pile driving inspector course - ctqpflorida.com driving/06 - mod_6_contractor... · october 2018...

October 2018 Pile Driving Inspector Release 10, Module 6-1

Florida Department ofTRANSPORTATION

Pile Driving Inspector Course

Module 6: Contractor Equipment and Piles Arrive on Site

Module 6: Contractor Equipment & Piles Arrive On- Site

Release 10 July 2018 6-1

Pile Driving Inspector



Learning Outcomes• Verify and document equipment matches accepted Pile

Installation Plan

• Document Contractor compliance with protection of existingstructures, excavations, etc.

• Verify Contractor compliance for transportation, handling,storage, labeling & marking of piles

• Identify Contractor provided elevations

When the Contractor and equipment arrive on-site, the Inspector has a variety of many things to check from verifying that the Contractor has initiated their Protection of Existing Structures to verify that the equipment brought on site matches that one included in the accepted Pile Installation Plan.






Section 108Monitor Existing Structures

108-1 Description.Provide settlement, vibration and groundwater monitoring in accordance with the requirements of this Section. The work required under this Section does not modify the requirements or responsibilities for preservation of existing property from damage in accordance with 7-11.1. Evaluate the need for, design of, and provide any necessary precautionary features to protect existing structures from damage. Employ construction methods that will not produce damaging vibrations, soil movement, soil loss, or instability of existing structures.






108-2 Construction.108-2.1.2 Structures other than Miscellaneous: When excavating orconstructing retaining walls and foundations for bridges, buildings, andstructures other than miscellaneous structures, inspect and document thecondition of the following existing structures, and survey and monitor forsettlement the following existing structures:

1. as shown in the Plans.

2. within a distance of five shaft or auger cast pile diameters, or theestimated depth of drilled shaft or auger cast pile excavation, whichever isgreater, measured from the center of these foundation elements.







108-2.1.2 Structures other than Miscellaneous: (cont’d)

3. within a distance of three times the depth of any other excavations.4. within 200 feet of sheet pile installation and extraction operations.5. within 100 feet of steel soldier pile installation and extraction operations.







108-2.1.2 Structures other than Miscellaneous: (cont’d)

6. for projects with pile driving operations, inspect and document thecondition of all structures within a distance, in feet, of pile drivingoperations equal to 0.25 times the square root of the impact hammerenergy, in foot-pounds. Survey and monitor for settlement all structureswithin a distance, in feet, of pile driving operations equal to 0.5 times thesquare root of the impact hammer energy, in foot-pounds.







108-2.1.5 Settlement Surveying and Monitoring Requirements: Obtain theEngineer’s approval for the number and location of monitoring points. Surveyand monitor the settlement of structures, recording elevations to 0.001 foot:

1. before beginning construction2. daily, during the driving of any casings, piling, or sheeting,3. daily, during compaction4. daily, during foundation drilling







108-2.1.5 Settlement Surveying and Monitoring Requirements: (cont’d)

5. weekly, for two weeks after stopping pile driving6. during excavation7. during blasting8. or, as directed by the Engineer

Upon either detecting movement of 0.005 feet or damage to the structure, immediately stop the construction operations affecting the structure, backfill any open excavations, notify the Engineer and submit a corrective action plan for acceptance by the Engineer.







Distance for Monitoring Structures

Distance from Pileto be monitored (D) for

settlements

D

0.5 x Hammer Energy (Ft-lbs.)D =English

Here is a graphical representation of the settlement monitoring requirements for pile driving. Structures within the radius given by the equation must be monitored for settlements.






Distance for Surveying Structures

Distance from Pileto be inspected (D)D

D = 0.25 x Hammer Energy (Ft-lbs.)English

And here is a graphical representation of the pre-construction and post-construction survey monitoring requirements for pile driving. Structures within the radius given by the equation must be inspected prior and after construction operations.







108-2.1.4 Inspection and Documentation Requirements: Inspect anddocument the condition of the existing structures and all existing crackswith descriptions and pictures using a qualified Specialty Engineer. Preparetwo reports documenting the condition of the structures: one reportbefore beginning the construction operations that may affect the existingstructures such as but not limited to foundation construction, excavations,vibratory compaction, dewatering and retaining wall construction, and asecond report after completing such construction operations.







