A_-_26-05-ITB_-_Exhibit_A_-_Concha_Repair_Protocol_and_Performance_Specifications.pdf

City of Sebastian – Concha Water Control Structure Repairs

Repair Protocol and Performance Specifications

Prepared for:

City of Sebastian 1225 Main Street Sebastian, FL 32958

Prepared by:

Kimley-Horn and Associates, Inc.

200 Central Avenue, Suite 600 St. Petersburg, FL 33701

© Kimley-Horn and Associates, Inc.

Registry No. 35106 June 2025 St. Petersburg, Florida 148882006

This document, together with the concepts and designs presented herein, as an instrument of service, is intended only for the specific purposes and client for which it was prepared. Reuse of and improper reliance on this document without written authorization and adaptation by Kimley- Horn and Associates, Inc. shall be without liability to Kimley-Horn and Associates, Inc.

kimley-horn.com 200 Central Ave, Suite 600, St. Petersburg, Florida 33701 727 547 3999

SIGNATURE PAGE

This item has been digitally signed and sealed by Seth Schmid on the date adjacent to the seal.

Signature must be verified on any electronic copies.

Seth Schmid, PE

FL PE #54640

Kimley-Horn and Associates, Inc.

1800 Second Street Ste. 900 Sarasota, FL 34236

Table of Contents

1.0 BACKGROUND / LOCATION

2.0 GENERAL DESCRIPTION OF STRUCTURE

3.0 GENERAL SCOPE OF WORK

4.0 REPAIR PROTOCOL AND PERFORMANCE SPECIFICATIONS

4.1 Dewatering plan

4.2 Repair of Active Leak Below Weir Cap (refer to FIGURE 3 for location and FIGURE 4 for sketch of repair)

4.3 Repair of Active Leak at Sheet Pile Interlock (refer to FIGURE 5 for location and FIGURE 6 for sketch of repair)

4.4 Recoating Sheet Piles

4.5 General Notes

4.6 Shop Drawings and Other Submittals

4.7 Steel Notes

1.0 BACKGROUND / LOCATION

The Concha Water Control Structure (also known as the Elkcam Waterway Control Structure) is a notched weir structure located on the Elkcam Waterway in the City of Sebastian (Section 25, Township 31S, Range 38E). The structure is located in the southwestern portion of the City of Sebastian, between Concha Dr. and Joy Haven Dr. The structure controls flow from the City’s stormwater canal system to the St. Sebastian River, eventually outfalling into the Indian River Lagoon. The Concha Water Control Structure is maintained by the City of Sebastian (City) and is accessible via City owned lots on either side of the structure at 710 Concha Dr. and 577 Joy Haven Dr. The water control structure was previously reviewed in October 2024 for Civil, Structural and Underwater deficiencies.

FIGURE 1 shows the location of the Concha Water Control Structure on the Elkcam Waterway.

FIGURE 1: STRUCTURE LOCATION MAP

2.0 GENERAL DESCRIPTION OF STRUCTURE

The water control structure was constructed in 1999 and is approximately 175-feet long. Construction plans were acquired for the water control structure. The construction plans were for the Replacement of Elkcam Waterway Control Structure, prepared by Masteller & Moler, Inc. and dated August 19, 1999.

Based on a review of the construction plans and field measurements, the water control structure is constructed of steel sheet piles consistent with a PZC 13 profile and a 36-inch wide by 18-inch deep concrete cap on top. The existing steel sheet piling appears to have a coal tar epoxy applied to both sides (upstream and downstream). Plan and profile views of the structure are shown in FIGURE 2.

Concha Water Control Structure

City owned lots

FIGURE 2: CONTROL STRUCTURE PLAN AND PROFILE (COURTESY OF 1999 CONSTRUCTION

PLANS BY MASTELLER & MOLER)

3.0 GENERAL SCOPE OF WORK

The Project will consist of dewatering the work area on both sides (upstream and downstream) of the existing sheet pile water control structure and removing the existing sheet pile coating on both faces (upstream and downstream) along the entire length of the water control structure. Two active leaks in the steel sheet pile shall be repaired. Any additional areas on the steel sheet piling with significant section loss after removal of the coating and cleaning shall be repaired in the same manner as those areas with active leaks. One active leak near the existing concrete cap will require a portion of the cap to be chipped out and repaired to provide adequate clearance to install the sheet pile repair. Both sides of the steel sheet piling (upstream and downstream) shall be recoated along the entire length of the water control structure. Recoating shall extend from the underside of the existing concrete weir cap to the ground or mudline.

