160235.00 ● Final Report ● January 2017

Killam’s Wharf Assessment Report Yarmouth, NS

Prepared by: Prepared for:

Town of Yarmouth

Greg Peters Paul Hamson

Final Report January 2017

Issue or Revision Reviewed By: Date Issued By:

This document was prepared for the party indicated herein. The material and information in the document reflects CBCL Limited’s opinion and best judgment based on the information available at the time of preparation. Any use of this document or reliance on its content by third parties is the responsibility of the third party. CBCL Limited accepts no responsibility for any damages suffered as a result of third party use of this document.

160235.00 RE001 KILLAM'S WHARF ROCKWALL FINAL REPORT.DOCX/KL ED: 17/01/2017 13:52:00/PD: 17/01/2017 13:52:00

January 17, 2016 Town of Yarmouth David Ernst, P.Eng. 400 Main Street Yarmouth, NS B5A 1G2 Dear Mr. Ernst: RE: Killam Wharf Assessment Please accept this Final Report for the Killam Wharf Assessment on behalf of CBCL Limited. If you have any questions or concerns, please do not hesitate to contact us. Yours very truly, CBCL Limited Greg Peters, M.A.Sc., P.Eng., P.E. Senior Structural Engineer Direct: (902) 421 7241 ext. 2229 E-Mail: gregp@cbcl.ca Project No: 160235.00

CBCL Limited Killam’s Wharf Rockwall Final Report i

Contents

CHAPTER 1 Introduction ........................................................................................................ 1

1.1 Authorization ................................................................................................................ 1

1.2 Background ................................................................................................................... 1

1.3 Method of Inspection ................................................................................................... 2

CHAPTER 2 Description of Structures ...................................................................................... 3

2.1 Killam’s Wharf ............................................................................................................... 3

CHAPTER 3 Condition Assessment .......................................................................................... 4

3.1 Killam’s Wharf Rock Wall .............................................................................................. 4

3.1.1 General Observations ....................................................................................... 6

CHAPTER 4 Recommendations ............................................................................................... 8

4.1 Short Term Displacement Monitoring Program ........................................................... 8

4.2 Long Term Stabilization Solutions ................................................................................. 8

4.2.1 Option 1 – New Rock Slope with Wharf Extension ........................................... 8

4.2.2 Option 2 – New Sheet Pile Stabilization ........................................................... 9

CHAPTER 5 Opinion of Probable Cost ................................................................................... 10

5.1 Closure ........................................................................................................................ 10

Appendices A exp. Services Inc. Report B Drawings C Opinions of Probable Costs

CBCL Limited Killam’s Wharf Assessment Final Report 1

CHAPTER 1 INTRODUCTION 1.1 Authorization This report is part of an assignment consisting of the condition assessment of the rock walls at Killam`s Wharf in Yarmouth, Nova Scotia. The Scope of the work is based on a proposal dated August 17, 2016 from Greg Peters of CBCL Limited (CBCL) to David Ernst, P.Eng., Director of Infrastructure Renewal and Asset Management for the Town of Yarmouth. 1.2 Background Killam`s Wharf is located in the Yarmouth harbour. Its main uses are as a marina and waterfront boardwalk. The wharf consists of the rock walls in question, and a 1 m high concrete wall on top of the rock wall. Behind the wall is a concrete slab on grade supported on backfill. There is a 5 m wide timber wharf surrounding the concrete area. The timber structure is supported on the concrete wall on the inside and 28 timber piles on the outside. The Town of Yarmouth supplied photos taken of the rock wall structure taken at an unknown time. The wharf is situated at approximately 90 Water Street, Yarmouth NS. The total structure is approximately 22 m long and 40 m wide. The width and height of the rock wall underneath varies. The approximate latitude and longitude are 43°50'10.89"N and 66° 7'21.03"W respectively. For reference, the face of the wharf towards the harbour is the west side of the structure with road access on the east side. The location of structure is illustrated in Figure 1.

Figure 1: Location of Killam Wharf in Yarmouth, NS

CBCL Limited Killam’s Wharf Assessment Final Report 2

1.3 Method of Inspection The rock wall at the Killam`s wharf was inspected on August 23rd, 2016 by Bruce Higgins, P. Eng. and Erin Carroll of CBCL. The rock wall was accessible by foot, by crawling under the timber sheathing at low tide. According to the tide tables, low tide reached 0.5 m chart datum at 8:50am. The top of the rock wall was accessible through access panels that were removed on each side of the timber deck.