108-2.1.4 Inspection and Documentation Requirements: (cont’d) Include inthe reports the Specialty Engineer’s assessment of any damage present, andin the event of damage, the Specialty Engineer’s assessment of whether theobserved damage is the result of the construction operations. Submit bothreports to the Engineer. Inspecting and documenting the condition ofbridges, sign, signal, lighting and ITS structures owned by the Department isnot required except when shown in the Contract Documents.

The Department will make the necessary arrangements to provide right of way entry to the existing structures.






108-2.2 Vibration Monitoring: When shown in the Contract Documents,employ a qualified Specialty Engineer to continuously monitor and recordvibration levels at the structures shown in the Plans during the operation ofany equipment causing vibrations or during blasting operations. Submit thevibration records to the Engineer within 24 hours of performing themonitoring activity. Provide vibration monitoring equipment capable ofdetecting velocities of 0.01 inches per second or less. Obtain the Engineer’sapproval of the number and locations of the monitoring points.


There is no equation based on Energy to monitor vibrations. The need for monitoring vibrations needs to be spelled out in the plans.






108-2.2 Vibration Monitoring: Upon either detecting vibration levels reaching0.5 inches per second or damage to the structure, immediately stop the sourceof vibrations, backfill any open excavations, notify the Engineer and submit acorrective action plan for acceptance by the Engineer.


There is no equation based on Energy to monitor vibrations. The need for monitoring vibrations needs to be spelled out in the plans.






Learning OutcomeA hammer has a rated energy of 99,400 ft. lbs.

Answer the questions below.

1. Structures within what distance should be monitoredfor settlements by the Contractor?

2. Structures within what distance should be inspectedand monitored for settlements by the Contractor?


Release 10 October 2018 6-15




Learning OutcomeWe are using a hammer with a rated hammer energy of 106,020 ft-lbs. Structures are located at the distances shown below. Which ones need to be monitored only and which ones need to be both inspected and monitored?

Structure A 76 ft.Structure B 140 ft.Structure C 120 ft.Structure D 80 ft. Structure E 96 ft.

Which structures need settlement monitoring only?

Which structures need inspection and monitoring of settlements?

Please resolve the following review questions. A hammer has a rated energy of 106,020 ft. lbs..

Which structures need monitoring only?

Which structures needSurveying and monitoring?






Learning OutcomeIf an adjacent structure settles 0.01 ft during pile driving,what should the contractor do:

A. Stop monitoringB. Stop drivingC. Notify EngineerD. Submit corrective action






Learning OutcomeThe Contractor is performing settlement monitoring duringpile driving. Which of the following is correct:

A. Use equipment that allows the recording of elevations to 0.01 ftB. Use equipment that allows the recording of elevations to 0.05 ftC. Use equipment that allows the recording of elevations to 0.001 ftD. Use equipment that allows the recording of elevations to 0.1 ft






455-1.2 Excavation

455-1.2 Excavation: Complete all excavation of the foundations prior toinstalling piles or shafts unless otherwise authorized by the Engineer.After completing pile/shaft installation, remove all loose and displacedmaterials from around the piles/shafts, leaving a clean, solid surface.

Here the specifications refer to the excavations required to construct the footers or pile cap. These need to be done prior to install the piles.






455-1.2.1 Abutment (End Bent) Fill455-1.2.1 Abutment (End Bent) Fill: Place and compact the fill beforeinstalling end-bent piling/shafts, except when driving specified testpiling in end bents or the Plans show uncased piles throughproprietary retaining wall fills.

When installing piles/shafts or casing prior to placing fill, take necessary precautions to prevent displacement of piles/shafts during placing and compacting fill materials within 15 feet of the piles/shafts or casing. Reference and check the position of the piles/shafts or casing at three approximately equal intervals during construction of the embankment.






455-1.3 Cofferdams• If not in Plans, must employ Specialty Engineer for design

• Provide diver and safety diver

• Equip with voice communications

Contact the PA for specifics on each project.

