饱水砂岩力学性质软化试验研究  

Experimental Study on Mechanical Property Softening of Water Saturated Sandstone

作　　者：赵立财 Zhao Licai(Stule Key Laborulory of Hlydrulic Enginering Simulation und Safely,Tiaryih Universily,Tianjin 30007,P.R.China;Department of Ciril and Construetion Engineering,National Taican Unirersity of Science and Technology,Taipei 10607,P.R.China;China Railuay 19th Bureau Group Co.,Ltd.,Beijing 100176,P.R.China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300354 [2]台湾科技大学营建工程系,中国台北10607 [3]中铁十九局集团有限公司,北京100176

出　　处：《地下空间与工程学报》2022年第1期154-162,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51879189);国家重点基础研究发展计划(973计划)(2014CB046803)。

摘　　要：地下硐室围岩在富水条件下强度弱化,对硐室开挖与营运造成威胁。为探究围岩在饱水作用下的力学性质及细观结构特征变化,开展了不同围压和饱水条件下的三轴压缩及扫描电镜试验。研究表明:(1)随着饱水作用的增强,砂岩力学性能不断衰减,当饱水天数达到30 d时,衰减幅度趋于平缓;(2)砂岩饱水劣化效应显著,峰值应力、黏聚力、内摩擦角、弹性模量和变形模量的劣化度累积规律较相似,饱水天数15 d以前累积较快,15 d以后累积速率放缓;(3)砂岩断口多表现为贝纹性状,以韧性破坏为主,围压对断口微裂纹发育起抑制作用,饱水作用促进微裂纹发育。研究成果为饱水作用下岩石力学性能劣化规律研究提供一定参考。The strength of the surrounding rock of the underground chamber is weakened under the condition of rich water, which threatens the excavation and operation of the chamber. In order to investigate the mechanical properties and microstructure of surrounding rock under water saturation, triaxial compression and SEM tests under different confining pressures and water saturation conditions were carried out. The results show that:(1) with the increase of saturation, the mechanical properties of sandstone are decreasing continuously, and the attenuation amplitude tends to be gentle when the saturated days reach 30 days.(2) the deterioration accumulation rule of the saturation deterioration of sandstone is relatively similar, the peak stress, cohesion, internal friction angle, elastic modulus and deformation modulus is similar, the saturated days accumulate faster before 15 days, and the accumulation rate is slowed after 15 days.(3) the fracture surface of sandstone is mainly composed of shell grain, mainly ductile failure, and confining pressure can inhibit the development of microcracks. The research results provide some reference for the study of the degradation law of rock mechanical properties under the action of water saturation.

关 键 词：饱水 砂岩 力学性质 软化 劣化度 断口 

分 类 号：TU452[建筑科学—岩土工程]