Upper Bound Limit Analysis of Limit Support Pressure for Shield Excavation Face in Composite Ground

被引：0

作者：

Dai Z. ^{[1
]}

Hu Z. ^{[1
]}

机构：

[1] Inst. of Geotechnical Eng., Xi'an Univ. of Technol., Xi'an

来源：

Gongcheng Kexue Yu Jishu/Advanced Engineering Sciences | 2021年 / 53卷 / 02期

关键词：

Composite strata; Shield tunnel; Stability of excavation face; Upper bound limit analysis method;

D O I：

10.15961/j.jsuese.202000008

中图分类号：

U41 [道路工程]; TU997 [];

学科分类号：

0814 ;

摘要：

With the further development and utilization of underground space, the geological conditions faced by shield tunneling are more complex and diverse. When the shield tunnels in the composite strata, due to the differences in mechanical properties between the strata, it is easy to cause instability and damage due to improper determination of the supporting force of the excavation surface, which will bring negative impacts to the projects. It is difficult to determine the support pressure of the excavation face due to the stiffness differences between the upper and lower strata, when the shield tunnel passes through the composite strata. Based on the combined logarithmic helix failure model utilized as the instability model of the shield excavation face in the composite strata, the upper limit expression of the limit support force of shield excavation face in the composite strata was derived by using the upper bound theorem of limit analysis. The optimal solution of the ultimate support force was obtained by linear optimization technology, and the rationality of the combined logarithmic spiral failure mode was verified by comparing with the existing literatures. At the same time, the influence of different parameters on the ultimate support force and the critical failure mode were discussed, and the schematic diagram of the critical sliding surface was presented. The results showed that when the internal friction angle and cohesion of the upper stratum were fixed, the ultimate support force decreased with the increase of the internal friction angle and cohesion of the lower stratum. With the increase of the diameter of the tunnel, the ultimate support force increased significantly. The depth coefficient was defined as the ratio of the depth of the upper stratum to the diameter of the tunnel. The smaller the depth coefficient was, the more sensitive the ultimate support force was to the variations of the shear strength parameters of the stratum. But for a single stratum, the change of depth coefficient has no effect on the ultimate support force. The conclusions had a certain guiding significance for the practical engineering. Copyright ©2021 Advanced Engineering Sciences. All rights reserved.

引用

页码：95 / 102

页数：7

共 21 条

[1] Wei Liangwen, Zhang Qinghe, Sun Tongli, Et al., Current research state of face stability in shield tunnelling and future development, Journal of Chongqing Jiaotong University(Nature Sciences), 26, 6, pp. 67-72, (2007)
[2] Tang Yiqun, Song Yonghui, Zhou Nianqing, Et al., Experimental research on troubles of EPB shield construction in sandy soil, Chinese Journal of Rock Mechnics and Engineering, 24, 1, pp. 52-56, (2005)
[3] Senent S, Jimenez R., A tunnel face failure mechanism for layered ground, considering the possibility of partial collapse, Tunnelling and Underground Space Technology, 47, pp. 182-192, (2015)
[4] He Xiaohui, Zhou Chunze, Wang Haibo, Et al., Study on deformation characteristics of shield tunneling in upper soft and lower hard composite strata, Modern Urban Transit, 2, pp. 49-52, (2019)
[5] Zhang J, Ding L, Liang Y, Et al., Upper-bound finite element adaptive analysis of plane strain heading in soil with a soft upper layer and hard lower layer, Advance in Civil Engineering, 4, pp. 1-10, (2019)
[6] Chen Qiang, Study on support pressure at excavation face of shield tunneling in composite ground with soft and underlying hard strata, (2010)
[7] Li Kang, Limit support pressure of tunnel face and ground settlement analysis in rock-soil interface composite formations, (2017)
[8] Mollon G, Dias D, Soubra A H., Face stability analysis of circular tunnels driven by a pressurized shield, Journal of Geotechnical and Geoenvironmental Engineering, 136, 1, pp. 215-229, (2012)
[9] Leca E, Dormieux L., Upper and lower bound solutions for the face stability of shallow circular tunnels in frictional material, Geotechnique, 40, 4, pp. 581-606, (1990)
[10] Lyu Xilin, Wang Haoran, Huang Maosong, Limit theoretical study on face stability of shield tunnels, Chinese Journal of Geotechnical Engineering, 33, 1, pp. 57-62, (2011)

← 1 2 3 →