Value analysis method of underpinning pile foundation influenced by up-down overlapping tunnel shield tunneling

Abstract

The invention discloses a value analysis method of underpinning pile foundation influenced by up-down overlapping tunnel shield tunneling; the method comprises the following steps: using FLAC 3D finite difference software to simulate an underpinning pile foundation model bearing load, and parsing settlement and deformation rules; aiming at an overlapping tunnel excavation process after pile foundation underpinning, and simulating overlapping tunnel excavation by shield tunneling method; parsing ground surface settlement and pile foundation displacement stress influenced by the shield tunneling method; carrying out single factor analysis contrast for physical parameters including excavation sequence, tunnel spacing, and underpinning pile foundation deep burying, pile diameter and spacing; analyzing different factor influences on the underpinning pile foundation, thus finally obtaining the corresponding simulation value and pile foundation settlement and deformation trends. The value analysis method is creative, high in accuracy, and thus providing wide engineering application prospects.

Description

technical field [0001] The invention relates to the technical field of pile foundation underpinning in shield tunnel construction with upper and lower overlapped tunnels, in particular to a numerical analysis method for the influence of shield tunnel construction with upper and lower overlapped tunnels on underpinning pile foundations. Background technique [0002] There are many methods for excavating subway tunnels, one of which is the shield tunneling method. Tunnel shield excavation refers to the excavation of rock and soil on the design tunnel excavation line by using the excavation surface cutter head of a large shield machine under the protection of the steel shell, and at the same time, the lining structure support is formed behind the shield machine. It is an excavation method that digs a tunnel and continuously advances safely through the jacking device. [0003] In construction engineering, if the bearing capacity of the pile foundation of the building cannot mee...

AI Technical Summary

Problems solved by technology

At present, the research on the impact of tunnels is mainly on the impact of surface settlement, and there are few studies on the existence of buildings and the impact of pile foundations. In actual engineering, the impact of shield excavation on nearby pile foundations is not large. Actual measurement, while the model experiment method usually simulates a mechanical model of plane strain. The current numerical analysis method generally uses a distributed method for simulation, which cannot simulate the interaction of piles and soil more realistically.

At home and abroad, there have been many engineering cases of tunnel excavation under the condition of pile foundation underpinning the original pile foundation. Simulate construction based on human experience and engineering analogy

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