岩石三轴应力试验及其压实效应规律研究

对深部地层5种有代表性的岩石(砂岩、灰岩、白云岩、石膏、花岗片麻岩)应力进行了三轴试验,测得了不同条件下岩石的声波速度、抗压强度和杨氏模量。利用回归分析法,建立了5种岩石的力学性质和声学性质随围压变化的数学模型。研究结果表明,对于同一种岩石,埋藏深度(围压)不同,其力学和声学特性也有很大差别。钻头对岩石的破碎效应除了受岩性的制约外,因埋深而产生的压实效应也对其有重要的影响。

Triaxial stress test of rock and primary research on the rule of compaction effect

The triaxial stress tests for five kinds of representative rock samples including sandstone, limestone, dolomite, salt lime and granite-gneiss were carried out. The acoustic velocity, compressive strength and the Young's modulus of the rock samples under different conditions were obtained. The mathematical models for the five kinds of rock samples were established on the regression analysis. The model was used to describe the relationship among the mechanical property, acoustic property and the confining pressure. The researched results show that the mechanical property and the acoustic property of rocks are much distinct under different embedding depth. Except for the lithology of rocks, the shattering effect of drill bits is restricted by the compaction effect relative to the embedding depth.