Open caisson construction method based on thixotropic mud resistance reduction

Abstract

The invention discloses an open caisson construction method based on thixotropic mud resistance reduction. The open caisson construction method comprises construction preparing work, foundation pit excavating, sand cushion layer and plain concrete cushion layer manufacturing, foundation pit excavating, sand cushion layer and plain concrete cushion layer manufacturing, open caisson first joint, second joint and third joint manufacturing, open caisson first-time sinking, open caisson fourth joint and fifth joint manufacturing and open caisson second-time sinking. The water-discharge-free sinkingtechnology is adopted in the open caisson, the soil sampling manner is cooperation of air mud suction and divers, and pressing sinking method sinking and thixotropic mud resistance reduction sinkingassisting are adopted in the sinking assisting manner. Open caisson underwater plain concrete bottom sealing, open caisson bottom plate manufacturing and pipeline buttress, mud discharging well and tail work construction are conducted. The thixotropic mud sinking assisting method is adopted for lowering disturbance influences on a surrounding soil body from the open caisson to a great degree, thestatic force action on the soil body from thixotropic mud is distributed according to the triangle, and in the thixotropic mud gel state, molecules of the thixotropic mud are arranged to form a certain net-shaped structure framework, and the thixotropic mud has the functions of reducing friction force and maintaining soil wall stability in open caisson sinking.

Description

technical field [0001] The invention relates to the technical field of caisson construction, in particular to a caisson construction method based on thixotropic mud drag reduction. Background technique [0002] The sinking of the caisson mainly passes through the soil layers, which are plain fill soil layer, silt layer, silty clay layer, and silty sand layer. Among them, the silt layer and silty clay layer have low strength, low permeability, high water content, high compressibility, high sensitivity, thixotropy and rheology. Compared with the silty sand layer, the borehole friction resistance and bearing capacity of the silt layer and silty clay layer are greatly reduced. After the caisson sinks through the silty sand layer and enters the silty clay layer, it is prone to the unfavorable phenomenon of caisson inclination and sudden settlement, which is likely to bring great disturbance to the external soil, and the structure is prone to uneven settlement and deformation , ...

AI Technical Summary

Problems solved by technology

After the caisson sinks through the silty sand layer and enters the silty clay layer, it is prone to the unfavorable phenomenon of caisson inclination and sudden settlement, which is likely to bring great disturbance to the external soil, and the structure is prone to uneven settlement and deformation , cracking and other phenomena; at the same time, the anti-uplift coefficient of the caisson is small, and the soil bin in the well cell will be uplifted to a certain extent during the sinking process

The traditional caisson sinking process has disadvantages such as difficult correction of caisson posture, difficult control, slow sinking, long construction period, large friction force and poor soil wall stability during caisson sinking, and large soil disturbance outside the caisson. The differential distribution of layers causes the attitude deviation of the caisson in different subsidence stages, which is difficult to control

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