摘要
侏罗系泥岩为河流相碎屑沉积岩层,大多呈紫红色、暗紫色和灰绿色,粉、细砂含量差异大,隐性裂纹发育,亲水性强,具有遇水崩解、软化、膨胀等工程特性。在现场地质观测基础上,开展了泥岩矿物鉴定和吸水性、崩解性、膨胀性试验以及单轴、三轴、载荷试验,全面测试和分析泥岩工程地质特性,结果表明:泥岩主要由54%~86%的泥质构成,因粉、细砂含量不同,崩解时间在1~3天不等;灰绿色泥岩属膨胀岩,具有弱膨胀性;砂质泥岩单轴抗压强度为泥岩的1.5倍,可作为泥岩和砂质泥岩压层划分依据;泥岩在加载过程中表现为弹性变形、弹塑性变形和宏观破坏3阶段,因层面影响其破坏模式,表现为非对称的剪切破坏特征,层面倾向的背侧压碎-剪切破坏特征明显;现场泥岩强度接近室内单轴强度的2倍,围压对泥岩强度影响极大。
Jurassic mudstone is clastic sedimentary rock of fluvial facies,mostly purple,dark purple and gray-green,with large differences in the content of powder and fine sand,hidden cracks developing,with strong hydrophilicity and engineering properties such as water disintegration,softening,and expansion.On the basis of on-site geological observations,mudstone mineral identification,water absorption,disintegration,and expansion tests,as well as uniaxial,triaxial,and load tests were carried out to comprehensively test and analyze the geological properties of mudstone engineering.The results showed that the mudstone is mainly composed of 54%to 86%of mud,and due to the different contents of silt and fine sand,the disintegration time varies from 1 to 3 days;Gray-green mudstone is expansive rock with weak expansiveness;The uniaxial compressive strength of sandy mudstone is 1.5 times that of mudstone,which can be used as the basis for the division of mudstone and sandy mudstone;Mudstone exhibits three stages of elastic deformation,elastic-plastic deformation and macroscopic failure during the loading process,and because the layer affects its failure mode,it is characterized by asymmetric shear failure,and the backside crushing—shear failure characteristic of layer tendency is obvious;The strength of the on-site mudstone is nearly twice that of the indoor uniaxial strength,and the confining pressure has a great influence on the strength of the mudstone.
作者
刘海军
何平
王新
刘蕴琨
邵江荣
任永辉
Liu Haijun;He Ping;Wang Xin;Liu Yunkun;Shao Jiangrong;Ren Yonghui
出处
《重庆建筑》
2022年第S01期497-500,共4页
Chongqing Architecture
关键词
侏罗系
泥岩
膨胀性
单轴强度
载荷试验
Jurassic
mudstone
expansiveness
uniaxial strength
load test
