岩石力学第二份试卷
Section A Term Explaination术语解释
1. Brittle of rock 岩石的脆性
2. Shear strength of rock 岩石的剪切强度 3. In-situ stress 原(就)地应力 4. Fracture pressure破裂压力 5. Yoang’s modulus 杨氏模量 6. Principal stress主应力
Section B Brief Description简要描述
1. Describe the effective stress principle描述有效应力原理
2. Describe the influence of confining pressure on the deformation and strength characters of rock mechanics描述围压对岩石变形和强度特征的影响
3. Briefly describe the shear strength criterion of Coulomb-Vavier简要介绍Coulomb-Vavier抗剪强度准则
4. Describe Brazilian test steps and how to obtain the tensile strength of rock with it 描述巴西实验的步骤,以及如何用它获得岩石抗拉强度
Section C calculations计算题
1. In order to study the strength feature of an sandstone ,we select two samples to do the uniaxial compressive strength test .The test results are as follows: the uniaxial compressive strength is 60MPa, the peak strength is 120MPa with the confining pressure of 20MPa. Assuming the shear strength is agreed with Coulomb-Vavier criterion
Determine the cohesion and internal friction angle of the rock with Mohr’s circle method.
为了研究砂岩的强度特性, 我们选择两个样本做单轴抗压强度试验。测试结果如下:单轴抗压强度是60 MPa、峰值强度是120 MPa，围压20 MPa。假设抗剪强度符合Coulomb-Vavier准则, 用莫尔圆方法确定内聚力和岩石的内摩擦角
2. In an oil field ,well depth is 1000m, sandstone strength confirms to Mohre-Coulomb criterion. Its cohesion is 6.0MPa, its angle of internal friction is 45º, Poisson ratio is 0.25, uniaxial tensile strength is 2MPa. Overburden is 22.6MPa , minimum horizontal in-situ stress is 17MPa , maxmum horizontal in-situ stress is
23MPa , pore pressure is 12MPa .
Calculate the collapse pressure and fracture pressure , then determine the reasonal mud density window to open this formation . Notice: effective stress coefficient α=0.5.
一个油田,井深度为1000米,砂岩强度符合Mohre-Coulomb（摩尔-库仑）准则。其内聚力是6.0MPa, 其内摩擦角是45º, 泊松比为0.25,单轴抗拉强度是2MPa。上覆压力是22.6 MPa、最小水平地应力是17 MPa, 最大水平地应力是23 MPa，孔隙压力是12 MPa。
计算坍塌压力和破裂压力, 然后确定合理的泥浆密度窗口以钻进这套地层。 注:有效应力系数α= 0.5。
