Double-wall steel cofferdam construction method

Abstract

The invention belongs to the technical field of cofferdams for water conservancy projects, and provides a double-wall steel cofferdam construction method which comprises the following steps: step 1, after pile foundation construction is completed, a drilling platform is dismantled; secondly, an assembling platform is installed on the steel casing; thirdly, the double-wall steel cofferdam is assembled and lowered, specifically, firstly, the first section of the double-wall steel cofferdam is assembled on an assembling platform, then a hoisting and lowering system is installed on the top of a steel casing, and a guiding system is installed on the periphery of the steel casing; the first-section double-wall steel cofferdam is hoisted through a hoisting system, the part, hindering lowering, in the assembling platform is dismantled, and then the first-section double-wall steel cofferdam is lowered through the hoisting system; then, the subsequent sections of double-wall steel cofferdams are spliced and lowered; fourthly, after the double-wall steel cofferdam is lowered in place, bottom sealing construction is conducted; and fifthly, multiple layers of inner supports are installed in the double-wall steel cofferdam. The construction method of the double-wall steel cofferdam has the advantages of being simple, convenient to operate, good in splicing quality and high in lowering precision.

Description

technical field [0001] The invention belongs to the technical field of cofferdams for water conservancy projects, and in particular relates to a construction method of a double-wall steel cofferdam. Background technique [0002] The 4# main pier of the main bridge of Linhuaiguan Huaihe Bridge is located in the waters on the north side of Huaihe River in Linbei Hui Township, Wuhe County. Sandy mudstone and gneiss. The thickness of the overburden (including full and strong wind sandy mudstone) is about 26.05m on average; the average thickness of the fully weathered gneiss belt is about 6.07m, the average thickness of the fragmented strong weathered gneiss belt is about 23.74m, and the average thickness of the moderately weathered gneiss belt is about 23.74m. The average thickness of the belt is about 16.94m. The soil layer and strongly weathered bedrock are broken, and the bearing capacity is low, so it is not suitable for the foundation bearing layer. The core of the modera...

AI Technical Summary

Problems solved by technology

[0005] 2. Difficulty in excavating the bottom layer: During the lowering of the double-walled steel cofferdam of the 4# main pier, it is necessary to penetrate through muddy soil, silty clay, silty fine sand, and pebble layers, and finally enter fully weathered sandy mudstone, and the pebble layer is relatively thick. Finally, about 3m into the pebble layer and sandy mudstone, there is a risk of collapse;

[0006] 3. Construction during flood season: cofferdam construction needs to cross the flood season

However, the existing cofferdam lowering construction method has the problems of complicated operation and low efficiency, and is not suitable for the surrounding rock construction of the 4# main pier of the main bridge of the Huaihe River Super Bridge in Linhuaiguan.

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