Construction method of deep foundation pit close to building and adopting underground structure as internal support

Abstract

The invention relates to a construction method of a deep foundation pit close to a building and adopting an underground structure as an internal support. The construction method comprises the following specific steps of: (1) constructing a drilling and filling pile; (2) excavating a negative-layer earthwork; (3) constructing a main body structure outside the a back-pressure earth area; (4) constructing a waist beam and installing horizontal steel supports; (5) excavating back-pressure earth and constructing a main body structure in a the back-pressure earth area; (6) removing the horizontal steel support at the -4.000m position; (7) constructing a negative-layer basement structure; (8) backfilling the back-pressure earth between a negative layer and a rotary-excavating drilling pile; and (9) removing the horizontal steel support at the -0.400m position. The construction method has the beneficial effects that the construction cost and the construction period can be reduced to a great extent; the construction difficulty is reduced and the potential hazard for water seepage of a basement is reduced; and the disturbance influence of an anchor rod on the surrounding building base is eliminated.

Description

technical field [0001] The invention belongs to the technical field of building construction, and in particular relates to a construction method for excavating underground structures adjacent to existing buildings. Background technique [0002] Since the reform and opening up, the rapid development of my country's political, economic, and cultural undertakings has brought about a climax of urban construction. Urban land resources are increasingly scarce, and urban construction gradually extends to the sky and underground. In urban construction where every inch of land is expensive, the development and utilization of underground space has become a major development trend. For this reason, excavation of underground structures next to existing buildings is becoming more and more frequent. How to ensure the safety and stability of the existing buildings adjacent to the construction process has become an important and difficult point in the construction process. The supported e...

AI Technical Summary

Problems solved by technology

However, there are new problems that follow: the criss-cross support rods in the foundation pit have a great impact on the construction space, the work of excavation machinery and transport vehicles is greatly affected, and the construction organization becomes complicated. When the arrangement and transportation of construction machinery, materials and equipment become difficult, how to replace the support, how to combine the foundation pit support structure with the main project, how the enclosure structure adapts to the pouring method of the underground main structure construction, and how to deal with the support The coordination of molding, waterproofing and other processes has become a new problem, and the total construction period is bound to be extended;

[0007] The length of the anchor rod in the soil layer is generally not less than 9m. After the construction is completed, it will be discarded in the soil layer and cannot be recycled, resulting in increased construction costs and extended construction periods.

Especially when the foundation pit is close to the existing building, the design position of the anchor in the soil layer often intersects with the foundation of the building, and the arrangement of the anchor is more difficult

Images