Construction method of open caisson

Abstract

The invention discloses a construction method of an open caisson. The construction method comprises the steps of construction preparation work; foundation pit excavation as well as sand cushion layerand plain concrete cushion layer manufacturing; open caisson first-section, open caisson second-section and open caisson third-section manufacturing; open caisson first-time sinking; open caisson fourth-section and open caisson fifth-section manufacturing; open caisson second-time sinking; open caisson underwater plain concrete bottom sealing; open caisson bottom plate manufacturing; and pipelinebuttress, mud discharging well and tail work construction. The open caisson sinks by adopting an undrained process, the soil sampling mode is matched with an air mud suction diver, and the sinking assisting mode is sinking by a pressure sinking method and resistance reduction and sinking assisting by thixotropic mud. According to the method, the sinking method is adopted, the posture of the open caisson is convenient to control, the sinking precision of the open caisson is high, the depth of open caisson blade feet penetrating into a soil layer is larger through a counter-force system, the sufficient sinking coefficient is achieved, the sinking speed of the open caisson can be greatly increased, disturbance to external soil is small, the phenomenon that a structure is prone to differentialsettlement, deformation, cracking and the like are effectively prevented, and a soil bin in a well lattice cannot be raised in the sinking process.

Description

technical field [0001] The invention relates to the technical field of caisson construction, in particular to a construction method for caissons. 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 , cracking and other phenomena; at th...

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

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