4.0 REPAIR PROTOCOL AND PERFORMANCE SPECIFICATIONS

4.1 Dewatering plan

The work area shall be dewatered so that all sheet pile repair and recoating work is performed in the dry.

The Contractor shall submit a dewatering plan to the Owner or Owner’s Representative for review and approval prior to the commencement of construction. The dewatering plan shall utilize systems such as bladder dams and bypass pumps that minimize the disturbance to the adjacent residential properties while maintaining flow in the waterway.

4.2 Repair of Active Leak Below Weir Cap (refer to FIGURE 3 for location and FIGURE 4 for sketch of repair)

Alternative equivalent concrete weir cap repair materials to those indicated below must be reviewed and approved by the Owner or Owner’s Representative and shall consist of a single manufacturer.

1. Chip out sufficient concrete on the underside of the existing weir cap in the vicinity of the hole in the steel sheet pile to allow installation of the repair plate and to repair the existing coating on the backside of the sheet pile damaged by the welding heat. Care should be taken to minimize the amount of concrete removed such that the depth of concrete removal does not exceed 3-inches.

The edges of the area of concrete removal should be saw cut perpendicular to the surface to a depth of at least ¼-inch into the substrate concrete or as required by the repair mortar manufacturer.

2. Abrasive blast clean both the upstream and downstream faces of the steel sheet piling in the vicinity of the repair in accordance with the Society for Protective Coatings Standard SSPC-SP10, Near White Metal Blast Cleaning to remove all existing coatings and corrosion and provide a minimum 1.5 mil angular anchor profile.

3. Place a 3/8-inch thick steel plate over the upstream side of the hole in the sheet pile and seal weld around the entire perimeter of the repair plate. Plate should extend a minimum of 3-inches beyond the sheet pile hole in each direction except for the portion that will be embedded in the pile cap (see FIGURE 4).

4. Clean the concrete surface to be repaired with Chlor Rid Salt Remover. Prime the area of steel sheet pile and steel repair to be covered by concrete cap repair mortar with Tnemec Series 1, or approved equivalent, in accordance with the manufacturer’s recommendations.

5. Prepare concrete surface and patch the concrete weir cap in the vicinity of the repair with Tnemec Mortarcrete Series 217, or approved equivalent, in accordance with the manufacturer’s recommendations. Use any primer or bonding agents on the concrete surface as recommended by the repair mortar manufacturer. Finish the repair flush with the adjacent existing concrete and cure concrete repair in accordance with manufacturer's recommendations.

6. Coat the portion of repair below the limits of the concrete weir cap, on both sides (upstream and downstream) of the sheet pile, in accordance with the sheet pile recoating protocol in Section 4.4.

FIGURE 3: LOCATION OF ACTIVE LEAK BELOW WEIR CAP

Approximate location of active leak below weir cap.

Existing steel sheet pile water control structure.

FIGURE 4: SKETCH OF CONCRETE WEIR CAP REPAIR.

4.3 Repair of Active Leak at Sheet Pile Interlock (refer to FIGURE 5 for location and FIGURE 6 for sketch of repair)

1. Abrasive blast clean both the upstream and downstream faces of the steel sheet piling in the vicinity of the repair in accordance with SSPC-SP10, Near White Metal Blast Cleaning to remove all existing coatings and corrosion and provide a minimum 1.5 mil angular anchor profile.

2. Place a 3/8-inch thick steel plate over the upstream side of the leak in the sheet pile interlock and seal weld around the entire perimeter of the repair plate. Plate should extend a minimum of 3-inches beyond hole / active leak in sheet pile interlock in each direction.

3. Coat the portion of repair on both faces of the sheet pile in accordance with the sheet pile recoating protocol in Section 4.4.

