Post-arranged inner supporting structure for partitioned excavation of super-large deep foundation pit and construction method

Abstract

The invention relates to a post-arranged inner supporting structure for partitioned excavation of a super-large deep foundation pit and a construction method. The method is characterized in that an outer support pile, an inner support pile and a pile top solidified soil layer are arranged on the outer side wall of the foundation pit firstly, and lower top beam positioning bar bodies and upper top beam positioning bar bodies are implanted in the inner support pile; then step-slope excavation is conducted on soil in the middle of the foundation pit from the middle to the two sides of the foundation pit, and a pit bottom drainage layer, a geogrid layer, a post-cast strip ground beam, anti-floating anchors and a solidified cement soil layer are arranged in the positions, at the bottom of the foundation pit, of the excavated area; and a post-arranged inner support is arranged between an adjustable bracket on the post-cast strip ground beam, and a pile top beam, then soil below the post-arranged inner support is excavated, pit bottom reinforcing piles, a pit bottom drainage layer, pit bottom drainage ditches and a solidified cement soil layer are arranged at the pit bottom below the post-arranged inner support, and finally, the post-arranged inner support is removed. The force-bearing behavior of a foundation pit supporting system can be improved, in addition, the excavation rate of the foundation pit can be increased, and the amount of materials for foundation pit supporting can be decreased.

Description

technical field [0001] The invention belongs to the field of underground engineering, and in particular relates to an internal support structure and a construction method after divisional excavation of a super-large deep foundation pit. Background technique [0002] With the development of construction technology and the continuous development of urban underground space, there are more and more deep foundation pit projects; in the construction of many deep foundation pit projects, it often encounters the situation of large plane size, complex geological conditions, and strict deformation control. Engineering practice shows that when excavating super-large deep foundation pits, not only the safety level of foundation pit support, geological conditions, depth of foundation pit, surrounding environment, plane size and shape of foundation pit, construction site conditions, etc. From the economic point of view, the form of foundation pit support and construction technology are an...

AI Technical Summary

Problems solved by technology

Although the structure has made some innovations in the improvement of the mechanical performance of the hollow pipe pile and the overall reinforcement of the support structure, it has not solved the engineering problems such as the improvement of the mechanical properties of the support structure, the performance of soil support performance, and the improvement of construction efficiency.

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