CBCL Limited Killam’s Wharf Assessment Final Report 3

CHAPTER 2 DESCRIPTION OF STRUCTURES 2.1 Killam’s Wharf Killam’s Wharf includes an approximately 17 m long and 30 m wide concrete slab on grade, with a 5 m wide timber apron, making it 22 m long and 40 m wide in total. There are three segments of rock wall underneath the wharf decking, approximately 75 m long in total, with an approximate 1 m tall concrete wall on top of the backfill, retained by the rock wall, all holding in the granular fill. The timber deck is supported on 100 mm wide x 150 mm deep stringers, which in turn, are supported by 300 mm x 300 mm pile timber pile caps. The timber pile caps span between the concrete wall (inside of the deck) to 300 mm diameter timber piles (outside of the deck). For reference, the piles are numbered from 1-28 starting at the north-east corner and going around the wharf in a counter-clockwise manner. The outside of the wharf has 80 thick X 150 wide open faced timber sheathing. The height of the rock wall varies from approximately 3 to 4.3 m high. The width is not readily visible, but appears to be at least 1 m.

CBCL Limited Killam’s Wharf Assessment Final Report 4

CHAPTER 3 CONDITION ASSESSMENT Field observations for above the water are summarized in the following table and are also shown on drawings S01 and S02 in Appendix B. This includes items recorded by CBCL Limited. Generally, deficiencies and notable observations are recorded. Components that are not noted do not have readily apparent significant problems. 3.1 Killam’s Wharf Rock Wall The existing conditions for the rock wall are tabulated below. For reference, batter or slope of the face of wall is reported as the ratio of the horizontal dimension of the slope to the vertical component. Positive batter indicates that the top of wall leans inward and negative batter that the top of wall leans outward. Notes at the wall face include whether the rock face is chinked, or small rocks are inserted in the remaining spaces between the main stones in the wall. Vertical seams refer to areas where the rocks in the wall are placed such that vertical joints in the wall are aligned in successive courses, rather than being staggered. Good bearing refers to where rocks in the wall face contact and are supported on two rocks in the course below, while slope typically refers to whether the support at the bottom of the rock is inclined away from the rock face.

PILE NO. COMMENTS PHOTO NO. NORTH SEGMENT

1-3

Dimensions: 3.4 m high x 1 m+ wide with a -0.15 to 0 batter, wall face is offset 1.3m from the edge of the wharf.

Wall Face: 50% chinked. Construction: Fair bearing and slope on rocks in wall, bottom consists of gravel

3-5

Dimensions: 3.6 m high x 1.3 m+ wide with a -0.1 –to 0 batter, offset 1.4 m from the edge of the wharf.

Wall Face: 70% chinked. Construction: Bearing and slope good condition on top and fair condition on bottom. Seafloor consists of gravel and boulders.

General Notes: - Spillage and fractures in rocks - Rock projecting at top of wall

N2 N3

CBCL Limited Killam’s Wharf Assessment Final Report 5

5-8

Dimensions: 3.5 m high X 1 m+ wide with a 0 batter, offset 1.3 m from the edge of the wharf.

Wall Face: 50% chinked. Construction: Good bearing on the top and poor on the bottom, fair slope and granular rock bottom.

General Notes: - Fractured rock and a lot of flat rocks

N1

WEST SEGMENT

8-11

Dimensions: 4 m high x 1.2 m+ wide with a 0.1 to 0.25 batter, offset 3.2 m from the edge of the wharf.

Wall Face: 3m high vertical seam, 1.8 m from the corner (at pile 9). 60% chinked

Construction: Bearing and slope both fair – many rocks tipped toward face. 200 mm sediment on granular bottom.

General Notes: - Old timber pile trapped behind bearing pile - Some fractured rocks - 2.5 m long rock on top

W1

11-13

Dimensions: 4.2 m high x 0.9m wide with a 0.2 to 0.3 batter, offset 3.3 m from the edge of the wharf.

Wall Face: 60% chinked. Construction: Fair slope and fair-good bearing. 100 mm sediment on granular bottom.

General Notes: - Fractured rock - Rocks cantilevered out at top of wall - Top rocks appear to be concrete debris - 20% of rocks with bearing surface tipped toward

the face

W2

13-17

Dimensions: 3.7-4.3 m high x 1.1 m wide with a 0.1 to 0.2 batter, offset 2.9 m from the edge of the wharf.

Wall Face: 50% chinked. Construction: Poor –fair bearing, slope is poor – good on the top and fair on the bottom. Sediment overlaying granular bottom.

