATION OF TEMPORARY PREcAST CONCRETE BARRIERS FORUSE ON OHIO BRIDGE DECKS”. COPIES OF THIS REPORT ARE AVAILABLEFROM THE OHIO DEPARTMENT OF T~SPORTATION, BUREAU OF BRIDGES ANDSTRUCTURAL DESIGN. ONLY BOLT CONNE~ED BARRIER DESIGNS ARE TO BEUSED IN CONJUNCTION WITH THIS GUIDE. THR USE OF PIN CONNE~ED ORTONGUE AND GROOVE BARRIER DESIGNS SHALL NOT BE PERMITTED ON OHIOBRIDGE DECKS.

USE OF THE EXISTING OHIO BARRIER:

BECAUSE OF THE INHERSMT WEAKNESS OF THE EXISTING OHIO BARRIER(STANDARD CONSTRUCTION DRAWING MC-9A, REVISED 1-11-85, CONNECTINGPIN TYPE), EVEN WHEN MODIFIED, CARE MUST BE TAKEN BY THE DESIGNERWHEN SPECIFYING ITS USE IN AREAS OF PROBABLE HIGH IMPACT SEVSRITY(OVER 45,000 FT-LBS). THE MODIFICATIONS TO BE WE TO THE EXIST-ING BARRIER, PRIOR TO ITS USE ON OHIO BRIDGE DECKS, ARE LISTEDBELOW AND SHOWN IN FIGURES 1 ON PAGE 4. USE FIGURE 5, PAGE 8, TODETERNINE THE IMPAcT SEVERITY.

1.

2.

3.

*

REPLACE CONNECTION PINS WITH 1 1/4 INCH DIA. HIGHSTRENGTH BOLTS.

FURTHER STIFFEN THE CONNECTION, WNERE REQUIRED *, BYFASTENING AN ANGLE (4”X 4“X 3/4”} TO THE BACK FACE OFJOINT .

LIMIT THE SLACK IN JOINTS BETWEEN SEGMENTS TO A MAXIMUMOF 3 DEGREES BY SHINMING AND/OR GROUTING THE JOINT.

WHEN THE EXISTING BARRIER IS USED IN ARSAS OF LOW TO MOD-ERATE IMPACT SEVERITY (30,000 FT-LBS OR LESS) THE STEELANGLE MAY GENERALLY BE OMITTED, SEE FIGURE 5, pAGE 8.

THE PROPOSED OHIO BARRIER:

THE EXISTING BARRIER HAS D~WBACKS, AS STATED ABOVE, TNATTEND TO RESTRI~ ITS USE ON BRIDGE DECKS. CORRECTING THESEFAULTS, IN ORDER TO PROVIDE A MORE CRASH-WOR= BARRIER, WOULDNECESSITATE THE FOLLOWING ACTIONS:

1. m STEEL ROD CONNECTOR LOOPS (HINGE BARS) SHOULD BEGRADE 60, MINIMUN YIELD STRENGTH OF 60,000 PSI, WITHINCREASED E~EDMENT.

2. THE CONCRETE USED SHOULD HAVK A MINIMUN COMPRESSIVESTRENGTH OF 4,000 PSI.

2

3. ~E BARRIER SEGMENT MST BE REINFORCED USING G~E60 REINFORCING STEEL. [THE PRESENT DESIGN ALLOWSF~RICATION WI~ LITTLE OR NO REINFORCING. )

4. THE JOINT SLACK ~THE DEGREE OF HORIZONTAL JOINTROTATION9 SHOULD BE REDUCED FROM ITS PRESEW VALUE OF8 DEGREES, DO~ TO A WI- OF 3 DEGREES.

