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INCORPORATED VILLAGE OF SALTAIRE

Engineering Study For The

Saltaire Terminal

in

Bay Shore

 

Prepared for:

Incorporated Village of Saltaire

P.O. Box 5551

Bay Shore, New York 11706

 

 

January 2002

 

Prepared by:

 

 

Cashin Associates, P.C.

Engineering •Planning •Construction Management

1200 Veterans Memorial Highway, Hauppauge, New York 11788 - (631) 348 - 7600

601 Brickell Key Drive, Suite 606, Miami, Florida 33131 - (305) 579 - 2006

TABLE OF CONTENTS

INCORPORATED VILLAGE OF SALTAIRE

ENGINEERING STUDY

OF THE

SALTAIRE TERMINAL

IN BAY SHORE, NEW YORK

 

SECTION 1 INTRODUCTION 1

SECTION 2 SITE DESCRIPTION AND HISTORY 1

SECTION 3 EVALUATION OF CURRENT CONDITIONS 2

SECTION 4 RECOMMENDATIONS 3

4.1 Safety Concerns 4

4.2 Utilities 4

SECTION 5 ALTERNATIVE BULKHEAD CONSTRUCTION AND MATERIALS 4

5.1 Steel 5

5.2 Vinyl 5

5.3 Fiber Reinforced Polymer Composite 5

5.4 Timber 6

5.5 Recommendations 6

SECTION 6 PRELIMINARY COST ESTIMATES 7

SECTION 7 CONCLUSIONS 7

EXHIBITS

E-1 Bulkhead Layout Existing Conditions (Not on Website)

APPENDICES

APPENDIX A Site Photographs (Not on Website)

APPENDIX B Preliminary Construction Cost Estimates

 

 

SALTAIRE TERMINAL

BAY SHORE, NEW YORK

BULKHEAD ASSESSMENT

January 7, 2002

 

1.0 INTRODUCTION

This report outlines the findings of an investigation of the Village of Saltaire Terminal in Bay Shore, NY. The purpose of the investigation was to inspect the ferry terminal facility and bulkhead, specifically the tierod and deadman system that supports the bulkhead, and determine a method of repair or replacement of the bulkhead system. Cashin Associates, P.C. (CA) visited the site, reviewed an original site plan, interviewed a dock builder present during the prior reconstruction in the 1980’s, and a representative of the ferry operator. CA has included in this report: a site description and history, evaluation of current conditions, review of potential construction alternatives, materials for replacement and/or repair of the bulkhead, cost estimates of the alternatives, and identification of safety concerns that need to be addressed immediately.

  1. SITE DESCRIPTION AND HISTORY
  2. The ferry terminal bulkhead is currently constructed with 12" dia. CCA-treated timber soldier piles and CCA-treated 3" x 10" timber sheathing. The west and south-east bulkheads are constructed as smooth face bulkheads where the wales and soldier piles are not exposed. The smooth face bulkheads have visible tierod bolts. One located near the top of the bulkhead and a second at apparent low water indicating walers located behind the bulkhead at these locations. The north, east, and south-west bulkheads are Navy Style construction with both the wales and the timber piles exposed. On the Navy Style bulkhead there are exposed wales at two locations. One location near the top of the bulkhead and a second at apparent low water. Soldier piles are located along the exposed side of the entire length of bulkhead spaced at unequal distances as shown in Exhibit E-1. The depth to soil, on the water side, from the top of the bulkhead ranges from 8’ on the eastern most end to 13.5’ adjacent to the ferry terminal building. The ferry docks against the west bulkhead where passengers board and exit at the one-story, open-frame construction, ferry terminal building.

