Micro-stress shelter pile foundation strengthening method

Abstract

The invention discloses a micro-stress shelter pile foundation strengthening method, relating to the bridge pile foundation strengthening technology adopted in underground construction under the pile foundation of an urban bridge. The method comprises the step that micro-stress shelter piles are arranged around the bridge foundation or the pile cap for separating the stratum under the bridge foundation and within the surrounding range of the micro-stress shelter piles from the stratum beyond the surrounding range thereof. During the construction and installation of the micro-stress shelter piles, layered high-pressure grouting is implemented, and the piles are connected into a whole through the high-pressure grouting and due to the spreading the grout, thus forming a separation wall, reducing the stress redistribution effect transmission caused by underground space excavation, avoiding the great reduction of side frictional resistance of the piles, reducing the decrease of pile bearing capacity, simultaneously being capable of preventing the shifting of surrounding soil displacement towards the original pile body, effectively controlling the transverse deformation of bridge foundation and inhibiting the settlement of the original bridge piles caused by underground space excavation, and realizing convenient, fast and high-efficiency construction in restricted space.

Description

technical field [0001] The invention relates to a bridge foundation reinforcement technology adopted for underground space construction under existing urban bridge pile foundations, in particular to miniature piles capable of stress isolation. Background technique [0002] In civil engineering construction, when the underground engineering construction affects the stability of the existing bridge foundation and needs to be reinforced, the traditional method is to expand the cap and add deep piles (Chen Yongshuan. No. 59, Beifeng Road, Guomao Station, Beijing Metro Line 10 Bridge Foundation Reinforcement Construction Technology. Prospecting Engineering (Geotechnical Drilling and Excavation Engineering), 2007 (6): 24-26.), Conventional Isolation Pile (Jia Xitao. Construction Analysis of Isolation Pile Method for Excavated Tunnel Passing Existing Buildings. Tunnel Construction 26(1): 25-26.), tree root pile (China Academy of Building Research. Technical Specifications for Found...

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Problems solved by technology

[0004](1) The clearance of urban bridges is generally low, there is no construction space, and large-scale pile-forming equipment cannot be erected. Traditional retaining pile construction techniques such as bored pile construction machinery placement and steel cage splicing are greatly restricted;

[0005](2) Driving piles around or on the original pile foundation will cause the soil structure to be disturbed, which will lead to a decrease in the frictional resistance of the original bridge piles, especially in the soil layer The disturbance is more obvious when there are gravel and silt layers with poor stability;

[0006](3) The construction period of the traditional scheme is long and the construction cost is too high

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