General Notes: - Rocks protruding from face - Fractured rocks - 2 m³ spillage from piles 14-16

W4

17-21

Dimensions: 4.2 m high and 1.2 m wide with a 0 to 0.2 batter, offset 2.3 m from the edge of the wharf.

Wall Face: 3 m high vertical seam between piles 18 and 19, and 60% chinked.

Construction: Bearing and slope both fair, debris and rock sloughed in front of wall, void at top between piles 20-21

W6

General Notes: - Fractured rocks near bottom of wall

CBCL Limited Killam’s Wharf Assessment Final Report 6

SOUTH SEGMENT

21-25

Dimensions: 2.8-3.1 m high x 1.5 m wide with -0.2 to +0.25 batter, offset 0.8 m from the edge of the wharf.

Wall Face: 2m vertical seam at pile 24 and 40% chinked. Construction: Bearing and slope both fair, 25% tipped towards face, rocky bottom in front of wall.

General Notes: - A lot of voids around corner - Void in wall near Pile 23 - Corner unstable (around pile 21) - Flat rock - Fractured rocks - Negative batter on corner- rock protruding - Rock jammed against pile 25

S2

S3

25-28

Dimensions: 2.6-3 m high x 1 m wide with a 0.1 batter, offset 1 m offset from the edge of the wharf.

Wall Face: 70% chinked. Construction: Bearing and slope both fair-good, rock bottom General Notes:

- Spillage on bottom - Concrete slab piece on top of rock wall at pile 27

and 28 with old rebar - Fractured rocks - Abandoned timber stuck between piles 26 and 27 - Pile 28 has a steel casing

3.1.1 General Observations • Settlement of 0.2 m observed at the southwest corner where the slab on grade abuts the timber

apron. This appears to be due to the settlement of the backfill under the concrete wall. However, there is no apparent distress in the concrete wall. It appears to be continuously supported with no major cracks noticed.

• There is one significant area of sloughing near the southwest corner of the rock wall, opposite Piles 20-21. However, the most noticeable area of rock debris (spillage?) is in the vicinity of Pile 15.

• High tide typically overtops the rock wall. • The concrete wall is founded on backfill which has bagged concrete in front. The bagged concrete

appears to have been added later. There is a 0.3 m to 0.5 m difference in height retained by the bagged concrete.

• Photos taken during the site visit on August 23, 2016 by CBCL were compared with photos provided by the Town of Yarmouth. Approximately 16 locations were identified where recent photos could be compared with previous photos. Typically, no visible changes could be determined. There was only one location – the sloughed area opposite Piles 20-21 – where there appeared to be some loss of small rocks.

• Many rocks used in the rock wall are sedimentary and show obvious bedding planes and/or fracture.

• The batter on the rock wall face varies considerably from about -0.2 (worst case) to +0.3. It is even tipped the wrong way near the two rock wall corners.

CBCL Limited Killam’s Wharf Assessment Final Report 7

• The rock wall construction is quite irregular, with regard to bearing contact between rocks. The transverse slope of the bearing plane is occasionally tipped towards the face of wall, and there are often elongated rocks used.

• Some concrete debris has been placed apparently as part of the top of the south segment of wall. • There are occasional rocks projecting from the face of wall, and apparently moved, noticeably at

the top of wall.

CBCL Limited Killam’s Wharf Assessment Final Report 8

CHAPTER 4 RECOMMENDATIONS Based on the results of the preceding condition assessment, and the report by exp. Services Inc. (see Appendix A), the rockery wall notes that the wall does not meet current design guidelines. It is recommended that, in the near term, a displacement monitoring program be put in place, while a permanent long term solution is investigated. The following sections outline what a short term monitoring program would involve as well as two potential long term stabilization options. 4.1 Short Term Displacement Monitoring Program A displacement monitoring program could include the following: • Establish precise survey locations of selected points on the rockery wall, concrete retaining wall,

timber piles and concrete slab on grade; • Determine a series of measurements between the rock wall and adjacent “stable” points e.g.

