Method for selecting thickness of bottom sealing concrete of steel cofferdam with reinforced shearing force

Abstract

The invention discloses a method for selecting the thickness of bottom sealing concrete of a steel cofferdam with reinforced shearing force, which comprises the following steps of: firstly, calculating the thickness Lhigh of the bottom sealing concrete under the highest water level, and then calculating the thickness Llow of the bottom sealing concrete under the lowest water level; and finally, selecting the maximum value of the bottom sealing concrete thickness Lhigh at the highest water level and the bottom sealing concrete thickness Llow at the lowest water level as the final thickness of the bottom sealing concrete. The method has the remarkable effects that the minimum thickness of the bottom sealing concrete needing to be hit can be quickly and accurately obtained by calculating andcomparing the thicknesses of the bottom sealing concrete at the highest water level and the lowest water level, and a basis is provided for actual decision selection of the thickness of the bottom sealing concrete in the actual engineering construction process.

Description

technical field [0001] The invention relates to a construction guarantee method for a steel cofferdam, in particular to a method for selecting the thickness of concrete for the bottom sealing of a steel cofferdam. Background technique [0002] As the bottom plate of the steel hanging box cofferdam, the bottom cover concrete is often subjected to the most unfavorable load conditions when the water body inside the cofferdam is drained. At this time, the self-weight of the steel box cofferdam is transferred to the back concrete through the interface bonding between the cofferdam wall and the back concrete; The interfacial bonding is transferred to the steel casing. The back-sealing concrete relies on interface bonding to transmit force to the cofferdam wall and steel casing, so the interface bonding performance is crucial to the anti-sinking and anti-floating performance of the steel hanging box cofferdam. Although my country's current national standards have given the approx...

AI Technical Summary

Problems solved by technology

However, in the case where the maximum fluctuation of the water level in the Three Gorges Reservoir area can reach 30m, simply increasing the thickness of the back cover concrete not only violates the current general concept of environmental protection, energy saving and green construction, but also the height of the steel hanging box cofferdam will be increased if the back cover concrete is too thick. The structural force is more unfavorable and greatly increases the difficulty of construction

More importantly, the frequent changes of the construction water level make the back cover concrete bear the cyclic effect of anti-floating and anti-sinking alternating loads, and the interface bonding between the concrete and the steel hanging box cofferdam and the steel casing is prone to local cracking and slippage And gradually advance, resulting in leakage, concrete stress exceeding the limit and even the overall instability of the cofferdam

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