Application of upper bound method for basal stability analysis in practice
QIN Hui-lai1, 2, HUANG Mao-song3, 4
1. Key Laboratory of Road Structure and Material of Ministry of Transport, Research Institute of Highway Ministry of Transport, Beijing 100088, China; 2. Technical Center, China State Construction Engineering Corporation, Beijing 101300, China; 3. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 4. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China
Abstract：It is a good choice for applying the multi-block upper bound method to the stability analysis of geotechnical problems. This method is simple, highly effective and based on rigorous theory basis. The multi-block upper bound method is used to solve the basal stability of deep excavations. According to the disciplines in China, the consolidated-undrained strength parameters are always employed to design the excavations. Simplification is taken to apply the consolidated-undrained strength parameters to the calculation in the upper bound method. Several excavation cases are calculated by the multi-block upper bound method, and the results are compared with those of the bearing capacity method and the circular slip method. The reasonable criterion is discussed when the safety factor for basal stability analysis is obtained from the multi-block upper bound method.
[1] Canadian Geotechnical Society. Canadian foundation engineering manual[M] 4th ed. Richmond, BC: BiTech Publishers Ltd, Canada, 2006. [2] OU CHANG YU. Deep excavation: Theory and practice[M]. Balkema: Taylor & Francis Group, 2006. [3] TERZAGHI K. Theoretical soil mechanics[M]. New York: John Wiley and Sons, 1943. [4] BJERRUM L, EIDE O. Stability of strutted excavations in clay[J]. Géotechnique, 1956, 6(1): 115-128. [5] 刘国彬, 王卫东. 基坑工程手册[M]. 2版. 北京: 中国建筑工业出版社, 2009: 136-142. (LIU Guo-bin, WANG Wei-dong. Excavations engineering manual[M]. 2nd ed. Beijing: China Architecture and Building Press, 2009: 136-142. (in Chinese)) [6] CHANG M F. Basal stability analysis of braced cuts in clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 2000, 126(3): 276-279. [7] CAI F, UGAI K, HAGIWARA T. Base stability of circular excavation in soft clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2002, 128(8): 702-706. [8] 王卫东, 徐中华. 基于强度折减法的圆形深基坑坑底抗隆起稳定性分析[J]. 建筑结构学报, 2010, 31(5): 195-201. (WANG Wei-dong, XU Zhong-hua. Strength reduction approach for analyzing safety against basal heave of circular deep excavations[J]. Journal of Building Structures, 2010, 31(5): 195-201. (in Chinese)) [9] UKRITCHON B, WHITTLE A J, SLOAN S W. Undrained stability of braced excavations in clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2003, 129(8): 738-755. [10] 秦会来, 黄茂松, 马少坤. 黏土基坑抗隆起稳定分析的多块体上限解[J]. 岩石力学与工程学报, 2010, 29(1): 73-81. (QIN Hui-lai, HUANG Mao-song, MA Shao-kun. Multi-block upper bound method for basal heave stability analysis of braced excavation in clay[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(1): 73-81. (in Chinese)) [11] 秦会来, 陈祖煜, 刘立鹏. 基于上限理论的软土基坑抗隆起稳定分析方法[J]. 岩土工程学报, 2012, 34(9): 1611-1619. (QIN Hui-lai, CHEN Zu-yu, LIU Li-peng. Basal stability analysis for the excavations in soft clay based on the upper-bound method[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(9): 1611-1619. (in Chinese)) [12] CHEN W F. Limit analysis and soil plasticity[M]. Amsterdam: Elsevier Science, 1975.