    CA interviewed Mr. Ed Mooney from the Fire Island Ferry Terminals and Mr. Bob Conway from Ronback Marine Construction. Mr. Mooney provided CA with a copy of the original terminal layout plan date November 1, 1977. This original plan is the only construction documentation that was provided to CA. Mr. Mooney stated that the ferry terminal had been modified from the original layout to reduce the size of the actual ferry terminal basin so that the parking area could be expanded to accommodate more vehicles. As-built plans or construction details of this reconstruction have not been located by the Village or Fire Island Ferry Terminals. Mr. Conway, who worked for the reconstruction contractor during this period, stated that this reconstruction was done in the early 1980’s. According to both sources, a double dead-man system on the north back bulkhead of the terminal was installed at this time as shown in Exhibit E-1. The other bulkhead segments also have tierods although they are reportedly single deadman systems. The timber sheets are reported to be twenty-four feet in length, according to these sources. It is no longer known if the original bulkhead was removed during reconstruction. Soldier piles were observed on both sides of the existing bulkhead. Mr. Conway believes that the original bulkhead may be buried behind the existing bulkhead, which would explain the piles on both sides of the bulkhead.

  3. EVALUATION OF CURRENT CONDITIONS
  4. CA met with Mr. Mooney and conducted a site visit on October 22, 2001. The general layout of the parking lot and conditions of bulkhead are as shown in Exhibit E-1. Two test pits were excavated prior to this visit and were still exposed for CA’s inspection. The test pits are shown in Photos 1, 2, and 3 in Appendix A. The test pits were excavated to visibly examine the condition of the tierods, the extent of deterioration of CCA sheathing due to marine borer activity and the wash out of backfill material behind the bulkhead that is causing undermining and settlement of asphalt paving in the adjacent parking area. CA also inspected all visible portions of the bulkhead.

    The first test pit excavated on the southwest corner of the bulkhead extended 11.5’ back from the south-west face and 14.8’ back from the west face. The maximum depth of the test pit was sixteen inches that exposed only the top tierod. This tierod was observed to be in satisfactory condition. The lower tierod was not unearthed so an assessment of its condition can not be made.

    The second test pit was excavated along the north bulkhead just east of the floating dock that extends into the basin. The test pit was excavated twenty-one feet back from the face of the bulkhead and seven feet wide. The maximum depth of this test pit was 2.9’ below the pavement surface. The tops of the timber deadmen were exposed. The deadmen were both saturated as they are in the tidal range. The upper tie-rod appeared to be in satisfactory condition. The soil fill in this area was uniformly graded sand. The lower deadman system was not exposed. The north bulkhead has a double deadman system. A second line of deadman are located approximately forty three feet back from the north face of the bulkhead. These are identified by evenly spaced 19" square heaves, spaced at 9.5’ on center (Photo 4). These deadman were not unearthed for condition inspection.

    The timber sheathing is in a deteriorated condition with open holes in the sheathing that allow the flow of backfill soil through the sheathing causing significant sinkholes in back of the bulkhead as shown in Photos 5 and 6. There is a defined deformation line in the asphalt parking lot on the north-east side of the ferry terminal where the pavement has settled (See Photo 11). The deformation line runs parallel to the bulkhead, located 18.5’ behind the bulkhead, and is most likely due to settlement of the deadman system.

    The condition of the easternmost bulkhead could not be assessed at the time of the visit. A fence located just behind the bulkhead, and a deck on top belonging to the adjacent marina prevents access (See Photo 10). Mr. Mooney stated this bulkhead was constructed at the same time as the other bulkheads in the ferry terminal, the condition of this bulkhead is assumed to be similar. There are no apparent sinkholes behind this segment of bulkhead.

  5. RECOMMENDATIONS

Based on the review of available site information and subsequent inspection and analysis, CA has determined that the existing bulkhead is in a severely deteriorated state and requires repair or renovation. The first construction alternative is the installation of a new bulkhead system including new tierods and deadmen that would be constructed outboard of the existing bulkhead. CA recommends that the top three feet of existing bulkhead, tierods and deadmen, from the face of the bulkhead to the extent of the deadmen be removed in the parking lot and replaced with soil that can be thoroughly compacted. The parking lot can then be regraded to the existing low point and the drainage pattern reestablished. This will level the parking lot and prevent significant future settlement. The eastern-most bulkhead adjacent to the marina also should be renovated with a new bulkhead and tie back system. As above, the new bulkhead would be constructed within eighteen inches of the existing bulkhead.

