The affected area should be thoroughly cleaned to sound wood. Galvanized nails are driven into the wood within the deteriorated areas to provide a mechanical connection for the patch. The holes are filled with commercially available portland cement in the following manner: the mortar is formed into grapefruit-sized balls on the surface, lowered to the diver in a bucket, and pressed by the diver into the hole.
Ship's felt and treated boards can be used to repair localized damage. The deteriorated area is cleaned thoroughly to sound wood. The area is covered with creosoted ship's felt and fastened in place with galvanized roofing nails. The felt is then covered with 1-inch-thick creosoted boards and fastened with galvanized nails.
Planning and estimating data for repair of timber sheet pile structures are provided in Table 5-36 (using hydraulic cement patching) and in Table 5-37 (using ship's felt and creosoted boards).
5.10.2 Concrete Capping/Facing
Large-scale deterioration of timber sheet pile structures can be repaired using concrete capping/facing techniques. Concrete capping is used when extensive deterioration has occurred on the top of the timber wall but the remainder of the wall is basically sound. This method is described in detail in Section 5.6.2. All marine growth and unsound wood must be removed before a concrete cap or face is installed.
Concrete capping techniques usually require heavy equipment that is not normally available to the UCTs and would usually be carried out by others.
5.10.3 Tieback System Installation/ Replacement
Movement of timber walls can be arrested by installing a new tieback system or replacing the defective elements of an existing system. This repair/maintenance technique is explained in Section 5.6.4.
Tieback system installation/replacement is usually carried out by shore-based construction forces.
5.10.4 Wall Load Modification
Timber wall movement can also be arrested by changing the in-place loading on the wall. The technique is discussed in Section 5.6.5.
Wall load modification is usually carried out by shore-based construction forces.
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