摘要
对北京房山干、饱水砂岩在不同恒定应力、围压、空隙水压力和湿度下,进行了一系列三轴压缩或蠕变试验.发现对于各种湿度、围压、空隙水压力及加载时间下的loge<sub>d</sub>和σ<sup>*</sup>关系曲线的斜率在临界应力σ<sub>df</sub>（约为0.6～0.7σ<sub>F</sub>）处出现突然变化、因此,作者提议砂岩的扩容全过程可用一簇双线性曲线描述;并对每条曲线的直线以不同公式表示。还发现破坏强度σ<sub>F</sub>和扩容起始强度f<sup>*</sup>随着湿度增加和围压减小而不断减小,而对于不同围压下logσ<sub>F</sub>（或logf<sup>*</sup>）和log Sr/Sro关系线的斜率却几乎在相同的饱水度,约50％处,也出现突然变化.试验结果表明f<sup>*</sup>和σ<sub>F</sub>之间存在着单值关系,它并不取决于围压和饱水度,而弹性模量却与围压和饱水度密切相关.
A series of triaxial compressive or creep tests was conducted on Fang-Shan dry and saturated sandstones under various constant stresses, confining pressures, pore -water pressures and humidities. It is found that a sudden change occurred in the slope of log ed vs.σ* curves at a critical stress (about(0.6—0.7)σ_F)for various humidities, confining pressures, pore-water pressures and applied loading times. Therefore, the author suggests that the entire process of dilatancy of sandstones can be described by a family of bilinear curves, and different equations are presented for each line of curves. It has also been found that the failure strength σ_F and dilatahey onset strength f* consistently decreases with increasing humidity and decreasing confining pressure, but a sudden change occurred in slope of log σ_F(or log f*). log Sr/Sr0 curves at almost the same dearee of saturation (about 50％)for variou confining pressures. The test results indicate that there is a uniguerelationship between f* and σ_F, which is not dependent upon confining pressure and degree of saturation, whereas the elastic modulus is closely related to both confining pressure and degree of saturation.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
1990年第3期184-194,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金