The second construction alternative would be to simply resheath the exiting bulkhead and attach it to the existing sheathing thereby utilizing the existing tie-backs and deadmen. This option would provide a quick fix to the deterioration problems and reduce further sinkholes from developing if the space between the two bulkheads was filled with soil. However due to the age of the existing system this alternative may not provide a long-term solution. CA recommends that this alternative also include the parking lot recommendations discussed above. Adequate compaction of the fill will be difficult with the existing tierods and deadmen in place.

It is CA’s opinion that the most efficient means of renovation would be to construct a new bulkhead system including new bulkhead, tierods, and deadman as described in the first alternative. Because of the age and condition of the existing system, the new system would provide a longer service life. In addition, as described previously, removal of the existing bulkhead, tierods, and deadman material in the parking lot will allow the lot to be thoroughly re-compacted and leveled and reduce future settlement from consolidation of decaying timber material.

Construction of a new bulkhead outboard of the existing one on the eastern most end of the terminal which is common to the marina will require the coordination with the marina owners to remove and replace the existing fence and decks.

 

4.1 Safety Concerns

In accordance with the scope of work, CA investigated safety concerns in the area of the ferry terminal and bulkhead system. The first is that safety ladders should be installed, one per each length of bulkhead. Currently vehicles park directly in back of the bulkhead as shown in Photos 7, 8, 9, 10, and 11. Settlement and surcharge on the bulkhead is increased by the parking situation. Delineation of the parking to maintain a 5’ width in back of the bulkhead without vehicle parking would reduce the surcharge condition. CA recommends that the Village delineate an area from the face of the bulkhead to 5’ behind the bulkhead by either constructing a boardwalk or alternatively, installing guiderail. This area can be designated for pedestrian circulation, that would, in-turn, improve pedestrian/vehicular conflicts in the parking area. As discussed above the parking lot should be graded, repaved, and striped to accommodate the maximum number of automobiles.

 

4.2 Utilities

Existing utilities, such as water service and drainage outfall pipes, should be extended through to the proposed bulkhead system. Currently there are at least three 15" diameter concrete drainage outfall pipes that penetrate the existing bulkhead. These should be extended through the proposed sheathing.

CA observed that there is a water service attached to the front face of the bulkhead of the north side bulkhead within the basin area. CA recommends placing the existing water service so that it is buried behind the proposed bulkhead. This would protect it from weather damage and remove it from sight.

5.0 ALTERNATIVE BULKHEAD CONSTRUCTION AND MATERIALS

If the Village decides to construct a new bulkhead system there are two options for bulkhead construction; Smooth-Face or Navy Style. The existing bulkhead currently incorporates both types. CA recommends a Navy Style bulkhead that is easier to construct if a new bulkhead system with a new tierod and deadman system is selected.

If the Village elects to re-sheath the existing bulkhead both Navy Style, and Smooth-Face construction will be utilized to match the existing.

There are several different types of materials that can be used for the sheathing of either a new bulkhead or re-sheathing the existing bulkhead. CA investigated the following four; steel, vinyl, fiber-reinforced polymer composite and wood.

 

5.1 Steel

Steel is the strongest material of the four materials discussed. It is heavy and durable as shown by its strength rating in Table 1. For the purposes of this report Skyline Steel Corporation’s ARBED AZ13’s steel sheet piles were used as the basis for comparison with the alternative materials discussed The use of a material with the strength of the steel sheeting would not be cost effective for this application. Steel is greater than six times heavier than vinyl, construction is more intensive and additional manpower is required due to the weight of material. In comparison with the other materials discussed the equipment to install steel sheets would be more expensive. The sheets would must be installed with vibratory or drop hammer, while the other materials can be installed by partial jetting with hammer use only near termination. With only surcharge loading from vehicles it would not be cost effective in material and labor costs to consider steel for this application. Steel will rust with time which is not aesthetically pleasing. The service life of steel is dependent on the thickness of the steel, which corrodes at a rate of 3.94 x 10-3 inches per year in salt water.

