Protection control method for resisting longitudinal deformation through shield tunnel structure in soft soil stratum

Abstract

The invention discloses a protection control method for resisting the longitudinal deformation through a shield tunnel structure in a soft soil stratum, which comprises the following steps: getting division information of soil layers of shallow soil containing a tunnel, and then extracting soil samples of the soil layer in which the tunnel is located for performing an indoor conventional geotechnical test; utilizing a water level gauge to measure the bulk settling of the tunnel structure, taking the longitudinal direction of the tunnel as a horizontal axis, and taking the accumulated settlingvalues of the tunnel as a longitudinal axis for marking up the accumulated settling values of all rings of the tunnel; performing sectional fitting on an accumulated settling curve of the tunnel and determining a Gaussian fitting equation of the accumulated settling curve; determining the shear force of the tunnel; and determining the shearing stress and the pulling stress of each bolt and controlling the longitudinal deformation of the tunnel according to the obtained shearing stress and the pulling stress of the bolts between the rings of the tunnel. The protection control method adopts a Cosserat non-equilibrium mechanical theoretical system to quantitatively determine the stress of the bolts between the lining rings of the tunnel, and the method is simple, convenient to popularize andsuitable for the control problem of the longitudinal deformation of the shield tunnel.

Description

technical field [0001] The invention relates to a method in the technical field of construction engineering, in particular to a method for protecting and controlling a shield tunnel structure against longitudinal deformation in soft ground. Background technique [0002] With the acceleration of the urbanization process in our country, the urban population is increasing and the available space is getting less and less. The development of urban underground rail transit not only relieves the heavy traffic pressure in the city, but also effectively utilizes the urban space and contributes to the sustainable development of the city. made an important contribution. The shield tunneling method is a commonly used underground tunnel construction method. It has the characteristics of safe construction, fast excavation speed, and automatic operation. It is the best choice for long-distance tunnel excavation in weak water-bearing strata. However, shield tunnels in soft ground are prone...

AI Technical Summary

Problems solved by technology

It is not difficult to find that the current structural design of shield tunnels simplifies the tunnel into a two-dimensional model, only considering the force deformation on the cross section of the tunnel, but there is no targeted analysis of the longitudinal deformation and structural force caused by the long-term operation of the tunnel , for tunnel longitudinal bolts, it is completely empirically designed

my country's "Code for Design of Subway Railways (GB50157-92)" recommends the use of the transverse design method of the load structure model, and does not consider the influence of the longitudinal deformation of the tunnel

Compared with the 1999 edition (DGJ08-11-1999), the 2010 edition of "Shanghai Foundation Design Code" (DGJ08-11-2010) puts more emphasis on the influence of the longitudinal settlement of the tunnel, and puts forward the maximum opening of joints and the limit of staggered platforms between rings. However, there is still a lack of clear instructions on the analysis method for the longitudinal design of the tunnel, and there is no quantitative determination method for the bolt force analysis

This "staggered platform" deformation mode is essentially different from the tunnel bending mode modeled on a homogeneous ring, so the longitudinal equivalent continuous model cannot accurately calculate the internal force of the bolt.

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