timber piles; • Representative photographs taken at similar locations to detect any changes in the wall; • Follow up survey would be taken, say, approximately every 4 months, in order to assess whether

there is any displacement happening and at what rate it may be occurring at; and • Nominal visual inspection at monthly intervals during low tide to any obvious problem areas. The monitoring program would provide information on the safety of the wharf in its current condition, and an indication of how long the wharf could remain in service before a long term stabilization solution is required. 4.2 Long Term Stabilization Solutions Two stabilization options were developed as part of this study. The options provide different functional advantages and disadvantages. Some of the factors considered during this study include: • Maintaining the existing site layout, soil type, depth to bedrock and costs; • A description of each proposed layout, provided in the following sections; and • Concept drawings are provided in Appendix B. 4.2.1 Option 1 – New Rock Slope with Wharf Extension A new rock slope of armour stone would be extended out from the existing rockery wall (see drawing S03). The new rock slope would act to stabilize the existing rockery wall, and increase the capacity of the wall to resist surcharge loads from the wharf deck. A disadvantage of this option is that the rock slope would decrease the depth of water at the face of the existing wharf. At the north and south faces this should not affect the use of the wharf as these areas are not used for berthing boats. However, the west face of the wharf would have to be extended into the harbour in order to maintain the existing water depth. The extension of the wharf face would likely be in the order of 5 metres. New timber piles would be installed along with a new timber wharf deck. The location of floats for

CBCL Limited Killam’s Wharf Assessment Final Report 9

the marina would need to be adjusted accordingly. Further geotechnical investigation is required in order to determine design details of the wharf extension due to the unknown condition of the soil adjacent to the existing rockery wall. 4.2.2 Option 2 – New Sheet Pile Stabilization A new sheet pile wall would be placed in front of the existing timber piles (see drawing S04). The top of the sheet piles would be anchored to a concrete dead man located below the slab on grade area of the wharf. The area between the rock wall and sheet pile would be backfilled. The existing wharf deck as well as the concrete slab on grade would need to be removed to install the sheet pile anchors. A new concrete slab would be reinstated up to the edge of the sheet pile wall. The main advantage of this option is that it would maintain the existing site layout. However this option is more expensive than Option 1. The feasibility of installing sheet pile depends on the type of soil and the depth to bedrock. Further geotechnical investigations are required in order to determine whether the existing soil is appropriate for sheet pile construction.

CBCL Limited Killam’s Wharf Assessment Final Report 10

CHAPTER 5 OPINION OF PROBABLE COST

An opinion of probable cost, including contingencies, for each option is listed below. A more detailed breakdown of this opinion of probable cost is provided in Appendix C of this report.

This Class “D” opinion of probable cost is an order of magnitude conceptual budget used to screen and compare the alternate layouts presented in this report. It is not advisable to set upset limits for capital project budgets based on this level of cost estimate.

DESCRIPTION COST

(TAXES NOT INCLUDED) Short Term Monitoring of Settlement $15,000 Option 1 – New Rock Slope with Wharf Extension $469,000 Option 2 – Sheet Pile Stabilization $925,000

This opinion of probable costs is presented on the basis of experience, qualifications, and best judgement. It has been prepared in accordance with acceptable principles and practices. Market trends, non-competitive bidding situations, unforeseen labour and material adjustments and the like are beyond the control of CBCL Limited. As such we cannot warrant or guarantee that actual costs will not vary from the opinion provided.

5.1 Closure We trust this report outlines the project to your needs. Please contact the undersigned if you wish to discuss this report.

Prepared by: Reviewed by: Paul Hamson, EIT Greg Peters, M.A.Sc., P.Eng., P.E.

This document was prepared for the party indicated herein. The material and information in the document reflects CBCL Limited’s opinion and best judgment based on the information available at the time of preparation. Any use of this document or reliance on its content by third parties is the responsibility of the third party. CBCL Limited accepts no responsibility for any damages suffered as a result of third party use of this document.

