Establishing the correlation of the vertical and horizontal passive failure pressure in front of constructed tbm tunnels face in sand

Anh Tuan Nguyen,Van Dung Tran

doi:10.32347/2410-2547.2020.105.33-47

Anh Tuan Nguyen, Van Dung Tran

Open Access

https://doi.org/10.32347/2410-2547.2020.105.33-47

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Abstract

The paper aims to investigate the relationship between factors which have the impacts on the tunnel and the ground and establish formulas to calculate the correlation of the passive failure pressure in front of tunnel face in the vertical and horizontal directions by using the Finite Element Method (FEM).

Highlights

The Finite Element Method (FEM) was formed from the 40s of the twentieth century and is widely used up to now to find solutions to the problem of elasticity, elasticity - plasticity, ductility - plasticity
It can be seen that the calculated results of stress in vertical and horizontal direction in front of tunnel face from Formula (10) and results from FEM are approximately the same
It is necessary to calculate the minimum amount of bentonite to avoid the instability of tunnel face. - For the small errors, it can refer to the given formula to determine the stress in front of tunnel face in the vertical and horizontal directions

Summary

Introduction

The Finite Element Method (FEM) was formed from the 40s of the twentieth century and is widely used up to now to find solutions to the problem of elasticity, elasticity - plasticity, ductility - plasticity. Its advantage is taking into account the discontinuity and heterogeneity of stratigraphic structures, which can solve complex boundary problems and calculate the values of stresses - their deformation and distribution Thanks to these distribution rules, it helps analyze the mechanism of underground construction. The convenience of numerical analysis methods has been proven Both the behavior of the materials and boundary conditions have been included in the calculations, and the study of parameters to improve the design of tunnel construction can be done more . Working principle of EPB-TBM is that the excavated soils will be mixed with water, clayey slurry or additives such as foam or polymer This mixture will form a layer pasting on the boring chamber and creates a balancing pressure versus overburden pressure of ground, and this mixture shall be removed out through conveyors upon completion of construction.

7.45 Sandy soil

Conclusion