摘要
为研究酸性环境中砂岩在干湿循环作用下强度的劣化规律,在溶液p H值分别为7、5、3的浸泡环境中,对砂岩试样进行循环次数为1、5、10、15、20次的干湿循环试验。根据每个循环阶段后的强度数据,得到Mohr-Coulomb强度准则参数和Hoek-Brown强度准则参数,并对这些参数的干湿循环劣化效应做简要的分析。再根据应力空间中偏应力与强度准则参数的关系式,分别作出p H值为7、5、3的浸泡溶液作用下π平面上的破坏面随不同循环次数的变化图。结果表明:各准则参数随着干湿循环次数的增加呈下降趋势,循环次数较小时劣化较为严重,而后呈缓和趋势;p H值越低,劣化越严重,劣化效应由大至小依次为:单轴抗压强度、黏聚力、材料常数、内摩擦角;同一p H值浸泡环境中,循环次数较小时,π平面上的破坏曲线较为稀疏,循环次数越大,破坏曲线越密集;不同p H值浸泡环境中,p H越低,破坏曲面越小;偏应力与单轴抗压强度、黏聚力正相关,与材料常数、内摩擦角负相关。
To investigate the deterioration rule and failure criterion of rock in the acid-based environment, experiments were conducted on sandstone specimens after 1, 5, 10, 15, and 20 times of wetting and drying cycles in the environment of p H=7, 5 and 3, respectively. By analysing uniaxial compressive strength（UCS） and triaxial compressive strength（TCS） after different cycles, the parameters of Mohr-Coulomb failure criterion and Hoek-Brown failure criterion were calculated, and the effect of wetting and drying cycles on these parameters is also analysed. Finally, according to the relationship formula between the deviatoric stress and the strength criterion parameters in the stress space, the failure envelopes changed with cycles in the π-plane were drawn under the action of solutions with p H values of 7, 5, and 3. The results show that the parameters of strength criterion decrease with the increase of cycle time, at the early stage of cycles, the deterioration is more significant, and then the deterioration is relatively low. The lower the p H value is, the more serious the deterioration is, and the degrees of deterioration effect from large to small are as follow UCS, cohesion, material constant and internal friction angle. In the same environment of p H value, when the cycle number is low, the failure envelopes in the π-plane are relatively sparse. However, the greater the number of cycles are, the denser the failure envelope is; in the different immersion environment of p H value is, the lower the p H value is, the smaller the failure plane is. The deviatoric stress is positively correlated with UCS and cohesion, but negatively correlated with the material constant and internal friction angle.
作者
傅晏
袁文
刘新荣
缪露莉
谢文博
FU Yan;YUAN Wen;LIU Xin-rong;MIAO Lou-li;XIE Wen-bo(Faculty of Construction Management and Real Estate,Chongqing University,Chongqing 400045,China;Center for Construction Economics and Management,Chongqing University,Chongqing 400045,China;Bureau of Public Works of Shenzhen Municipality,Shenzhen,Guandong 518000,China;College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of Ministry of Education,Chongqing University,Chongqing 400045,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2018年第9期3331-3339,共9页
Rock and Soil Mechanics
基金
国家自然科学青年基金项目(No.51308567)
中央高校基本科研业务费(No.106112017CDJXY030012)~~
关键词
干湿循环
砂岩
劣化
π平面
破坏准则
wetting and drying
sandstone
deterioration
π-plane
failure criterion