CBCL Limited Appendices

APPENDIX A

exp. Services Inc. Report

7071 Bayers Road, Suite 2002, Halifax, NS B3L 2C2, Canada T: +1.902.453.5555 F: +1.902.429.5457 www.exp.com

November 09, 2016 HFX-00235194-A0/60.2 Mr. Greg Peters, P.Eng. CBCL Limited 1489 Hollis Street PO Box 606 Halifax, NS B3J 2R7 Re: Killam Wharf Retaining Wall Letter Report - Geotechnical Review Greg: This report summarizes the results of our geotechnical review of the stone retaining wall (rockery wall) supporting a portion of the Killam Wharf boardwalk and pavilion area. The site is located near 90 Water Street in Yarmouth, Nova Scotia. The purpose of the current review was to investigate the sub-surface conditions in the vicinity of the rockery wall and associated concrete curb wall, where accessible, and to assist in a preliminary assessment of the stability of the wall arrangement. 1.0 SITE DESCRIPTION & INVESTIGATION PROCEDURES The wharf and boardwalk area house wooden gazebo and platform structures, a large flag pole, and a small marine fueling station. The Killam Brothers Shipping Office is located east of the wharf, and Rudders Seafood Restaurant & Brew Pub is located north of the wharf. The perimeter of the boardwalk and pavilion area is bound on three sides by wooden deck, which surrounds a central concrete slab with a wooden platform and gazebo. The general arrangement is shown on CBCL drawing S01, attached. The concrete slab area is grade-supported. The wooden deck is suspended, and supported by beams spanning between the wharf’s timber piles and a concrete curb wall. The concrete curb wall follows the inside edge of the three-sided perimeter deck area. The concrete curb wall is founded on fill, that is being retained by a historic rockery wall. The rockery wall occupies a slightly larger footprint than the concrete curb wall. The concrete curb wall also acts to retain fill over its approximately 1 m height, beneath the concrete slab area. Small annular spaces are present between the wharf’s vertical timber piles and the outside face of the rockery wall. Our field review was conducted on August 23, 2016. A test trench was excavated under the supervision of an exp engineer who logged the sub-surface stratigraphy and collected representative soil samples. The investigation was carried out using a CAT 303.5E mini track excavator, supplied and operated by the Town of Yarmouth. A portion of the concrete slab was removed, then the test trench was advanced to a depth of 1.1 m below grade, exposing the base of the concrete curb wall. The test trench was refused at this depth on a cobble and boulder fill.

S01

TP-01

CBCL Limited Killam Wharf Retaining Wall Geotechnical Review

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The test pit location was selected to provide subsurface information in the general vicinity behind the concrete wall, and to minimize disturbance to the concrete panels. Test Pit TP-01 was located at the northwestern corner of the wharf. The test pit locations and general site arrangement are shown on the attached Figure S01. The elevation of the ground surface at the test pit location was estimated using information on the general arrangement figure. 2.0 SUBSURFACE CONDITIONS The general soil stratigraphy encountered immediately behind the concrete curb wall consisted of the following:

Concrete deck panels Granular Fill (approximately 0.5 m in thickness) Silty Sand Fill – (Silt with Sand to Silty Sand) Cobbles and Boulders

Under the Unified Soil Classification System, the upper granular fill was classified as ‘Poorly Graded Gravel with Silt and Sand (GP-GM)’. The lower silty sand fill was classified as ‘Silty Sand with Gravel (SM)’. The surficial fill was loose, dry, and brown in colour. The lower fill layer was compact, damp to moist, and dark brown in colour. The test pit was terminated upon refusal on a cobble and boulder fill that is being retained by the rockery wall. The maximum nominal diameter of boulders exposed at the base of the test pit was approximately 0.75 m. Groundwater was not encountered in the test pit during the investigation. However, the base of the concrete wall appears to be within the range of tides and wave action, so groundwater levels likely fluctuate continuously in the coarse fill. Groundwater conditions are also subject to seasonally effects and variations in response to recent precipitation events. In the test trench, it was observed that a geotechnical fabric lined the inside of the concrete wall, acting as a separator between the concrete wall and backfill. Laboratory test results and a detailed test pit log are provided in Appendix 1. 3.0 DISCUSSION AND RECOMMENDATIONS 3.1 Existing Conditions The following key observations of potentially problematic conditions were noted during our review of the existing wall arrangement. Tide and wave levels regularly inundate the rockery wall and reach the elevation of the concrete curb wall. The loss of soils from tide and wave action has caused undermining at the base of the concrete curb wall. Recent repairs have reportedly included placing sand bags at the base of the concrete curb wall and grouting to stabilize the soils. Some timber bracing connecting the base of the piling to the beams supporting the suspended deck are bowed and broken in various locations. This suggests that movements have occurred since the bracing was constructed, and that the beams and concrete curb wall have likely experienced settlement.

