Combined supporting system for foundation pit central island basin type excavation and construction method thereof

Abstract

The invention provides a combined supporting system for a foundation pit central island basin type excavation and a construction method thereof. A grid type double-shaft cement-soil mixing pile gravity type enclosure wall is added to replace a soil body to slope, steel inclined struts are arranged after overall pouring of a tower bottom plate is completed, and follow-up construction work is carried out. The double-shaft cement-soil mixing pile gravity type enclosure wall is used for replacing the soil body slope, so that the length of the steel inclined struts can be properly shortened, and the influence of the steel inclined struts on foundation pit deformation is reduced; a foundation bottom plate of a tower extends to the position, close to the edge side of a foundation pit, of part ofa foundation bottom plate of a basement to be constructed, the problem of tower bottom plate cutting caused by central island basin type earth excavation is solved, the foundation bottom plate of thetower can be integrally poured, integrity and continuity of the tower structure are guaranteed, and other quality problems such as water leakage caused by improper later construction joint treatment are avoided.

Description

Technical field [0001] The invention relates to a combined support system used for basin-type excavation of the center island of a foundation pit and a construction method thereof. Background technique [0002] With the acceleration of urbanization, the development and utilization of underground space continue to increase, resulting in a large number of large-scale and irregular-sized foundation pit projects, and the formation of a variety of targeted foundation pit enclosures and Excavation technology. At present, for foundation pit projects in soft soil areas that are close to existing buildings, roads and underground pipelines, with a large plane area and average excavation depth, in addition to the conventional form of adding a large horizontal support system, the "central island" is obliquely supported Foundation pit support methods have also been applied and promoted in this kind of foundation pit engineering. [0003] The basic principle of the general "central island" obl...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a combined support system and its construction method for excavation of the island basin in the center of the foundation pit, which can solve the problems caused by the elastic compression and temperature stress of the diagonal brace itself due to the long length of the vertical diagonal brace. The problem that has a great impact on the deformation of the foundation pit; and the current large-area foundation pit engineering has many high-rise buildings, and the surrounding soil grading area often cuts into the high-rise floor, destroying the integrity and continuity of the tower structure. If the construction joints are not handled properly in the later stage, the structure will have problems such as water leakage along the joints

Images