Construction method of steel sheet pile cofferdam of water area no-covering-layer low pile cap

Abstract

The invention discloses a construction method of a steel sheet pile cofferdam of a water area no-covering-layer low pile cap. The method comprises the following steps that the part, at the design position of the steel sheet pile cofferdam, of a riverbed surface is cleaned; according to the design position, a guiding device is arranged at the corresponding position on a water surface, and the guiding device is welded to brackets of steel pipe piles; groove milling does not need to be conducted on the part, at the design position, of a rock stratum, the steel sheet piles are inserted and driveninto the design position in the outer wall direction of the guiding device, and the steel sheet piles are sequentially connected end to end to form the steel sheet pile cofferdam; a bottom-layer innersupport is lowered into the steel sheet pile cofferdam, and the bottom layer inner support and the steel sheet pile cofferdam are welded and fixed through pulling rods; a middle-layer inner support and a top-layer inner support are sequentially lowered into the steel sheet pile cofferdam and fixed; and high-pressure grouting is conducted on the part, in the steel sheet pile cofferdam, of the rockstratum through a grouting device, so that the part, in the steel sheet pile cofferdam, of the rock stratum is impermeable. According to the method, the characteristics of self-strength and stabilityof the rock stratum are fully utilized, so that the design length of the steel sheet piles is effectively reduced.

Description

technical field [0001] The invention relates to the field of bridge construction, in particular to a construction method of a steel sheet pile cofferdam with a low pile cap without covering layer in a water area. Background technique [0002] Under the geological conditions of conventional geology and thick covering layer, the difficulty of underwater foundation construction is relatively small, but when there is no covering layer at the foundation position of the bridge, and the cap is completely located in the rock layer, the steel pipe pile can be completed by using the drilling platform Finally, the steel sheet pile cofferdam needs to be inserted and driven into the rock formation, and then the cap is constructed. The construction of the cap under such conditions is very difficult. At present, for the construction of caps without covering layers, most of them adopt the static pressure pile planter method or the artificial covering layer method for construction. [0003]...

AI Technical Summary

Problems solved by technology

[0004] 1) The construction of the static pressure pile planter method has higher requirements on the ability of technical personnel

[0005] 2) The construction speed of the static pressure pile machine method is slow. For projects with complex geological conditions, an average of 2 to 3 steel sheet piles are implanted every day, which seriously restricts the construction period

[0006] 3) The static pressure pile machine method is used to implant steel sheet piles, the construction unit price is high, and it can only be used in rock formation geology with rock strength less than 30MPa

[0008] 1) The artificial overburden method needs to fill a large amount of medium-coarse sand at the design position of the steel sheet pile cofferdam, which cannot be accurately estimated due to the influence of water flow velocity and water depth

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