Figure 1 Repairs to steel sheet pile walls using various patching techniques

Table 5-14

Planning and Estimating Data for Steel Sheet Pile Repair Using Epoxy Patch

Description of Task: Repair a deteriorated steel sheet pile wall by patching with fabric mesh covered with hand-applied epoxy mastic. A 1-ft2 area below the low waterline is to be patched.

Size of Crew: Dive station, one laborer

Special Training Requirements: Familiarity with procedures for removal of marine growth and placement of epoxy mastic underwater.

Equipment Requirements: High-pressure waterblaster, hydraulic grinder with Barnacle Buster attachment, high-pressure pump for waterblaster, hydraulic power unit, protective clothing for personnel handling epoxy materials, float stage or work platform.

Productivity of Crew: 1 hour for a 1-ft2 patch. Materials:

Fabric Mesh - The fabric mesh must cover the entire hole to be patched as well as extending over the surrounding sound metal. The area of the holes to be patched should be estimated and a 25 percent allowance made for extra material.

Epoxy Patching Compound - Epoxy patching compounds are usually purchased in two-component kits with an aggregate additive. A 1-gallon kit might include 1 gallon of each component plus aggregate, resulting in more than a 2-gallon yield. Patching coverage is measured in square feet per gallon. The required patching yield is obtained by taking the square footage to be covered and dividing by the square foot per gallon coverage rate. The square footage should be based on the size of the fabric mesh, which is considerably larger than the size of the hole being covered.

Potential Problems: If water temperature is less than 60°F, proper adhesion to the sheet pile may not occur. Successful patching requires a neutral or positive charge on the structure; negatively charged steel repels the negatively charged epoxy patching compound. Underwater application may be difficult. Skin irritation may occur if individual is sensitive to the epoxy material.

Table 5-15

Installing a Concrete Cap and Partial Face on Sheet Pile Wall

Problem: Major damage to steel sheet pile precluding the use of patches for repair.

Caution: Block off pier deck from traffic. Notify port authority to secure marine traffic and obtain clearances to begin construction.

Description of Repairs: (Figure 1). Concrete cap and partial face is installed over damaged area. Engineering required to: validate soundness of existing sheet pile to carry additional load of new cap; determine die need and design for additional tiebacks; provide recommendations for concrete dimensions, reinforcing steel dimensions, and placement; and evaluate the need for corrosion protection.

• Remove existing surface treatment (decking) to provide access to front and back of seawall.

• Clean sheet pile to be capped with high-pressure waterblasting. Use sandblasting above waterline.

• Excavate behind the wall to allow installation of cap and backface if required. Concrete behind sheet wall may not be required.

• Excavate trenches and install new tieback system with wale as required. Electrically isolate tieback assembly from sheet pile using insulation washers and collars.

• Install reinforcing both front and back and attach by welding to existing sheet pile.

• Fabricate and install forms to provide a minimum 6-inch thickness of concrete both front and back.

• Pour front and backface at low water level.

• Install forms for concrete cap and pour when ready.

• Remove forms after concrete has cured, backfill behind seawall, and replace decking.

• Install fender system as required.

Application: Restores structural strength at top of wall and prevents loss of soil through holes in sheet wall. Requires installing a cathodic protection system to prevent accelerated corrosion at the underwater interface between concrete cup and sheet pile.

Inspection Requirements: Annually inspect sheet pile aiea immediately under concrete cap.

New concrete cap Construction joint—s^

Wire mesh reinforcing

To protect new tie rod, install plastic isolator collar/washer

Excavate for new cap and backfill after

Existing tie ro

Wire mesh reinforcing

Excavate for new cap and backfill after

To protect new tie rod, install plastic isolator collar/washer

Existing tie ro

To prevent accelerated — corrosion here, install a cathodic protection system or terminate above MHW or below mudline

Sheet Pile Cap
Attach rebar by welding to sheet pile

To prevent accelerated — corrosion here, install a cathodic protection system or terminate above MHW or below mudline

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Responses

  • samlad took-brandybuck
    How fix mesh on sheet pile?
    5 years ago
  • ursula
    What is patch pile wall?
    5 years ago
  • Teodros
    How to repair a concrete sea wall cap?
    5 years ago
  • Medhanit Senay
    How welding rebar to sheet piles prevent corrosion?
    4 years ago
  • ANNA-LIISA
    How piles constructed underwater?
    2 years ago

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