摘要
针对冲切破坏模式下溶洞顶板极限承载力问题,进行了不同顶板厚度以及不同荷载偏心距下溶洞顶板极限承载力室内试验研究,依据试验结果将偏心荷载作用下的溶洞冲切破坏假定为轴对称问题,引入Griffith强度准则,基于极限分析上限法,提出了一种适用于轴对称和偏心荷载作用下溶洞顶底板极限承载力的计算方法,并给出了能发生冲切破坏范围的估算方法。试验结果表明:在同一偏心距下,随着顶板厚度的增加,在达到基岩极限承载力之前,顶板极限承载力呈线性增长;当顶板厚度一定时,顶板极限承载力随着偏心距的增加呈非线性增长,偏心距e在能发生冲切破坏的范围之外时趋于平缓,并逐渐达到基岩极限承载力;理论计算结果与试验结果吻合较好。
Under the punching shear failure mode, the experiments were conducted on the karst cave roof to study the bearing capacity under different roof thicknesses and load eccentricities in the laboratory. The failure mode of karst cave under eccentric loading was assumed to be axisymmetric according to the experimental results. Based on the upper bound limit analysis method and Griffith strength criterion, a new method was proposed for calculating the ultimate bearing capacity of karst cave roof both under axial symmetrical and eccentric loading. Besides, a method was given for estimating the range of the punching failure area. The experimental results show that at the same eccentric distance, the ultimate bearing capacity of the roof increases linearly with the increase of the roof thickness before reaching the ultimate bearing capacity of the bedrock. When the roof thickness is constant, the ultimate bearing capacity increases nonlinearly with the increase of eccentricity. In addition, the eccentricity e tends to be gentle and reaches the ultimate bearing capacity of the bedrock at the outside the range of punching shear failure. The theoretical calculation results are in good agreement with the experimental results.
作者
尹君凡
雷勇
陈秋南
刘一新
邓加政
YIN Jun-fan;LEI Yong;CHEN Qiu-nan;LIU Yi-xin;DENG Jia-zheng(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;Chongqing Municipal Research Institute of Design,Chongqing 400020,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2018年第8期2837-2843,共7页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51208195
No.41372303)
岩土工程稳定控制与健康监测湖南省重点实验室开放基金资助(No.E21618)~~
关键词
岩溶区
极限分析法
极限承载力
破坏模式
试验研究
karst area
limit analysis method
ultimate bearing capacity
failure mode
experimental study