脆性岩石扩容起始应力预测——以花岗岩和闪长岩为例

发布时间：2018-05-08 22:29

本文选题：岩石力学 + 扩容起始应力　；参考：《岩石力学与工程学报》2014年04期

【摘要】：采用TAW 2000电液伺服岩石三轴试验机,通过32组花岗岩和闪长岩的物性及单轴压缩试验测试,获得岩石的特征物理力学参数。在此基础上,揭示岩石扩容起始应力与弹性模量、泊松比和孔隙度的关系,建立花岗岩和闪长岩的扩容起始应力预测方程。研究结果表明:(1)弹性模量作为岩石的弹性基质刚度的反映,包括颗粒间的接触刚度和颗粒间基质的刚度,孔隙度作为岩石内部孔洞空间的体积测量指标,是岩石内初始的微裂纹、微孔洞及张开裂纹的综合反映,一定程度上可以反映初始损伤的程度,二者与岩石的扩容起始应力密切相关;(2)扩容起始应力与弹性模量呈正相关,而与孔隙度呈负相关,当弹性模量最小而孔隙度最大时对应最小的扩容应力值,反之调整;(3)通过逐步数据拟合分析得出扩容应力的预测模型,通过与试验结果的对比分析,证明预测模型的可靠性。在弹性模量、孔隙度和泊松比已知的前提下,可以先验地对扩容起始应力进行预测,为扩容起始应力的求解提供一条新的思路。
[Abstract]:The physical properties and uniaxial compression tests of 32 groups of granite and diorite were tested with TAW 2000 electro-hydraulic servo rock triaxial testing machine. The characteristic physical and mechanical parameters of rock were obtained. On this basis, the relationship between initial expansion stress and elastic modulus, Poisson's ratio and porosity of granite and diorite is revealed, and the prediction equation of initial expansion stress of granite and diorite is established. The results show that the elastic modulus is the reflection of the elastic matrix stiffness of rock, including the contact stiffness between particles and the stiffness of matrix between particles, and the porosity as the volume measurement index of the pore space in rock. It is the initial microcrack in rock. The comprehensive reflection of micropore and open crack can reflect the degree of initial damage to a certain extent, and they are closely related to the initial stress of rock expansion and have a positive correlation with the initial stress of expansion and modulus of elasticity. When the modulus of elasticity is the smallest and the porosity is the largest, the minimum expansion stress is corresponding to that of the porosity. On the contrary, by the stepwise data fitting analysis, the prediction model of the expansion stress is obtained, and the results are compared with the experimental results. The reliability of the prediction model is proved. Based on the known elastic modulus, porosity and Poisson's ratio, the initial expansion stress can be predicted priori, which provides a new idea for the solution of the initial expansion stress.
【作者单位】：中国科学院地质与地球物理研究所工程地质力学重点实验室;中国科学院大学;
【基金】：国家重点基础研究发展计划(973)项目(2010CB731501) 国家自然科学基金资助项目(41227901,41272352)
【分类号】：TU45

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