摘要
干湿循环作用对石窟砂岩影响严重,造成了大量石窟砂岩的悬臂拉裂式破坏.通过室内干湿循环试验、巴西劈裂试验以及应变场分析等方法,分析了不同干湿循环次数下试样的内摩擦角φ、粘聚力c、微观结构、以及应变场特征的变化规律.研究发现随着干湿循环次数的增加,粘土矿物逐渐流失,结构变得松散,矿物颗粒间的胶结作用减弱,导致了砂岩粘聚力c的减小.同时由于砂岩内部颗粒形状以及孔隙结构的变化改变了颗粒间的接触关系,导致了内摩擦角φ的减小,最终造成了其拉裂力学性质的劣化.最后结合试样的破坏过程及裂纹展布总结出了不同干湿循环作用下石窟砂岩的两种破坏模式.
The dry-wet cycle has a serious impact on the grotto sandstone,causing a large number of cantilever cracking damages to the grottoes.Through indoor dry-wet cycle test,Brazil split test and strain field analysis methods,the strength and mechanical parameters of the sample under different numbers of dry-wet cycles are analyzed and studied.The internal friction angle φ,cohesive force c,microstructure,strain field characteristics The law of change.The study found that with the increase of the number of dry-wet cycles,clay minerals gradually lost and the structure became loose.The weakening of the cementation between mineral particles led to the decrease of the cohesive force c of sandstone.At the same time,due to the change of the particle shape and pore structure of the sandstone,the contact relationship between the particles was changed,which led to the reduction of the internal friction angle φ,and finally caused the deterioration of its tensile and fracture mechanical properties.Finally,combining the failure process and crack distribution of the sample,two failure modes of the grotto sandstone under different dry-wet cycles are summarized.
作者
陈钊
兰恒星
刘世杰
都奎建
Chen Zhao;Lan Hengxing;Liu Shijie;Du Kuijian(School of Geological Engineering and Geomatics,Chang’an University,Xi’an 710054,China;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2024年第2期612-624,共13页
Earth Science
基金
国家重点研发计划(No.2019YFC1520601)
国家自然科学基金项目(Nos.42041006,41927806)。
关键词
岩石力学
干湿循环
石窟砂岩
抗拉强度
劣化机理
rock mechanics
wetting-drying cycles
grotto sandstone
tensile strength
deterioration mechanism