5.2 Vinyl

There are several different manufacturers of vinyl sheet piles and each product varies in strength and material properties. For the purpose of this report CA selected Shore Guard 700 for comparison to other alternative materials. Vinyl is a lightweight material in comparison with steel and would require a lower energy hammer and fewer workers to install in a shorter amount of time. This material has low installation and maintenance costs, incorporates ultraviolet stabilizers to mitigate sun damage, and is corrosion resistant. With any vinyl material there is a concern with UV degradation with time. For this reason vinyl sheet piles are manufactured with Carbon Black to inhibit or retard UV degradation. The benefit of vinyl sheet piles, as with most other synthetic sheet piles, is that marine borers and most chemicals do not effect this material. Vinyl sheet piles have a high impact strength ranging from 13,000 to 15,000 psi, which is important if the marina is subject to ice floes. This material is available in several colors and has a 50 year material warranty.

5.3 Fiber Reinforced Polymer Composite

For this report, Super-Loc fiber reinforced polymer composite (FRP) sheet piles, manufactured by Creative Pultrusions, will be discussed as the representative fiber reinforced polymer composite. FRP has a thinner cross-section in comparison to vinyl sheets. It is manufactured by a pultrusion process that leaves fewer voids than found in vinyl and actually aligns the polymers into a stronger configuration which gives FRP stronger material properties than vinyl. This is shown in Table 1. FRP has a high strength-to-weight ratio and is corrosion resistant. As with vinyl, FRP is designed to be U.V. resistant to protect from damage due to sunlight. This material exhibits better creep resistance in comparison with vinyl and is a thermal set material that does not loose strength or become brittle in cold weather, as vinyl occasionally does. Due to its thin section this material requires installation with a lightweight vibratory hammer as the impact strength of FRP is not as high as vinyl. Impact strength of a material is an important consideration if the bulkhead will be subject to ice floe impacts. This material is available in several colors and has a 50-year material warranty.

5.4 Timber

Timber sheathing can be severely deteriorated by marine borers which destroy wood as seen on the existing wood sheathing. Timber sheathing realistically will last only 15 years depending on the level of marine borers activity in the water. The borers are relatively unaffected by the CCA in treated wood. The lumber suppliers stated that they can not obtain 3" x 10" x 24’ length seawall grade wood sheathing because of lack of the required size timbers for the length required. The combination of the inability to obtain the material along with the marine borer damage makes timber an unfeasible option for this project.

 

TABLE 1

VILLAGE OF SALTAIRE

FERRY TERMINAL

BAY SHORE, NEW YORK

BULKHEAD SHEETING MATERIALS

MATERIAL PROPERTY COMPARISONS

CHARACTERISTIC

UNITS

STEEL

VINYL

FIBER REINFORCED POLYMER

Strength Rating

FT-LB / FT.

50,000

10,667

11,267

Weight/Foot

POUNDS

48.38

8.00

4.70

Thickness

INCHES

0.375

0.450

0.200

Section Modulus

IN3/FT

24.20

40.00

7.96

Material Modulus

PSI

29,000,000

380,000

3,500,000

Tensile Strength

PSI

39,000

6,300

33,000

Design Strength

PSI

19500

3,200

16,500

Section Depth

INCHES

11.93

10.00

6.00

Section Width

INCHES

26.38

12.00

18.00

 

    1. Recommendations

As discussed above timber is not a feasible option for this marina. Steel is also not recommended by CA because of its high cost. Of the two remaining alternatives CA recommends the use of vinyl because of its impact strength, slightly lower cost and its history of successful use in the region. CA recommends the use of vinyl for either construction alternative selected.