~EN THE ~oVE -GES ~VE BEEN INCORPO~TED IWO A NEW PRE-CAST BARRIER DESIGN, IT SHOULD MEET ALL OF THE EXISTING REQUIRE-MENTS FOR TEMPORARY PRECAST CONCRETE BARRIERS. ~ESE NEW EARRIERSEGHE~S S~LL BE PE~EWLY ~RKED, FOR IDENTIFI~TION PURPOSES,WITH W APPROVED CODE SU~ AS ‘zBRD-u*$ [+wERE Z = mE YEAR CAST).FOR DETAILS OF ONE SU~ PROPOSED BARRIER DESIGW, SEE FIGURE 2.PAGE 5, OF THIS GUIDE. mE DESIGNER MY USE TKIS BARRIER, OR ONEOF A SIMILAR DESIGN AS APPRO~D BY THE DIRECTOR. ALL DESIGNSS~LL MEET OR ExCEED ~E DCSIGN REQUIREMENTS DESCRIBED IN THE RE-PORT , ‘*DESTGN AND EVALUATION OF TEMPORAR1? PRECAST CONCRETE BAR-RIERS FOR USE ON OHIO BRIDGE DECKS”. DESIGNS, AS SUBMITTED, S~LLBECOME THE PROPERTY OF ~E STATE OF OHIO,

BRIDGE DECK SURFACE PREPAWTION:

THE PROCEDURES ~ICN MUST BE FaLLaWED, WE,N INSTALLING ALLTEMPO=RY PRECAST CaNCRETE BARRIERS aN aHIa 8RIDGE DECKS, AREGIVEN BELOW.

A. THE BRIDGE DECK SURFACE AREA aN ~ICH THE PRE~STCONCRETE BARRIERS WILL REST, SmLL BE CLEARED aF ALLLOOSE SAND, GRAVEL, DIRT ~D DEBRIS.

B. ANY IRREGULARITIES IN THE BRIDGE DECK AREA, VWLESS ~DGEDBY THE ENGINEER TO BE INCONSEQUENTIAL, S~LL BE LEVELEDWITH GRaUT AND\OR ASP~LT.

c. AspmLT ROLL ROOFING S~LL BE PLACED aN THOsE BRIDGE DECKAREAS, AS JUDGED BY THE ENGINEER, TO NAVE A SURFACEROUGNNESS WHICH WOULD I~IBIT FRICTION CaNTACT BETWEENBARRIER SEGMENTS MD DECK.

3

( JOINT

TRAFFIc SIDEGROUTOR SHIM SNUGGLY

1< TEMPORARY

nT CONCRETE

BARRIER.

/ w /> / t

A “

Ill

L: I——— ___

4I

‘0 2 NO TRAFFIC SIDEY , ~

--

EDGEOF/

“’”” ‘E” PLAN AT JOINT

’411 ‘l:btA, H,:,‘BOLTWITi PLATEA WASHERS4N0 HEX NUT.II

4

‘~

L 483X4“ X $“

_ ~“ BOLTS, EMSED.2 5“ TO 6“, *

~‘m

t*EXPANSION BOLT PER CMS 712,01

OR EMBEDWITH NON-S HRINNEPOXY MORTAR PER SS 853/956

5“MlN,- OR PER SS 852/952 RESINANCHORS.

SECTION A-A

NOTES :

IN ORDER TO mCHOR mE MODIFIED (EXISTING) BARRIERTO THE BRIDGE DECK, WHERE ANCHORING IS REQUIRED,1-1/4,1 MIN. DIWETER HOLES WST BE DRILLED THROUGHTHE BARRIER TOE AT THE LOCATION SHOWN IN THE ASO~SECTION. GREAT. ~RB HOST BE USED IN DRILLING ANDINSTALLING THE BARRIER SEGMENTS , AS MY D~GB TOTHEM WILL BE cONSIDERED ~USE FOR THEIR REJECTION.

ALL ANCHORS SHALL BE 1‘!DIANETER , HIGH STRENGTH,TURU BOLTS OR APPROUED RESIN AN~ORS . WHEN RESINAN~lORS ARE USED, THEY NUST BE E~EDDED A MINI~OF 6‘tINTO FIW CONCRETE. THE NUNBER OF ANCHORSSHALL BE AS DBTEMINED BY FIGURE 7, PAGE 9.

ELEVATION AT JOINT

FIGuRE 1 - MODIFIED (ExISTING) BARRIER DETAILS

N.N

3’-0” l~o” 2:0” r- o“ 3: 0“’(- I 1 !

l:oa’ 4 SPA. 0 2~0’Cc/c=8’-O’n l~o”

‘IEW A-A

s

TO ~E PROPOSEDEQUAL , SNALL BE

“BRD-=” (-RE

/

SECTION B-B

NOTE :

SEGNENTS WE ACCORDINGDESIGN, OR AN APPROWDCLEARLY ~KED , SUm AS= = THE YEAR ~ST ) .

