Maintenance structure for foundation pit next to existing building and construction method

Abstract

The invention relates to a maintenance structure for a foundation pit next to an existing building. The maintenance structure is characterized by mainly comprising a cement mixing pile water stop curtain, a cast-in-situ bored pile support pile, non-soil-squeezing anti-overturning piles and a slant pull rod, wherein the cast-in-situ bored pile support pile, the cement mixing pile water stop curtain and the non-soil-squeezing anti-overturning piles are sequentially arranged on the outer side of a foundation pit excavation side boundary from inside to outside; a raft plate is arranged in a pile body top area from the non-soil-squeezing anti-overturning piles to the cast-in-situ bored pile support pile, and a continuous perforated steel plate is arranged on the top of the raft plate; the upper portion of the slant pull rod is arranged on the continuous perforated steel plate on the tops of the non-soil-squeezing anti-overturning piles, the lower portion of the slant pull rod is arranged on the outer side of the cast-in-situ bored pile support pile, and the two ends of the slant pull rod are each fixed with an anchorage device, a base plate and a pedestal. The foundation pit maintenance structure effectively solves the technical problem that the foundation pit next to the existing building is hard to support, and has good technical and economical benefits.

Description

technical field [0001] The invention relates to a foundation pit maintenance structure and construction method adjacent to an existing building, which belongs to the field of foundation engineering, and is suitable for foundation treatment projects of newly-built road projects or reconstruction and expansion projects with large soft soil layers and high requirements for foundation settlement control. Background technique [0002] Along with the rapid development of the national economy, China's urbanization process is also accelerating. Land, as an essential part of urban construction, has become the main factor affecting urbanization. In order to save construction costs and improve land utilization, urban buildings are increasingly high-rise and dense. "Features. The foundation pit enclosure structure is an organic body that interacts with the soil and the enclosure structure. It must not only ensure the stability of the foundation pit and the safety and convenience of ope...

AI Technical Summary

Problems solved by technology

However, when using these enclosure structures, it is necessary to reserve a thick wall space, and at the same time, it is necessary to reserve enough operating space on the outside of the underground building, resulting in a waste of land resources. For soft soil, the deformation of the foundation pit is also serious.

[0003] The deep foundation pit enclosure structure often adopts the method of bored pile row pile support and cement mixing pile water-stop curtain. This enclosure structure can achieve good support and water-stop effects under suitable engineering conditions, but for When the foundation pit is adjacent to the existing buildings, there are often problems such as excessive deformation of the foundation pit and insufficient anti-overturning ability. If the method of adding anchor rods is used to damage the potential foundation of the adjacent existing buildings, if the inside of the foundation pit Setting too many horizontal internal supports has a serious impact on the foundation pit construction, so how to solve the problem of deep foundation pit support adjacent to existing buildings has become a research hotspot

[0004] To sum up, although the existing foundation pit enclosure structure has a good effect in strengthening the bearing capacity of the foundation soil and enhancing the water-proof and anti-seepage effect of the foundation pit, it has also achieved the expected enclosure under suitable engineering conditions. However, for the situation where the foundation pit is close to the existing buildings, there are still things that can be improved in terms of the deformation of the foundation pit and the ability to resist overturning.

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