地震作用下岩石裂纹扩展角度研究  

Research on rock crack propagation angle under earthquake action

作　　者：高丙丽[1] 曹孝杰 GAO Bingli;CAO Xiaojie(College of Civil and Architectural Engineering,Xi’an University of Science and Technology,Xi’an 710054,China)

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054

出　　处：《西安科技大学学报》2023年第5期980-987,共8页Journal of Xi’an University of Science and Technology

基　　金：国家重点研发计划项目(2019YFC1509703)。

摘　　要：为研究地震作用下岩石动态开裂的复杂问题,基于最大周向应力准则,考虑非奇异应力三分量及地震作用,推导出了适用于地震作用下的裂纹扩展角度判据;采用霍普金森拉杆试验结果对修正裂纹扩展角度判据可靠性进行验证,针对验证过程中样本数较少的情况,基于贝叶斯理论,开发了岩石领域小样本问题后验分布估计程序,并采用该程序进一步验证修正裂纹扩展角度判据的可靠性。结果表明:在霍普金森拉杆试验中,MCTS试样可以通过施加位移约束,实现可控模式复合比的复合型加载;最大周向应力判据、修正最大周向应力判据对霍普金森拉杆试验中的MCTS试样裂纹扩展角度预测值平均误差分别为1.6°、1.37°;以试验值、最大周向应力判据预测值、修正最大周向应力判据预测值为基础数据运行Gibbs算法分别进行十万次迭代,求得这三种情况下的裂纹扩展角度均值分别为50.64°、48.96°、49.45°,修正最大周向应力判据与最大周向应力判据相比,其预测误差由3.32%降低到了2.35%,表明其在地震作用下具有良好的适用性。研究对地震作用下的边坡危岩减抗震设计及其风险控制具有重要意义。In order to study the complex problem of dynamic cracking of rocks under earthquake action,a crack propagation angle criterion is derived based on the maximum circumferential stress criterion,with the non-singular stress triplet component and earthquake action in view.The posterior distribution estimation procedure for small sample problems in the domain is designed based on Bayesian theory,and the procedure is used to further verify the reliability of the modified crack propagation angle criterion.The results show that the MCTS specimens in split Hopkinson tension bar test can be loaded in a composite manner with controlled mode composite ratio by applying displacement constraints.The average errors of the predicted values of the maximum circumferential stress criterion and the modified maximum circumferential stress criterion for the crack propagation angle of MCTS specimens in split Hopkinson tension bar test are 1.6°and 1.37°,respectively.The Gibbs algorithm was run for 100000 iterations to obtain the mean values of 50.64°,48.96°and 49.45°for the crack propagation angles in these three cases,respectively,and the prediction error of the modified maximum circumferential stress criterion was reduced from 3.32%to 2.35%compared with that of the maximum circumferential stress criterion,which shows that it has good applicability under earthquake effects.The study is of great significance for the seismic design of slope hazardous rock and its risk control under seismic action.

关 键 词：地震作用 非奇异应力 裂纹扩展 霍普金森拉杆 贝叶斯理论 

分 类 号：TU452[建筑科学—岩土工程]