If the cofferdams design is not addressed in Plans the Contractor must employ Specialty Engineer to design it.

The Contractor must Provide diver and safety diver equipped with voice communications devices to inspect the final conditions of the foundation enclosure.







455-1.3 Cofferdams455-1.3 Cofferdams: Construct cofferdams as detailed in the Plans.When cofferdams are not detailed in the Plans, employ a qualifiedSpecialty Engineer to design cofferdams, and to sign and seal theplans and specification requirements. Submit the designs to theEngineer for their records before beginning construction.







455-1.3 Cofferdams (cont’d)

Provide a qualified diver and a safety diver to inspect the conditions of the foundation enclosure or cofferdam when the Contract Documents require a seal for construction. Equip these divers with suitable voice communications, and have them inspect the foundation enclosure and cofferdam periphery including each sheeting indentation and around each piling or drilled shaft to ensure that no layers of mud or other undesirable materials were left above the bottom of seal elevation during the excavation process. Also have the divers check to make sure the surfaces of the piles or drilled shafts are sufficiently clean to allow bond of the concrete down to the minimum bottom of seal elevation.







455-1.3 Cofferdams (cont’d)

Ensure that there are no mounds of stone, shell, or unapproved backfill material left after placement and grading. Assist the Engineer as required to ensure that the seal is placed as specified and evaluate the adequacy of the foundation soils or rock. Correct any deficiencies found by the divers. Upon completion of inspection by the divers, the Department may also elect to inspect the work before authorizing the Contractor to proceed with subsequent construction operations. Submit a written report by the divers to the Engineer indicating the results of their underwater inspection before requesting authorization to place the seal concrete.






Inspector Responsibility

VERIFYING, DOCUMENTING

Introduction to Inspector Responsibilities






Checking EquipmentEquipment

• Delivery, Handling & Storage of Piles

• Marking & Location of Pile

• Templates

• Reference Points/Elevations

• Jetting/Preformed Holes

• Splices

• Pile Driving Operations

Inspector has various responsibilities, such as:

• verifying the correct equipment is on the job.

•Verify the Delivery, Handling &Storage of Piles

• Verify the Marking & Locationof Piles

• Verify Templates

• Verify that Reference Points/Elevations are provided

• Observe Jetting/Preformed Holes operations

• Observe construction of Splices

• Monitor and record Pile Driving Operations






Check HammerCheck Hammer

• Manufacturer

• Model

• Type

• Serial Number

• Energy Rating

• Ram Weight

• Ram Stroke

The Contractor specified in their plan, the details on the pile drivingsystem, including hammer, helmets and cushions. Once the plan isapproved, there are to be no changes without the Engineers’approval.

As Inspector, you need to verify that the equipment matches theapproved plan. The hammer model, serial number, energy ratingshould match, as well as the cushion materials and thickness, andhelmet (cap block) dimensions.






Checking Equipment

For air/steam or hydraulic hammer, is the power source correct?

Are calibrated gauges provided for reading pressures?

Typical control panelOn power source.

It is important to have the right external power supplies and workinggauges to monitor power.

The calibration frequency is typically set forth in the specificationsand is generally within the last 90 days.






Checking Equipment

Typical control panel on power source

Here is a Typical control panel for a hydraulic hammer






Checking Equipment

For air/steam, is a slide bar for setting stroke

height provided?

In air hammers a slide bar is used to set up the stroke heights.

In the photo, the slide bar is set in the cog for full stroke. The other cog is for half stroke.






Checking Equipment

For closed end diesel hammers is a calibrated bounce

chamber gauge provided?

Here is a bounce chamber pressure gauge for closed end diesel hammers.






Check LeadsAre the leads the same as specified in the Pile Installation Plan ?

The leads perform the very important function of holding thehammer and pile in good alignment with each other. Pooralignment reduces energy transfer as some energy is then impartedinto horizontal motion. Poor alignment also generally results inhigher bending stresses and higher local contact stresses whichcan cause pile damage. This is particularly important at end ofdriving when driving resistance is highest and driving stresses aregenerally increased. Sometimes the specifications do not allowcertain lead systems or may require a certain type system. A pilegate at the lead bottom which properly centers the pile should berequired, as it helps maintain good alignment.

