Weak perturbation inclined rotary jet group pile occlusion strengthening method used for shield passing underneath house

Abstract

The invention discloses a micro-disturbance inclined rotary grouting group pile occlusal reinforcement method for a shield tunneling under a house, which includes: determining the setting position of the rotary grouting pile, pile forming angle, driving depth, Reserve empty pile positions; determine drilling parameters, and drill inclined holes; detect the initial height of the ground within the preset range; place the bottom of the drill pipe into the inclined hole for jet grouting pile construction, and the drill pipe includes at least one section of suction multiple The ground height is detected in real time during the construction process. If the ground height rise at any position within the preset range is higher than the first threshold, the multiple suction pipes are used to pump the slurry until the ground height no longer rises. If If the lowering amount of the ground height at any position within the preset range is lower than the second threshold value, then the multiple suction pipes are used to inject water or air until the ground height is no longer lowered. The invention can minimize the impact on stratum disturbance, has simple technological process, and can effectively reduce the ground subsidence caused by the shield tunnel passing through the house.

Description

technical field [0001] The invention relates to the field of shield tunnel construction. More specifically, the present invention relates to a ground auxiliary reinforcement construction technique in which an earth pressure balance shield penetrates a house with a shallow foundation in a full-section sand layer. Background technique [0002] The earth pressure balance shield method has become the most widely used subway shield construction method in complex strata due to its economy and wide applicability. When excavating tunnels, it is often necessary to pass through the existing dense ground buildings and structures. The excavation of the shield machine in the complex stratum often causes stratum disturbance, especially in the full-section water-rich sand layer. There are often risks of gushing and overbreak. Ground subsidence accidents are not uncommon due to excessive ground loss at the excavation face. In view of the risk of ground subsidence during shield excavation ...

AI Technical Summary

Problems solved by technology

In view of the risk of ground subsidence during shield excavation in water-rich sand layers, the existing existing methods such as ground sleeve valve pipe grouting, WSS double-liquid grout reinforcement, MJS vertical or horizontal rotary grouting piles occluded pile group anti-seepage curtain, and supplementary grouting reinforcement in tunnels, etc. The technology has been widely used. However, for the construction of shield machines in short-distance rapid side penetration and downward penetration of continuous building groups, when the ground construction site is relatively narrow and the foundation of existing structures is shallow, the bearing capacity of the foundation is small, and the ground is more sensitive to disturbance. All of the above methods have defects and relatively high risks. Often the stratum is disturbed during the reinforcement construction, causing uneven settlement of the house foundation, resulting in cracking of the house, or poor economical and applicability of the project, and sometimes a shield machine is required for a long construction period. long downtime

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