Research on the effect of roof failure to the load-bearing characteristics of single pile penetrating karst cave
Wang Wei1,2,3 Nie Qingke2,3 Yuan Wei2,3,4 Wang Mengshu1 Liu Jingjing2,3
1. Beijing Jiaotong University, Beijing 100044, China
2. Hebei Research Institute of Construction & Geotechnical Investigation Co., Ltd., Shijiazhuang 050031, China
3. Technology Center of Geotechnical Engineering of Hebei Province, Shijiazhuang 050031, China
4. Shijiazhuang Tiedao University, Shijiazhuang 050043, China
Abstract：Single pile should be penetrated the karst cave into baseboard a certain depth to increase the bearing capacity if the roof thickness does not meet the safety requirements. Under the action of vertical load at the top of pile, the cave roof is likely to be in a state of tensile and even to be failure when the tension stress is beyond the tensile strength of roof, which will decrease the area of slide friction and damage the supporting effect that the roof provides to rock-mass above the roof. Thus, it is necessary to study the influence of roof tensile failure on the load-bearing characteristics of pile penetrating karst cave. In this paper, the roof failure modes are systematically studied through numerical simulation method considering different spans and height of karst cave, and the mechanical mechanism of tensile failure production and its influence rule on the slide friction of pile has been revealed. In addition, simplified mechanics analysis model for roof failure is established. At last, computing method of ultimate bearing capacity for the pile penetrating karst cave is proposed, which is used for providing technical guidance for the pile design and construction in the karst area.
王伟 聂庆科 袁维 王梦恕 刘晶晶. 溶洞顶板破坏对穿越溶洞型基桩极限承载力的影响规律研究[J]. 土木工程学报, 2017, 50(S1): 88-93.
Wang Wei Nie Qingke Yuan Wei Wang Mengshu Liu Jingjing. Research on the effect of roof failure to the load-bearing characteristics of single pile penetrating karst cave. 土木工程学报, 2017, 50(S1): 88-93.
