Foundation pit supporting system and construction method thereof

Abstract

The invention discloses a foundation pit supporting system comprising a prestressed pipe pile cement soil wall, prestressed balance anchor rods, a ground cover plate and stiffening ribs. The prestressed pipe pile cement soil wall comprises prestressed pipe piles and three-axis cement soil stirring piles, and the prestressed pipe piles are inserted into the three-axis cement soil stirring piles. The prestressed pipe pile cement soil wall and the ground cover plate are in consolidation connection. The stiffening ribs are arranged at the junction corner of the prestressed pipe pile cement soil wall and the ground cover plate. The ends of the prestressed balance anchor rods are anchored in a hard soil layer, and the other ends of the prestressed balance anchor rods are fixed on the ground cover plate in a penetrating mode. The invention further discloses a construction method of the foundation pit supporting system. The foundation pit supporting system is simple in structure, convenient to operate, safe, reliable and low in cost, especially suitable for foundation pit supporting of an urban central zone which is narrow in construction space, close to an existing building (structure) and high in practicability.

Description

technical field [0001] The invention belongs to the field of foundation pit support in geotechnical engineering, and in particular relates to a foundation pit support system and a construction method thereof, in particular to a foundation pit support system and a construction method of a narrow site. Background technique [0002] With the improvement of the level of urbanization in our country, the extensive and efficient use of underground space is an important way to solve the three major crises of urban population, resources, and environment and to implement sustainable urban development. Due to the limitations of urban construction land, the severity of the surrounding environment, and the complexity and uncertainty of the problems involved in the excavation and enclosure of foundation pit engineering, foundation pit engineering is still a very challenging, high-risk, difficult subjects. [0003] In the design of building foundation pit support, flexible support and rig...

AI Technical Summary

Problems solved by technology

There are many types of enclosure walls, including underground diaphragm walls, cast-in-place pile enclosure walls, steel-cement-soil mixing walls, steel sheet pile enclosure walls, and reinforced concrete sheet pile enclosure walls; traditional enclosure walls are generally perpendicular to the ground , the construction is more convenient, but the soil pressure is the largest, and the cast-in-place piles are non-prestressed cast-in-place piles, the quality of the piles is not easy to control, the bearing capacity of the pile body is low, and it is not easy to give full play to the strength of the pile itself;

[0004] The internal support of the enclosure wall combined with the internal support system can be supported by steel support or reinforced concrete. When the area of ​​the foundation pit is small, its technical and economical efficiency is better, but when the area of ​​the foundation pit reaches a certain scale, due to the need to install and remove a large number Therefore, the economy is poor. At the same time, the use of internal supports is likely to cause inconvenience in the construction of the main structure in the foundation pit, and damage to the support during disassembly. Generally, the construction site in the city is narrow, and the distance between the foundation pit and the existing building (structure) Therefore, the traditional large-angle inclined anchor rod cannot be installed in the foundation pit support, and it is easy to exceed the construction red line when the large-angle inclined anchor rod is installed; in addition, when the support system is removed, the enclosure wall will undergo secondary deformation, and the support will be removed. Blasting and discarded concrete fragments after demolition have negative impacts on the environment

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