 

 

6.0 PRELIMINARY COST ESTIMATES

CA contacted manufacturers and installers of each of different options discussed in the previous section. An engineer’s preliminary cost estimate which compares the different sheet material costs has been included in Appendix C. The estimate for Alternative 1 – Reconstruction of the bulkhead system includes, the sheet pile material costs, the Navy Style Construction. Also included in the estimate is: all work to stabilize the existing bulkhead, install a new deadman system, remove all the outboard soldier piles, construct a new bulkhead outboard of the existing one, install safety ladders, drainage extensions, a five foot boardwalk along the bulkhead and parking lot improvements. The construction cost for CA’s recommendation of vinyl sheet piles, Navy Style bulkhead system is $696,500.00

CA developed a cost for construction of Alternative #2. This alternative is for the resheathing of the existing bulkhead to include new vinyl sheet piles, new wales, new soldier piles, drainage extensions, a five foot boardwalk along the perimeter of the bulkhead, and parking lot improvements. The cost of this alternative would be approximately $605,500.00

 

  1. CONCLUSION

This report outlined the findings of an investigation of the Village of Saltaire Terminal in Bayshore, NY. The purpose of the investigation was to inspect the ferry terminal and bulkhead, specifically the tierods and deadmen that supports the bulkhead, and determine a recommended method of repair or replacement of the bulkhead system. After inspection of the bulkhead and parking lot area, CA recommends construction of a new bulkhead system outboard of the existing bulkhead utilizing Navy-Style construction and vinyl sheet piles. CA’s recommendation is based on providing the best value and longest life for the ferry terminal. This new system would include new tierods and deadmen, partial reconstruction of the parking area, as well as a five-foot wide timber boardwalk around the perimeter of the bulkhead to reduce loads on the new bulkhead and for pedestrian customer circulation and safety.

Based on the deteriorated conditions of the existing bulkhead and ongoing settlement in the parking lot, as well as the extended time period necessary to obtain New York State Department of Environmental Conservation and United States Army Corps of Engineers permits for this work, CA recommends that the Village adopt an expedited schedule to undertake the work necessary at the marina so as not to interfere with the summer season.

VILLAGE OF SALTAIRE
FERRY TERMINAL
BAY SHORE, NEW YORK
BULKHEAD SHEETING MATERIALS
PRELIMINARY CONSTRUCTION COST ESTIMATES
DECEMBER 14, 2001
    Unit Price      
Item Material Incl. Installation Unit Quantity Total
1A Steel (Alternate 1A) $60.00 S.F. 13,488 $809,280.00
           
1B Vinyl (Alternate 1B & 2) $25.80 SF 13,488 $347,990.40
           
1C Fiber Reinforced $27.00 SF 13,488 $364,176.00
  Polymer Composite (Alternate 1C)        
           
1D Marine Grade CCA Sheathing (Alt. 1D) N/A     N/A
           
2 10" x 10" Marine Grade CCA $9.00 BF 10,400 $93,600.00
  Treated Wales        
           
3 12" Class B Marine Grade $19.00 LF 3,300 $62,700.00
  CCA treated Timber Piles (L=24')        
           
4 CCA Treated Timber Decking $25.00 SF 2,750 $68,750.00
           
5 Concrete Pipe Extensions $21.00 LF 6 $126.00
           
6 Tie Backs $3.00 LB 7,400 $22,200.00
           
7 Dead Man System; 12" Class B Marine $19.00 LF 1,650 $31,350.00
  Grade CCA treated Timber Piles        
           
8 Excavation $3.50 CY 2,830 $9,905.00
           
9 Backfill Existing and New Sheeting $60.00 TONS 305 $18,300.00
           
10 Asphalt Parking Lot $60.00 TONS 500 $30,000.00
           
11 Asphalt -RCA $3.50 SY 2,830 $9,905.00
           
12 Safety Ladders $300.00 EA 5 $1,500.00
           
Alternate 1A       Total Cost for Steel Bulkhead System $1,157,616.00
Alternate 1B       Total Cost for Vinyl Bulkhead System $696,326.40
Alternate 1C       Total Cost for Fiber Reinforced Polymer Bulkhead System $712,512.00
           
Alternative No. 2       Total Cost for Vinyl Bulkhead Resheathing Only:  
        Does Not Incl. Tiebacks/Deadmen $605,156.40