The Inspector needs to verify that the Contractor brought the leadsthat were approved in the Pile Installation Plan.

Was a fixed lead system, like that shown here, approved and theleads on-site are swinging, or semi-fixed?






Check Leads

Are the leads long enough to hold the maximum pile length and hammer in alignment?






Check Helmet

The Inspector is to verify that the weight, diameter and depth of thedrive head is as presented in the Pile Installation Plan.

It needs to fit loosely over the pile to be driven and also havesufficient room to accommodate the required hammer cushion.

Generally, the diameter is slightly larger than the pile diameter. Fitis more critical for concrete piles.






Check Hammer Cushions

The Contractor’s Plan and the Driving Criteria Letter, will containhammer cushion data. Check to see that the cushions are in goodcondition.

A single polymer cushion typically will be 2” thick.







This slide shows a Micarta (phenolic canvas) cushion at your leftand a hammortex cushion at your right.

If the hammer cushion is to consist of several components, forexample, a Hammortex sandwiched with aluminum disks, then the“sandwich” thickness is measured and the “sandwiching” comparedto the approved plan.







Here is an inspector verifying the measurements of a hammercushion.






Check Pile Cushions

Pile Cushions are made of plywood or oak lumber. Note in the lefthand photo there are 8 pieces of plywood, which at ¾” each wouldprovide for a 6” cushion.

The Inspector needs to measure the cushion for the minimumthickness requirement. A specified thickness may be noted in thePile installation Plan or Driving Criteria letter. If, for example, it isspecified that the pile cushion is to be 6” thick, the Inspector needs toverify that thickness.






Check Pile Cushions

Here is a short video showing theinstallation of the pile cushion into the helmet.






Checking Piles• Equipment

• Delivery, Handling & Storage of Piles

• Marking & Location of Piles

• Templates

• Reference Points/Elevations

• Jetting/Preformed Holes

• Splices

• Pile Driving Operations

It is extremely important that piles, specifically concrete, be lifted,transported and stored properly to ensure adequate supportthroughout their length. Improper lifting or storage can causebending of the piles, and in the case of concrete can causemicrocracks. Typically, details for lifting and support (dunnage) ofpiles is shown in the contract documents.

Piles should be inspected as they arrive from the prestress yard.

• Look for visible damage to the pile• Check for production dates and “Acceptance” stamp• Match pile lengths with authorized casting lengths• Check that lifting eyes have been removed and epoxied at thecasting yard. This should include checking that the prestressingstrands have been properly removed.• Verify that handling and storage on-site complies with the PlanSheets and Standard Plans.






Checking Piles

Here is short video showing piles on-site.

The Inspector needs to check casting date, pile number, etc. Pilemay have casting date and stamp as discussed earlier or may beaccompanied by paperwork.






Checking Piles

Compare diameter,length and wall

thickness to plan details.

Pipe Piles:

For steel pipe piles, measure the diameters, wall thickness andlengths and compare to the plans.






Piling Storage

Here is a picture of steel piles being stored with dunnage.






Checking PilesMeasure the Pile Depth and Flange Width for comparison

to plan details.

10 X 59 =

H piles:

This is an illustration of a 10 x 59 H pile.

H Piles are typically identified by the pile depth and the flange width and weight per foot.

In this slide this is a 10” x 10” pile with a linear weight of 59 lbs perfoot






Checking Piles

This table indicate the typical H pile sizes. In parenthesis is the designation for the metric system equivalents.

A typical ticket is shown at the right of the slide.






Timber Piling

Check lengthand straightness.

Timber piles generally arrive at the site in the required lengths. It isnot very common to splice timber piles and is prohibited by thespecifications.






Timber Piling

455-6.2 Materials: Meet the timberpiling requirements of Section 953.Treat the piles according to theapplicable provisions of Section 955.Treat all cuts and drilled holes inaccordance with 470-3.