Existing steel sheet piling.

Existing concrete cap.

Existing steel sheet piling embedded in concrete cap.

Chip out sufficient concrete to allow installation of repair plate.

3/8-inch thick x 6-inch wide steel repair plate over hole in sheet pile.

Prime and patch with repair mortar after installation of steel repair plate in accordance with the repair protocol.

Approximate location of hole in steel sheet pile.

FIGURE 5: LOCATION OF ACTIVE LEAK AT SHEET PILE INTERLOCK

Approximate location of active leak at sheet pile interlock.

Existing steel sheet

FIGURE 6: LOCATION OF ACTIVE LEAK AT SHEET PILE INTERLOCK

4.4 Recoating Sheet Piles

The following coating system for the steel sheet piles of the water control structure was developed by Tnemec. Alternative equivalent coating systems must be reviewed and approved by the Owner or Owner’s Representative and shall include required surface preparation. Alternative equivalent coating systems shall consist of a single manufacturer.

The sheet pile coating system shall extend from the underside of the existing concrete weir cap to the ground or mudline on both sides (upstream and downstream) of the steel sheet piling for the entire length of the water control structure.

1. Surface preparation: Abrasive blast clean both the upstream and downstream faces of the steel sheet piling in accordance with SSPC-SP10, Near White Metal Blast Cleaning to remove all existing coatings and corrosion and provide a minimum 1.5 mil angular anchor profile.

2. Repair all active leaks indicated in the above Sections 4.2 and 4.3 repair protocol.

3. Repair all isolated areas of corrosion on the sheet pile face that have 20% or more section loss after blast cleaning (see FIGURE 7). Repair in accordance with the Active Leak at Sheet Pile Interlock protocol described in Section 4.3 above.

4. The first coat shall consist of Tnemec Series 90-97, 2.5 mils – 3.5 mils thick, applied to both the upstream and downstream faces of the steel sheet piling in accordance with the manufacturer's recommendations.

Existing steel sheet piling (plan view).

Existing sheet pile interlock with active leak.

3/8-inch thick x 7-inch wide steel repair plate over active leak in sheet pile interlock.

5. Use Tnemec Series 215 to fill angular pits and voids in the steel sheet piling that isn’t filled by the first coat.

6. The second coat shall consist of Tnemec Series 142, 16 mils – 20 mils thick, applied to both the upstream and downstream faces of the steel sheet piling in accordance with the manufacturer's recommendations.

7. The third coat shall consist of Tnemec Series 1094, 3 mils to 5 mils thick, applied to the UV-exposed areas above the waterline only on both the upstream and downstream faces of the steel sheet piling in accordance with the manufacturer's recommendations.

FIGURE 7: LOCATION OF TYPICAL AREA OF SIGNIFICANT CORROSION WITH POTENTIAL FOR

MORE THAN 20% SECTION LOSS AFTER CLEANING.

Isolated area of significant corrosion, typical along length of both faces of steel sheet piling.

Existing steel sheet

4.5 General Notes

1. The governing code for this project is the Florida Building Code, eighth edition (2023).

2. The contract documents have made no intent to give specific instructions concerning the means, methods, techniques, sequences, procedures and assignment of work.

3. The Contractor shall be solely responsible for supervising and directing the work.

4. Construction shall comply with the requirements of the governing building code and all other applicable federal, state and local codes, standards, regulations and laws.

5. The Contractor shall visit the project site and be familiar with the proposed work. The Contractor shall take field measurements and verify all field conditions and report any discrepancies to the Owner or Owner’s Representative prior to construction.

6. Discrepancies, omissions or variations noted on the repair protocol or in the specifications discovered by the Contractor during and after the bidding period shall be immediately communicated in writing to the Owner or Owner’s Representative.

7. The Contractor shall protect existing facilities, structures and utility lines from damage and shall protect their work, adjacent property and the public. The Contractor is solely responsible for job site safety, construction procedures and damage or injury due to their act or neglect.

8. The Contractor shall suitably document existing conditions prior to commencement of the work and shall restore all damaged or disturbed areas to meet or exceed original site conditions to the Owner’s satisfaction.

