盐岩变形参数确定方法

为更加准确地确定盐岩变形参数,利用弹性力学理论推导出常规三轴压缩试验确定盐岩变形参数的计算公式。对某地下盐穴储气库区盐岩试样进行单轴、三轴压缩试验,对比分析两种试验方法获取的盐岩变形参数结果;并研究以单轴压缩试验为依据确定盐岩变形参数时,应力-应变曲线不同变形段的选择对变形参数的影响。结果表明:当采用初始弹性变形阶段的应力-应变增量求取盐岩变形参数时,利用三轴压缩试验方法所得到的结果更接近实际;以单轴压缩试验为依据确定的盐岩弹性模量及剪切模量与实际有较大误差,对应抗压强度5%~10%弹性变形段参数结果较10%~30%弹性变形段参数结果更为准确。研究成果可为合理确定盐岩变形参数提供参考依据。

A determination method for rock salt deformation parameters

In order to determine the deformation parameters of salt rock more accurately, the formula for calculating the rock salt deformation parameters determined by the conventional triaxial compression tests was deduced according to the elasticity theory. Uniaxial and triaxial compression tests were carried out on the rock salt specimen of one certain salt cavern underground gas storage. The deformation parameters obtained by two different test methods were comparatively analyzed. Furthermore, the influence of the selection of different deformation segments in the stress-strain curve on the deformation parameters was studied when determining the deformation parameters of salt rock on the basis of the uniaxial compression test. It is shown that when the stress-strain increment of initial elastic deformation stage is used to calculate the rock salt deformation parameters, the result obtained through triaxial compression test is much closer to actual value.There is a greater deviation between the elastic modulus and shear modulus of salt rock determined on the basis of uniaxial compression test and the actual values, and elastic deformation parameters corresponding to 5%-10% compressive strength are more accurate than those to 10%-30% compressive strength. The research results provide a reference for the reasonable determination of rock salt deformation parameters.