CBCL Limited Killam Wharf Retaining Wall Geotechnical Review

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Movements to date are not well-characterized but have occurred since construction was undertaken in the 1990s. Batter of the existing wall is near vertical, and slightly negative (toe set back from top) in some locations. The design batter on rockery walls is nearly always positive, typically ranging from 1H:6V to 1H:4V. This suggests that the front face of the rockery wall has rotated forward. It is likely that the rotation of the wall is related to the settlement noted above, and suggests that the concrete curb wall may be experiencing a punching failure (bearing pressure in excess of available SLS/ULS bearing resistance). The concrete perimeter wall at the top of the rock wall is not exhibiting obvious signs of distress that would suggest it has experienced differential movements. Settlements appear to be relatively uniform, or the differential component has been insufficient to cause cracking in the concrete. Local sloughing of stones has occurred near the southwest corner of the rockery wall. A void is present in the area of pile 23. It is not clear if the sloughing and presence of the void are a result of wave action, movement of the rockery wall, or a combination of both. 3.2 Rockery Wall Design Considerations Rockery walls have been used as retaining structures for millennia, however, formal design practices for these walls only became the norm in modern times, during the 1960s and 1970s. The date of construction of the rockery wall supporting Killam Wharf is not known, but predates the construction of the current wharf and boardwalk facility. We have reviewed modern rockery wall design standards and construction practices, and compared to information available for the Killam Wharf rockery wall. We noted that several conditions related to the Killam Wharf rockery structure don’t meet rockery wall design guidelines, summarized below. The concrete curb wall carries tributary loads from the wooden and concrete deck areas, and applies a surcharge load at the top of the rockery wall, near the seaward edge. The use of rockery walls to resist surcharge loads is not typical. The dimensions of the wall and ratio of height to width cannot be established with certainty without undermining the existing structure. However, the dimensions of the stones in the facing course of the wall appear insufficient to meet current accepted design guidelines, to provide an adequate factor of safety against overturning. Given the height of the wall, the base stones should be in the order of 2 m wide/deep, and the stones at the top of the wall should be at least 1.2 m wide/deep. The stones comprising the existing rockery wall are substantial, but do not meet these dimensional requirements. As discussed above, rockery walls are designed and constructed with positive batter (top set back from toe) for overturning stability. An overturning failure is likely in the long-term if mitigative measures not undertaken. Typical design batter for wall heights exceeding 1.5 m are positive, and in the range of 1H:6V to 1H:4V. The current batter of the Killam Wharf wall is near vertical, with local overhanging stones creating a negative batter.

CBCL Limited Killam Wharf Retaining Wall Geotechnical Review

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Rockery walls are generally not intended to resist significant loading from wave action. It is possible that this wall was originally reinforced or acting in conjunction with cribbing. The remnants of small timber piles are visible in some locations, which we presume to be part of this former structure. 3.3 Potential Wall Stabilization Approaches The current wall arrangement exhibits signs of distress and does not to meet modern design standards. The rockery structure is at risk of failure in the future. Although the movements experienced to date appear to be slow, accurately predicting the time to failure is not possible. As settlement occurs, and factors of safety for overturning are diminished, the potential for unexpected overturning failure is magnified. We recommend that consideration be given to both short-term and long-term fixes. Periodic monitoring for movements and settlement of the walls could be undertaken in the short-term, while permanent solutions for repair or reconstruction are considered. Limiting loading on the wooden boardwalk and eastern edge of concrete deck could also be considered, although a quantitative assessment of acceptable loading is not possible with the available information. Short term repairs could include repair of the local rock sloughs, and in-filling of the void area in the wall to prevent the possibility of progressive failure working back to more critical areas supporting the concrete curb wall. Consideration should also be given to replacing the broken and buckled bracing in the short term. The installation of additional bracing could also be considered, pending review by structural designers. We understand that the current stabilization concept includes placing armour stone around the perimeter of the rockery wall. The armour stone would splay outside the existing timber piles, requiring an extension of the marginal deck section. An additional row of timber piles would be driven to accommodate the extended deck section, and the existing floating wharf would be relocated adjacent the new marginal wharf face. We anticipate that the proposed stabilization concept is a viable long-term repair approach for the wharf and boardwalk area. In order to determine the extent and slope of the armour stone, additional analyses are required to determine configurations with an acceptable factor of safety for long term global stability. There is insufficient information to perform the analyses at this time. Boreholes will be required to determine the subsurface conditions at depth in the vicinity of the rockery wall and area of armour stone and pile construction. Other potential long term solutions for stabilizing the existing wall arrangement could include:

Constructing an independent retaining structure surrounding the existing rockery wall. Soldier piles with lagging or driven SSP may be viable solutions.

The installation of micropiles or driven piles to support the existing concrete curb wall independently from the underlying rockery wall.

Removal of the wooden deck and eastern section of the concrete deck area to allow complete reconstruction of the existing wall arrangement. Reconstruction could take a number of forms, including new cast in place concrete retaining structure, segmental concrete block retaining structure or a completely pile supported wharf and boardwalk with new armoured slope.

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4.0 LIMITATIONS AND CLOSURE The comments and recommendations given above are provided in accordance with our present understanding and available information for Killam Wharf. We trust that this information satisfies your current requirements. If you have any questions, or require additional information please contact us. Sincerely, Jamie Harper, P.Eng. Brian Walker, M.Eng., P.Eng. Geotechnical Engineer Senior Geotechnical Engineer exp Services Inc.