Physical details for round timber piles are sometimes referred to in the ASTM pile specification, ASTM D25. Regardless of the referenced specifications, the following items should be checked for compliance:






Timber Piling (cont’d)

a. The timber should be of the specified species.

b. The piles should have the specified minimum length, and have the correct pile toe and butt sizes.

c. The pile butt must be cut squarely with the pile axis.d. The twist of spiral grain and the number and distribution of knots should

be acceptable.

e. The piles should be acceptably straight.

f. The piles must be pressure treated as specified.

g. The pile butts and/or toe may require banding per the specifications.

h. Steel shoes which may be specified must be properly attached.






Piling Storage

This slide shows prestressed concrete piles being stored with timber block supports. These supports must be a spacings not exceeding those indicated in the Standard Plans.






455-7 Prestressed Concrete Piling455-7.3 Storage and Handling:

455-7.3.1 Time of Driving Piles: Drive prestressed concrete piles at anytime after the concrete has been cured in accordance with Section 450,and the concrete compressive strength is equal to or greater than thespecified 28 day compressive strength.455-7.3.2 Storage: Support piles on adequate dunnage both in theprestress yard and at the job site in accordance with the locations shownin the Standard Plans to minimize undue bending stresses or creating asweep or camber in the pile.






455-7 Prestressed Concrete Piling455-7.3.3 Handling: Handle and store piles in the manner necessary toeliminate the danger of fracture by impact or of undue bending stresses inhandling or transporting the piles from the forms and into the leads. Ingeneral, lift concrete piles by means of a suitable bridge or slings attachedto the pile at the locations shown in the Standard Plans. Construct slingsused to handle piles of a fabric material or braided wire rope constructedof six or more wire ropes which will not mar the corners or the surfacefinish of the piles. Do not use chains to handle piles.






455-7 Prestressed Concrete Piling455-7.3.3 Handling: (cont’d) During transport, support concrete piles at the liftinglocations shown in the Standard Plans or fully support them throughout 80% ormore of their length. In handling piles for use in salty or brackish water, exercisespecial care to avoid damaging the surface and corners of the pile. If an alternatetransportation support arrangement is desired, submit calculations, signed andsealed by the Specialty Engineer, for approval by the Engineer prior totransporting the pile. Calculations must show that the pile can be transportedwithout exceeding the bending moments calculated using the support locationsshown in the Plans.






455-7.4 Cracked Piles: The Engineer will reject any pile that becomes crackedin handling to the point that a transverse or longitudinal crack extendsthrough the pile, shows failure of the concrete as indicated by spalling ofconcrete on the main body of the pile adjacent to the crack, which in theopinion of the Engineer will not withstand driving stresses, or becomesdamaged during installation. The Engineer will not reject any pile for theoccasional minor surface hairline cracking caused by shrinkage.

455-7 Prestressed Concrete Piling

Inspectors must note the “damage”, document with photographs,and report to PA.

It is not the Inspector’s responsibility to make final decisions onthese piles.






Cracked Piles

The Inspector cannot reject a pile, that is the PA’s authority.

Inspect concrete piles closely for damage. If any is evident,document and contact the Project Administrator for instructions.






Two-Point Pick: Concrete Pile

Here is a short video that shows an improperly lifted concrete pile using two pick up points. Notice the bending of the pile.






Three-Point Pick: Concrete Pile

This short video shows a concrete pile being lifted by 3 pick up points. Notice in this case there is not bending as in the previous case.






Standard Plans, Index 455-001

Pick up points and support details for prestressed concrete piles:

Here is the Standard Plans, Index 455-001 that specifies therequirements for pick up and support points.

The Contractor is typically required to mark their lifting points basedupon the plan details.

The Inspector should double-check the Contractor’s marks bymeasuring the length of pile, the diameter (size) and then refer tothe plan details to verify the marks are correct.

The next slide will show a detail of the required spacing's for pickup and storage.






Pickup & Support Details

Here is a detail of the required distances or spacing’s for pick uppoints and for storage and transport points. These distances willvary depending on the size of the pile. The smaller the size of thepile, the shorter the required distances between supports. The nextexercise will illustrate the use of this index.

