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

Abstract

The invention discloses a weak perturbation inclined rotary jet group pile occlusion strengthening method used for a shield passing underneath a house. The method includes the steps that the driven position, the pile forming angle, the driven depth and the reserved empty pile position of a rotary jet pile are determined according to the position relationship of the house and a tunnel; the hole drilling parameter is determined, and an inclined hole is drilled; the ground initial height within a preset scope is detected; and the lower portion of a drilling rod is driven into the inclined hole for rotary jet pile construction, the drilling rod at least comprises one suction multiple pipe, the ground height is detected in real time in the work progress, if the rising amount of the ground height of any position within the preset scope is larger than a first threshold value, the suction multiple pipe is used for slurry pumping until the ground height does not rise any more, and if the falling amount of the ground height of any position within the preset scope is smaller than a second threshold value, the suction multiple pipe is used for injecting water or air until the ground height is not reduced any more. By means of the weak perturbation inclined rotary jet group pile occlusion strengthening method, stratum disturbance influences can be reduced to the maximum degree, the technological process is simple, and ground subsidence caused by the shield underneath pass house can be effectively reduced.

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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