层状盐岩力学和变形特性数值试验研究

对含泥岩夹层层状盐岩力学和变形特性进行有限元分析。首先，用数值试验方法预测含泥岩夹层层状盐岩体宏观等效弹性力学参数，然后，建立层状盐岩复合体细观有限元模型，研究其在单轴和三轴压缩荷载下盐岩、泥岩以及界面细观应力应变场分布特征、应力集中问题，并将上述研究与已有的理论和试验成果进行对比。结果表明，运用细观有限元方法预测层状盐岩宏观弹性力学参数是一种直观有效的方法；泥岩和盐岩力学特性上的不匹配导致在层状盐岩的泥岩夹层中以及界面边缘处存在较为明显的应力集中和差异变形。单轴压缩时，泥岩体由于侧向变形能力差会受到横向拉伸应力作用而盐岩层则相应的受到横向压应力作用，三轴压缩时因围压和偏应力大小不同层状盐岩细观应力应变场分布特征则更为复杂；此方法能更为直观的分析层状盐岩的变形和破损特征，这一分析结果对进一步进行层状盐岩体内油（气）储库硐室稳定性分析提供了理论基础。

Numerical experiment study of deformation and mechanical properties of layered salt rock

Numerical simulation with finite element method is adopted to analyze deformation and mechanical properties of layered salt rock. Firstly, with numerical experiment method, macro-equivalent elastic-mechanics parameters of layered salt rock with mudstone interlayers are predicted; and then a micro-finite element model of layered salt rock is established; micro-stress and strain distribution and stress concentration are studied under uniaxial and triaxial loadings. The above numerical simulation is compared with the corresponding experimental and theoretical study. The results show that the micro-finite element method, an effective method, can forecast the macro-mechanics properties of layered salt rock; the mechanical properties mismatch of two adjacent layers results in obvious stress concentration and differential deformation at the interlayer and interface; an equivalent tension stress is applied on the stiffer interlayer and correspondingly an equivalent compression stress is applied on the weaker salt rock under uniaxial loadings. While under triaxial compression, micro-stress and strain distribution of layered salt rock is complicated under different confining pressures and deviator stresses. The present study can intuitively analyze deformation and failure characteristics; it also provides a theoretical basis for further study of the stability of the oil/gas storage cavern in layered salt rock formation.