The full size standard plan index 455-001 is included in theAppendices. Use it for the next exercise.






Learning OutcomeFor a Precast Concrete Pile, 18” sq.: 65 ft. in length

1. Where should the pick up points be?

2. Where should the support be for a 3-point support ?

Please work out this problem. Use the standard plans index 455-001 included in the Appendices.






Learning Outcome

Please work out this problem. Use the Standard Plan Indexincluded in the Appendices.






Checking Piles

Checking Piles:

The inspector needs to document the conditions of the piles as theyarrived to the site. Inspector needs to verify that the strands havebeen properly removed, the lifting eyes have been properlyremoved and patched and that the piles arrived to the site withoutdamage.

Also the inspector needs to verify that piles are handled properly.Document if the Contractor did not use support points and pick-uppoints in accordance to the standard plan index we just covered.

Here is a picture of a concrete pile with bending cracks due to poorhandling. Cases like this must be recorded, documented,photographed and brought to the attention of the PA.







455-7.5 Preparation for Transportation: Cut strands flush with thesurface of the concrete using an abrasive cutting blade beforetransporting the piles from the casting yard.

Cut and patch the metal lifting devices in accordance with 450-9.2.1.






455-7 Prestressed Concrete Piling450-9.2.1 Inserts and Lifting Devices:450-9.2.1.1 Placement: Locate inserts and lifting devices inaccordance with the tolerances listed in 450-2.1. Use only non-metallic inserts and lifting devices with CFRP reinforced piling.450-9.2.1.2 Corrosion Protection: After lifting operations using flushor protruding metallic or non-metallic lifting devices are complete,cut the lifting devices back to a minimum depth of 1 inch below theconcrete surface and patch with a Type F epoxy compound meetingthe requirements of Section 926. For all square prestressed piling,concrete sheet piling and concrete poles, cut and patch lifting devicesbefore transporting from the casting yard.






Checking Piles

The Inspector must verify that the strands have been removedproperly.They must be cut with an abrasive cutting blade- not burnt off asshown here.






Checking Piles

Lifting eyes

Shown in the photo are the lifting eyes cast in at the yard tofacilitate lifting the pile from the form after casting.

As reviewed earlier, our specifications require these be removedand patched with epoxy prior to leaving the casting yard andarriving at the jobsite.






455-7.6 Method of Driving: Unless otherwise directed, drive piles bya hammer or by means of a combination of water jets and hammerwhen jetting is allowed. When using jets in combination with ahammer, withdraw the jets and drive the pile by the hammer aloneto secure final penetration and to rigidly fix the tip end of the pile.Keep jets in place if they are being used to continuously eliminate thesoil resistance in the scour zone.







Check Templates

Check templates:

The Inspector must verify that the Contractor is adhering to theirPile Installation Plan sequencing, use of jets, templates, leads, etc.,part of which is to check the template construction against theapproved plan template.

Discrepancies to the approved plan should be pointed out anddocumented and the PA contacted.






Document Elevations

If a template is being used, it provides a great reference (elevation).When templates are used they are used as reference elevations aswell. When fixed leads are used and no templates are used, thenanother suitable reference (batter board, string line, etc.) will need tobe established. Have Contractor provide you the elevation.

At all possible, avoid using a reference that moves or will need to bemoved before completing driving of the pile.

Typically this will be the template, as shown here in the photo.For Fixed Lead system, will need to set a string line or similar.

The reference elevation is marked by the Contractor.

Discuss emphasizing importance ofselecting a reference that will not need to be moved. Needs to bestable.

If reference is moved, then Inspector needs to recalculate “Min. TipTarget” “Stop for Set-Check Cut-off Target.” Also needs to notechange in Pile Driving Record.






Learning Outcomes• Verify and Document Equipment Matches Approved Pile

Installation Plan

• Document Contractor Compliance with Protection of ExistingStructures, Excavations, etc.

• Verify contractor compliance for transportation, handling,storage, labeling & marking of piles

• Identify Contractor provided elevations






ANY QUESTIONS ?


