CAJ | 학술논문

对不排水均质黏土地基隧道开挖失稳三维破坏模式进行改进，弥补了目前隧道开挖稳定性问题中三维极限分析上限法的不足。采用截椭圆柱体构造多块体平动破坏模式，克服了现有三维多块体平动破坏模式与隧道开挖面不完全接触的缺陷；进一步针对三维多块体平动破坏模式存在的问题，提出了多块体转动–剪流组合破坏模式，得到了均质黏土地层中隧道开挖稳定的上限解，明显改善了现有的极限分析上限解，并与三维弹塑性有限单元法结果及文献中的离心试验结果进行对比，验证了上限分析方法的有效性。
대불배수균질점토지기수도개알실은삼유파배모식진행개진，미보료목전수도개알은정성문제중삼유겁한분석상한법적불족。채용절타원주체구조다괴체평동파배모식，극복료현유삼유다괴체평동파배모식여수도개알면불완전접촉적결함；진일보침대삼유다괴체평동파배모식존재적문제，제출료다괴체전동–전류조합파배모식，득도료균질점토지층중수도개알은정적상한해，명현개선료현유적겁한분석상한해，병여삼유탄소성유한단원법결과급문헌중적리심시험결과진행대비，험증료상한분석방법적유효성。
The three-dimensional failure mechanism for the face stability of tunnel in pure clay under undrained condition is improved. As in the existing 3D translational multi-block collapse mechanism, the intersection of the circular truncated cylinder with the tunnel face is an ellipse surface that does not cover the entire circular face of the tunnel. The truncated elliptical cylinder is adapted to construct the 3D translational multi-block failure mechanism. In the present 3D mechanism, all the radial cross-sections of the rigid block are elliptical, and the intersection of the cylinder with the tunnel face is a circular face. The 3D collapse mechanism is further modified to intermix rotating multi-block and homogeneous shear zone, and the corresponding upper bound solution significantly improves the existing limit analysis. The validity of the combined upper bound solution for the tunnel stability in clays is demonstrated by comparing with the existing 3D finite element and centrifuge results.