RESEARCH on stability of cave roof under pile loading in bridge construction engineering
WANG Huabin1，2，LIU Zhifeng3，ZHAO Wenfeng1，2，ZHOU Bo1，2，LI Jiwei1，2
(1. School of Civil Engineering and Mechanics，Huazhong University of Science and Technology，Wuhan，Hubei 430074，China； 2. Hubei Key Laboratory of Control Structure，Huazhong University of Science and Technology，Wuhan，Hubei 430074，China； 3. Guangdong Provincial Changda Highway Engineering Co.，Ltd.，Guangzhou，Guangdong 510620，China)
Abstract：The present research is focused on the cave roof safety thickness and stability under pile loading in karst areas. Through the analysis of the interaction between the cave roof and pile foundation，four models were introduced to be as simply-supported，clamped circular plates and rectangular plates. Firstly，the force characteristics of cave roof under pile load in karst areas were analyzed. Based on the method of elasticity mechanics and introduction of Hoek-Brown criterion，a variety of simplified models were selected under consideration of the interaction between pile and cave roof. The maximum stress of the roof was then induced for different models following the theory of elastic mechanism. After the induction of the maximum stress，the theoretical formula of safety thickness was obtained，including the cases of four simplified models and anti-punching，shearing. Within the analysis of the stability for the cave roof，an equivalent conversion method for parameters was employed from the Hoek-Brown criterion to the Mohr-Coulomb criterion. In addition，compressive，tensile strength and other calculation parameters of the pile were determined，based on Hoek-Brown criterion，according to the detailed geological data of the West River Bridge. The cave roof thickness of different simplified models under different load conditions were then calculated by the theoretical formula. Using the finite element method，the theoretical results were identified to be the same as data from the numerical simulation. The results show that，it was feasible and effective to use the Hoek-Brown criterion to determine the stability of cave roof. Meanwhile，the results can be included in the national guideline for the design of piles in the bridge engineering in Karst areas.
汪华斌1，2，刘志峰3，赵文锋1，2，周 博1，2，李纪伟1，2. 桥梁桩基荷载下溶洞顶板稳定性研究[J]. 岩石力学与工程学报, 2013, 32(s2): 3650-3657.
WANG Huabin1，2，LIU Zhifeng3，ZHAO Wenfeng1，2，ZHOU Bo1，2，LI Jiwei1，2. RESEARCH on stability of cave roof under pile loading in bridge construction engineering. , 2013, 32(s2): 3650-3657.
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2013, Vol. 32 