Appendix 1 – Geotechnical Laboratory Test Results Test Pit Log

0

10

20

30

40

50

60

70

80

90

100

0.001 0.01 0.1 1 10 100

#200 #100 #60 #40 #10

SAMPLE D10D30D60 %Gravel %Sand %Fines

71.52

DEPTH( m)

DEPTH( m)

TP-01

TP-01

Fill

Fill

SAND

fine coarse coarse

GRAVELCOBBLES

U.S. SIEVE NUMBERS

LL Cu

SILT OR CLAYmedium fine

HYDROMETER U.S. SIEVE OPENING IN INCHES

PERCENT

FINER

BY

WEIGHT

GRAIN SIZE IN MILLIMETERS

GRAIN SIZE DISTRIBUTION

#20 #4 3/8" 3/4" 1.5" 6"3"

PISAMPLE Classification (USCS) PLWC% Cc

TEST PIT

TEST PIT

TP-01

TP-01

4.3

7.9

4.04

BK - 1

BK - 2

0.4

0.8

0.4

0.8

BK - 1

BK - 2

Soil Deposit

POORLY GRADED GRAVEL with SILT and SAND GP-GM

SILTY SAND with GRAVEL SM

38.3

47.7

7.5

15.7

1.886

0.259

0.1117.94

3.73

54.2

36.6

AD

I H

ALIF

AX

DO

UB

LE

GR

AIN

SIZ

E D

IST

R.

IW R

ev:

5/2

4/1

2 K

ILLA

M W

HA

RF

TP

LO

GS

.GP

J D

AT

A E

NT

RY

.GD

T 9

/22/1

6 P

rinte

d b

y:

harp

erj

LOCATION Killam Wharf, Yarmouth, NS

PROJECT No. HFX-00235194-A0

CLIENT CBCL Limitedt: +1.902.453.5555 | f: +1.902.453.6325

7071 Bayers Road, Suite 2002

Halifax, NS B3L 2C2

CANADA

http://www.exp.com

FILLPoorly Graded Gravel with Silt and Sand(GP-GM), loose, dry, brown.

FILLSilty Sand with Gravel (SM), compact, damp tomoist, dark brown.

Refusal on Cobbles and Boulders @ 1.1 mDepth.

5.4

4.9

BK

BK

1

2

DESCRIPTION

SAMPLES

OT

HE

RT

ES

TS

20 40 60 80

TEST PIT RECORD

Unconfined Compression Test

Water Content & Atterberg Limits

Undrained Shear Strength, kPa

10 20 30 40 50 60 70 80 90

Wp W Wl

5.9

DE

PT

H (

m)

t: +1.902.453.5555 | f: +1.902.453.6325

7071 Bayers Road, Suite 2002

Halifax, NS, B3L 2C2

Canada

http://www.exp.com

LOCATION Killam Wharf, Yarmouth, NS

CLIENT CBCL Limited

0

1

2

EL

EV

. (m

)PROJECT No. HFX-00235194-A0

TEST PIT No. TP-01

DATUM CVGDWATER LEVELDATES DUG Aug 23, 2016

GE

OT

EC

HN

ICA

L L

OG

Rev:

6/2

7/1

1 K

ILLA

M W

HA

RF

TP

LO

GS

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CBCL Limited Appendices

APPENDIX B

Drawings

S01

S02

S03

S04

CBCL Limited Appendices

APPENDIX C

Opinion of Probable Capital Costs

ESTIMATE OF PROBABLE CONSTRUCTION COSTDATE: November 15, 2016

CBCL FILE No.: 160235.00Town of Yarmouth PREPARED BY: PH/AT/BH/GP

DESCRIPTION: Class D

No. UNIT EST. QTY UNIT COST TOTAL

1.0 LS 50,000$

2.02.1 m3 150 50$ 8,000$2.2 m3 150 75$ 12,000$2.3 m3 430 90$ 39,000$

-$3.0 -$3.1 m2 196 240$ 48,000$3.2 Ea 12 5,000$ 60,000$3.3 m3 196 120$ 24,000$3.4 m 134 50$ 7,000$

-$4.04.1 LS 1 10,000$ 10,000$

258,000$

A 25% 65,000$B 10% 26,000$C 0% -D 0% -E 0% -

349,000$

F LS 1 30,000$ 30,000$G LS 1 30,000$ 30,000$H Benthic Habitat Survey & Permitting LS 1 30,000$ 20,000$I Bathymetric Survey LS 1 10,000$ 10,000$J 7% 25,000$