ALL AN~ORS SWL BE 1,,DIWETER,HIGH STRENGm , THRU BOLTS OR APPROWI)RESIN AN~ORS . ~EN RESIN AN~ORS AREUSED , THEY NST BE E~EDDED A HINI~[oF 6” INTO FIm CONCRETE. mE mEROF AN~fiORS S~LL BE AS DETEWINED BYFIGURE 8, PAGE g.

FIGURE 3 - PROPOSED %ARRIER DETAIL AT HINGED CONNECTION

OPEN JOINTO CLOSED$JOINT @

~ BARRIER JOINTS MUST BE FULLY @ BARRIERS SHOULD INITIALLY BE

OPEN BEFORE NUT IS TIGHTENEO PLACED CLOSER ToGETHER SO THAT

ONTO BOLT AND OPENING IS BOLTS CAN 5E EASILY INsERTEO

EITHER GROUTEO OR SHIMMED. THROUGH HINGE BAR LOOPS.

FIGURE 4 - JOINT CONNECTION DETAILS6

BARRIER ANCHORAGE REQUIREMENTS:

THE ANCHORAGE REQUIRB~~S FOR TEMPO~Y PRECAST CONCRETEBARRIERS ~ BE DETERMINED BY USING ~E FOLLOWING PROCEDURES.

1. ENTER FIGURE 7, PAGE 9, WITH ~ KNOWN ROADWAY WID~ ANDTHE POSTED SPEED LIMIT * AND FIND THE mER OF AN~ORSREQuIRED WEN THE MODIFIED (EXISTING) BARRIER DESIGN ISUSED .

ORENTER FIGURE 8, PAGE 9, WITH ~E f~OWN ROADWAY WID~ ANDTHE POSTED SPEED LIMIT * AND FIND ~E mER OF AN~ORSREQUIRED ~EN ~E PROPOSED B~IER DESIGN IS USED.

2. IF ~E BARRIER INSTALLATION IS TO RE~IN UNANCHORED,EITNER BECAUSE OF LOW IMPACT SEVERITY OR THE AVAILA-BILITY OF SPACE BE~EEN THE BARRIER AND TNE EDGE OF THEBRIDGE DECK, ENTER FIGURE 5, PAGE 8, WI~ THE RWOWN ROAD-WAY WIDTH AND ~E POSTED SPEED LIMIT * ~ FIND THE IM-PACT SEVERITY. THEN, WITH THE KNOWN IMPACT SEVERITY,ENTER FIGURE 6, PAGE 8, AND FI~ WE MINI- CLEAR DIS-TANCE REQUIRED FROM THE EDGE OF THE BRIDGE DECK AT WHICHmE BARRIER (MODIFIED OR PROPOSED) m BE LOmTED.

* THE POSTED SPEED LIMIT SHALL BE DEFINED AS THE SPEED TNATIS ACTIVELY ENFORCED EITHER BY LEGAL MEP~S OR TRAFFIC CON-TROL DEVICES.

ALL BARRIER SEGMENTS SHALL, WHERE REQUIRED, BE FASTENED TOTNE BRIDGE DECK USING ONE INCH DIWETER HIIGH STREN~ THRU BOLTSOR APPROVED RESIN ANCHORS. WHEN RESIN ANCHORS ARE USED THEY MUSTBE EMBEDDED A MINIm OF 6“ INTO FIW ~NCRETE. GENERALLY, ALLWCHORS SHALL BE PLACED ON THE TRAFFIC SIDE OF THE BARRIER WITHTHE ANCHOR PATTERN SYMMETRICAL ABOUT ~E CENTER OF EACH TEN FOOTSEGMENT . EVEN TNOSE PRECAST CONCRETE BARRIER SEGMENTS NOT OTHER-WISE REQUIRING ANCNORING S-L, ~EN LOCATED ON BRIDGE DECKSCROSSING OVER ROADWAYS, RAILROADS, ~/OR RECREATIONAL AREAS, BESECURED BY NO LESS T- TWO ANCHORS **.

** ~LEss BARRIER sEGME~s ME To BE INSTALLED 6 ~- OR noR~

(CLEAR DISTAWCE ) FROM ~E EDGE OF DECK, EQUIPMENT, AND/ORPROB~LE WORK ~EAS.

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