Protection method for controlling deformation of building structure close to foundation pit

Abstract

The invention relates to a protection method for controlling deformation of a building structure close to a foundation pit. The protection method comprises the following steps that (1) a soil pressure meter is buried in the side, close to the building structure, of a foundation, a foundation pit deformation inclinometer tube is buried in the side close to the foundation pit, and settlement observation points are distributed on the building structure; (2) holes are vertically drilled between the foundation pit and the building structure, air bags capable of being inflated / grouted are guided into the drilling holes through guide pipes, and the orifice sections are sealed; (3) when the foundation pit is excavated, pressurizing equipment is started according to the situations of soil pressure, surrounding ground displacement and settlement changes of the building structure, and the air bags are inflated by opening an air guide pipe so as to conduct pressure compensation on unloading caused by excavation; and (4) after excavation of the foundation pit is completed, the air bags are deflated one by one, grouting is conducted at the same time, and a pile body with certain rigidity is formed. The protection method has the advantages of being high in construction speed, high in adaptability, high in efficiency, small in disturbance, low in cost and the like, and is a very effective settlement control protection method.

Description

technical field [0001] The invention belongs to the technical field of foundation pit construction, and in particular relates to a protection method for controlling the deformation of structures adjacent to the foundation pit. Background technique [0002] In recent years, China's urban construction has developed extremely rapidly, with more and more underground projects, and a large number of foundation pit projects have emerged. These deep and large foundation pits located in the center of the city are surrounded by various underground pipelines, and are close to various buildings and subway tunnels. Due to the narrow construction site of the deep foundation pit in the center of the city, the tight construction period, the deep excavation of the foundation pit (the depth is generally 15-25m), the excavation area of ​​the foundation pit is large, and the construction conditions are complicated; in addition, the stratum where the project is located is basically saturated. W...

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Problems solved by technology

[0003] At present, the method of using the conventional isolation pile technology to protect the structures adjacent to the excavation of the foundation pit has been applied to a certain extent. In addition, when the pile foundation is used for the construction near the excavation of the foundation pit, there is also a protection method of grouting on the outside of the isolation pile (that is, the side away from the foundation pit), but this method is not suitable for shallow foundations. Because the main purpose of grouting outside the pile is to increase the side friction resistance of the pile foundation of the protected building near the excavated foundation pit, and improve the deformation resistance of the pile foundation, while direct grouting under shallow infrastructure will lead to unevenness of the building lift up, cause uplift damage

[0004] In addition, in recent years, the double-row pile technology has been developed to a certain extent, and it has certain advantages in the slope support of the foundation pit adjacent to the existing building. However, the support cost of the double-row pile is relatively high, and the depth of the foundation pit support is also limited. The safety factor of the protection is low, and the construction of the rear row of piles is greatly affected by the environment behind the slope

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