Lining pressure for circular tunnels in two layered clay with anisotropic undrained shear strength

IF 1.7 Q3 ENGINEERING, GEOLOGICAL

Geomechanics and Geoengineering-An International Journal Pub Date : 2021-12-24 DOI:10.1080/17486025.2021.2012077

B. Kumar, J. Sahoo

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引用次数: 2

Abstract

ABSTRACT In this paper, the required limiting pressure to be offered by the lining of circular tunnels formed in clay overlain by another clay layer under undrained condition has been computed. Both the layers are anisotropic in nature from the shear strength point of view. The upper layer is considered relatively either weaker or stronger than the lower layer i.e. undrained anisotropic shear strength of upper layer is relatively either smaller or greater than that of lower layer. Lower bound limit analysis coupled with finite element formulation and second order cone programming has been employed to perform the analysis. For different thickness of upper layer above crown of tunnel, the limiting lining pressure to maintain stability of tunnel has been obtained by varying thickness of lower clay layer, anisotropic parameters, normalised overburden pressure, undrained cohesion and unit weight of upper layer relative to lower layer. The solutions obtained from this analysis reveal that anisotropy in shear strength has significant effect on the required lining pressure to keep tunnel in stable condition.

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各向异性不排水两层粘土中圆形隧道衬砌压力

摘要本文计算了不排水条件下由粘土层复盖的圆形隧道衬砌所需要的极限压力。从抗剪强度的角度来看，两层都是各向异性的。上层相对于下层弱或强，即上层不排水各向异性抗剪强度相对于下层小或大。采用下限分析结合有限元公式和二阶锥规划进行分析。对于隧道顶冠以上不同厚度的上层衬砌，通过改变下层粘土层厚度、各向异性参数、归一化覆盖层压力、不排水黏聚力和上层相对于下层的单位重量，得到维持隧道稳定的极限衬砌压力。分析结果表明，抗剪强度的各向异性对保持隧道稳定所需的衬砌压力有显著影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Geomechanics and Geoengineering-An International Journal ENGINEERING, GEOLOGICAL-

CiteScore

3.80

自引率

0.00%

发文量

期刊介绍： Geomechanics is concerned with the application of the principle of mechanics to earth-materials (namely geo-material). Geoengineering covers a wide range of engineering disciplines related to geo-materials, such as foundation engineering, slope engineering, tunnelling, rock engineering, engineering geology and geo-environmental engineering. Geomechanics and Geoengineering is a major publication channel for research in the areas of soil and rock mechanics, geotechnical and geological engineering, engineering geology, geo-environmental engineering and all geo-material related engineering and science disciplines. The Journal provides an international forum for the exchange of innovative ideas, especially between researchers in Asia and the rest of the world.