分级卸荷速率下软砂岩破坏特征试验研究  

EXPERIMENTAL STUDY ON FAILURE CHARACTERISTICS OF SOFT SANDSTONE UNDER GRADED UNLOADING RATE

作　　者：官少军 张磊 张高健 张聪 Guan Shao-jun;Zhang Lei;Zhang Gao-jian;Zhang Cong

机构地区：[1]中建二局第三建筑工程有限公司,北京100070

出　　处：《建筑技术开发》2023年第11期99-101,共3页Building Technology Development

摘　　要：山坡开挖活动是山体高坡释放轴向应力及环向应力的主要因素,根据开挖卸荷理论及卸荷岩体力学的思想相结合,某软砂岩山体边坡的地理环境下,采用三轴分级卸荷试验系统开展卸荷试验。考虑到山体边坡开挖过程中,山体边坡上覆荷载变化较小,侧向约束力受限的受力特征,确定轴向压力恒稳与环向压力逐级减小的卸载形式。结合山体边坡工程分层开挖方式与诱导原状岩体应力释放,存在不同强度分荷状态下量态分级的现象,考虑分级卸荷速率下软岩体的应力应变曲线,分析复杂边坡地形破坏状态下瞬态应变情况。Hillside excavation is the main factor to release axial stress and circumaxial stress on high slopes of mountains.According to the combination of excavation unloading theory and unloading rock mass mechanics,a triaxial grading unloading test system was used to carry out unloading tests under the geographical environment of a soft sandstone slope.Considering that the overlying load of mountain slope changes little and the lateral binding force is limited during the excavation process,the unloading form of axial pressure constant stability and circumaxial pressure decreasing step by step is determined.Combined with the layered excavation method of mountain slope engineering and the induced stress release of undisturbed rock mass,there exists the phenomenon of state classification under different strength load distribution states.Considering the stress-strain curve of soft rock mass under the graded unloading rate,the transient strain condition under the failure state of complex slope topography is analyzed.

关 键 词：岩体边坡开挖 分级卸荷岩体 瞬态应变 

分 类 号：TU74[建筑科学—建筑技术科学]