464,000$

Construction Contingency

CONTINGENCIES and ALLOWANCES

THIS OPINION OF PROBABLE COSTS IS PRESENTED ON THE BASIS OF EXPERIENCE, QUALIFICATIONS, AND BEST JUDGEMENT. IT HAS BEEN PREPARED IN ACCORDANCEWITH ACCEPTABLE PRINCIPLES AND PRACTICES. MARKET TRENDS, NON-COMPETITIVE BIDDING SITUATIONS, UNFORSEEN LABOUR AND MATERIAL ADJUSTMENTS ANDTHE LIKE ARE BEYOND THE CONTROL OF CBCL LIMITED. AS SUCH WE CANNOT WARRANT OR GUARANTEE THAT ACTUAL COSTS WILL NOT VARY FROM THE OPINIONPROVIDED.

TOTAL CONSTRUCTION COST without HST1

Estimated Engineering Fees & ExpensesGeotechnical Investigation

TOTAL CONSTRUCTION & ENGINEERING COST without HST1

Escalation / Inflation

Engineering Design

Construction Services

Design Development Contingency

Location Factor Weather Allowance

Rock SlopeCore StoneFilter Stone800 Thick Armour Stone

Killam Wharf Assessment

Option 1 - Rock Slope

DESCRIPTIONContractor Costs

Mob and Demob

TOTAL CONSTRUCTION COST (Excluding Contingencies and Allowances)1

Timber Bents

Timber PilesTimber Sheathing

Timber Wharf ExtensionTimber Wharf Deck Extension

Relocate Existing FloatRelocate Existing Float

ESTIMATE OF PROBABLE CONSTRUCTION COSTDATE: November 15, 2016

CBCL FILE No.: 160235.00Town of Yarmouth PREPARED BY: PH/AT/BH/GP

DESCRIPTION: Class D

No. UNIT EST. QTY UNIT COST TOTAL

1.0 LS 1 50,000$ 50,000$

2.02.1 kg 71,456 5$ 322,000$2.3 Ea 34 3,000$ 102,000$

-$3.0 -$3.1 Ea. 503 30$ 16,000$3.2 m2 352 15$ 6,000$

-$4.0 -$4.1 m3 1,100 30$ 33,000$4.2 m3 1,000 10$ 10,000$

-$5.0 -$

5.1 m3 130 500$ 65,000$-$

5.0 -$

5.1 LS 1 10,000$ 10,000$

614,000$

A 25% 154,000$B 10% 62,000$C 0% -D 0% -E 0% -

830,000$

F LS 1 30,000$ 30,000$G LS 1 30,000$ 30,000$H Benthic Habitat Survey & Permitting LS 1 30,000$ 20,000$I Bathymetric Survey LS 1 10,000$ 10,000$J 7% 5,000$

925,000$Construction Services

TOTAL CONSTRUCTION & ENGINEERING COST without HST1

Estimated Engineering Fees & ExpensesGeotechnical InvestigationEngineering Design

THIS OPINION OF PROBABLE COSTS IS PRESENTED ON THE BASIS OF EXPERIENCE, QUALIFICATIONS, AND BEST JUDGEMENT. IT HAS BEEN PREPARED IN ACCORDANCEWITH ACCEPTABLE PRINCIPLES AND PRACTICES. MARKET TRENDS, NON-COMPETITIVE BIDDING SITUATIONS, UNFORSEEN LABOUR AND MATERIAL ADJUSTMENTS ANDTHE LIKE ARE BEYOND THE CONTROL OF CBCL LIMITED. AS SUCH WE CANNOT WARRANT OR GUARANTEE THAT ACTUAL COSTS WILL NOT VARY FROM THE OPINIONPROVIDED.

TOTAL CONSTRUCTION COST (Excluding Contingencies and Allowances)

CONTINGENCIES and ALLOWANCES Design Development Contingency Construction Contingency Escalation / Inflation Location Factor Weather Allowance

TOTAL CONSTRUCTION COST without HST

Relocate Floating Dock TemporarilyRelocate Floating Dock Temporarily

FillStructural Fill Behind Sheet Piles

Remove existing timber wharf deck

Concrete Slab on GradeConcrete Slab on Grade

DemolitionRemove existing concrete slab on grade

Killam Wharf Assessment

Option 2 - Sheet Pile Wall

DESCRIPTIONContractor Costs

Mob and Demob

AZ28 Sheet PilesAZ28 Sheet PilesConcrete Anchors c/w Tie Back

Common Fill For Slab on Grade