Large diameter tunneling close range down-traversing small diameter subway tunnel distortion control method

Abstract

The invention discloses a method for controlling distortion for deep large diameter shield tunnels to under-pass small diameter tunnels, which pertains to the technical field of tunnel engineering. According to the method, the control range of the stratum loss ratio of newly established tunnels and the optimum value of the support pressure of the shield cut surface are acquired by using the finite-element method; soil pressure in front of the shield cut surface is kept relatively balanced by setting the optimal value of the support pressure, and the support pressure fluctuation range of the cut surface is controlled to range from minus 10kPa to plus 10kPa; the stratum loss ratio of the newly established tunnels is controlled within the allowed range. According to the construction technique measures, a test propelling area is arranged before the shield reaches a cross position. In the area, construction is carried out according to the situation of the existing underground tunnels above; and construction parameters are controlled and regulated to adjust the support pressure, the propulsive velocity and the amount of the grout to be injected in time; the shield passes through the cross position in combination with the optimal values of the construction parameters of the test propelling area. The invention can not only ensure the construction of tunnels to be carried out safely and smoothly, but also minimize the influence of construction on ambient environment.

Description

technical field [0001] The invention relates to a control method in the technical field of tunnel engineering, in particular to a deformation control method for a large-diameter deep-buried shield tunnel passing under a small-diameter tunnel. Background technique [0002] With the advent of the climax of urban underground space development, the use of shield method to build various urban tunnels such as underground railways has attracted more and more attention in countries all over the world. In the past ten years, the shield tunneling method has developed rapidly in my country, and has successfully mastered technologies such as earth pressure shield tunneling and mud-water shield tunneling; taking Shanghai as an example, at the end of 2007, the subway shield tunnel had reached more than 200km, and there were other crossing tunnels. 5 large-section shield tunnels at the bottom of the Huangpu River. In Shanghai's new urban planning, the total mileage of rail transit has reac...

AI Technical Summary

Problems solved by technology

This method is only suitable for open-cut construction, and is limited to new structures above existing tunnels, and is not suitable for underground excavation construction, especially for newly-built large-diameter tunnels passing through existing small-diameter tunnels

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