9. The Contractor shall document all deficiencies and damages, including active leaks, before and after repair using videos or photos.

10. The Contractor shall provide 48 hours minimum advance notice to the Owner or Owner’s Representative for all required field reviews.

11. The Contractor shall coordinate with the Owner all items to be contracted, supplied or installed by Owner.

12. The Contractor is responsible for all building, permit, review, license and development fees required to complete the project.

13. The Contractor shall assemble and install materials and products in strict accordance with the manufacturer’s instructions and with industry / association standards.

14. Materials or work described in words which have a well-known technical trade meaning shall be held to refer to the recognized standard. All materials shall be new, unless otherwise noted.

4.6 Shop Drawings and Other Submittals

1. Review of submittals by the Owner or Owner’s Representative is for general conformance with the design concept as presented by the repair protocol and performance specifications. No detailed check of quantities or dimensions will be made. Only those submittals required to be submitted will be reviewed. All others will be returned without review.

2. All submittals shall be accompanied by a letter of transmittal. Contractor’s submittal number shall be indicated on transmittal. Do not combine different submittals on the same transmittal. Submit shop drawings in a timely manner, consistent with the above, and prior to fabrication, installation or commencement of the work. Allow up to 10 working days for Owner or Owner’s Representative to review and return shop drawings. Number of copies of each submitted shop drawing shall be sufficient for Owner or Owner’s Representative to retain 2 copies.

3. All submittals must bear evidence of Contractor’s review (including company stamp and dated signature of reviewer) and must be approved or approved as noted by the Contractor prior to submitting to the Owner or Owner’s Representative.

4. All changes and additions made on resubmittals must be clearly flagged and noted. The purpose of the resubmittals must be clearly noted on the letter of transmittal. Owner or Owner’s Representative review will be limited to those items causing the resubmittal.

5. Do not reproduce the structural drawings for use as erection, placing or fabrication drawings.

6. Submittals not meeting the above criteria or submitted after fabrication will not be reviewed.

7. As a minimum, the following shall be submitted, as applicable, to the Owner or Owner’s Representative for review and compliance with the intent of the contract documents prior to fabrication, installation, or commencement of the work:

A. Repair mortars / hydraulic cement.

B. Bonding agents.

C. Miscellaneous metal fabrications.

D. Paint, sealant, toppings, primers, coatings and other finish products.

E. Dewatering Plan.

8. Welder certifications for all welders shall be submitted. Certifications must have been issued within 3 years prior to performing work on the project.

9. Requests for substitutions shall be submitted in writing to the Owner or Owner’s Representative for review. Submit copies of all product data and cut sheets as necessary to show compliance with the project requirements. Contractor shall bear the burden of obtaining authorization for use of items to be substituted. Owner or Owner’s Representative’s decision regarding substitutions shall be final.

4.7 Steel Notes

1. Design, fabricate and erect structural steel in conformance with the American Institute of Steel

Construction (AISC) "Steel Construction Manual" - current edition, "Code Of Standard Practice For Steel Buildings And Bridges" - current edition, and “Specification for Structural Steel Buildings" -current edition.

2. Verify all dimensions as required prior to fabrication of any structural steel.

3. Materials:

• Structural plates shall conform to ASTM A36 (fy= 36 ksi, fu=58 ksi).

4. Use structural steel that is fully weldable within grades and from any grade to any other grade.

Weld all shop connections, unless otherwise noted.

5. Use electrodes conforming to AWS D1.1, E70 series, unless otherwise noted.

6. All welding shall be done by an AWS certified welder and in compliance with AWS D1.1. All weld sizes shall be the maximum allowed by the material being welded with E70xx electrodes, unless noted on details.

7. At the Contractor’s option, substitution of shop welds for field welds may be requested. All such substitutions shall be clearly noted on the shop drawings and submitted to the Owner or Owner’s Representative for review.

8. Connections not detailed in the repair protocol shall be designed and detailed by fabricator according to AISC specifications.

9. Submit structural steel shop drawings to Owner or Owner’s Representative for review prior to fabrication. Do not reproduce the structural drawings for use as shop drawings.