Unbalanced foundation pit support design method

Abstract

A unbalanced foundation pit support design method comprises the steps of determining parameters of a foundation pit design model; determining a displacement mode of a support structure; determining the position of an inner brace (3); determining the parameters of a support structure at one deeper side of a foundation pit according to a traditional single fulcrum pile static balance method; determining the parameters of a support structure at one shallower side of the foundation pit according to a soil pressure computation method opposite to the traditional mode; supporting at a bounding surface between the deep foundation pit and the shallow foundation pit by adopting a traditional cantilever support structure; determining a support structure material and reinforcing bars according to a maximal bending moment and a maximal shear force of each support structure; finally performing whole stability checking calculation, antidumping checking calculation, and anti-heaving stability checking calculation. By adopting the unbalanced foundation pit support design method, the characteristic of unbalanced pressures at two sides of the unbalanced foundation pit is fully used, the pressure resistant property of a soil body is played, materials are saved and construction period is shortened under the premise of ensuring safety, and the method has very high promotion and application values.

Description

technical field [0001] The invention relates to an unbalanced foundation pit support design method, which belongs to the technical field of civil engineering construction. Background technique [0002] With the development of urbanization, the problem of land shortage has become increasingly prominent, and the development of underground space has become more and more important. The scale of underground space development is getting bigger and bigger, and the corresponding foundation pit support technology is required to be continuously improved to solve various engineering problems. [0003] At present, the foundation pit support technology for various complex environments is constantly improving, but because these deep and large foundation pits are usually located in the center of dense cities, often close to buildings, traffic arteries, subway tunnels and various underground pipelines, etc., the construction conditions are complex, Major vicious foundation pit accidents st...

AI Technical Summary

Problems solved by technology

[0003] At present, the foundation pit support technology for various complex environments is constantly improving, but because these deep and large foundation pits are usually located in the center of dense cities, often close to buildings, traffic arteries, subway tunnels and various underground pipelines, etc., the construction conditions are complex, Major vicious foundation pit accidents still occur from time to time

Moreover, the current foundation pit support technology involves the support of symmetrical foundation pits (the lateral pressures on the opposite sides of the foundation pit are the same), and the purpose of the support is mainly to prevent the soil around the foundation pit from collapsing into the pit. In engineering practice, due to the limitation of the engineering environment and the needs of construction, the existence of pits in pits such as elevator shafts and sumps makes foundation pits often unbalanced (the lateral pressures on opposite sides of the foundation pit are not the same), and may occur The support structure on the deeper side of the excavation of the foundation pit is pressed by the inner support to tilt the support structure on the shallower side of the excavation to the outside of the pit, which causes the instability of the foundation pit enclosure structure and even damages the surrounding buildings

Moreover, the design of symmetrical foundation pits is designed according to the displacement mode of the support structure into the pit, which cannot make full use of the compressive capacity of the soil, resulting in great waste

Images