不同加载速率下砂岩渗透率演化规律研究  

Study on Evolution Laws of Sandstone Permeability under Different Loading Rates

作　　者：高飞[1] 冯子军[1] 高阳 沈永星 GAO Fei;FENG Zijun;GAO Yang;SHEN Yongxing(College of Mining Technology,Taiyuan University of Technology,Taiyuan,Shanxi 030024,Chin)

机构地区：[1]太原理工大学采矿工程,山西太原030024

出　　处：《矿业研究与开发》2018年第7期52-55,共4页Mining Research and Development

基　　金：国家自然科学基金项目(51404161,51574173,51504220).

摘　　要：利用自主研制的伺服控制三轴岩石力学试验机,研究了砂岩在0.01~1μm/s不同加载速率下全应力应变过程中的渗透特性演化规律。结果表明:不同加载速率下砂岩渗透率随应变增加存在阈值渗透率、拐点渗透率和峰值渗透率,对应的应变为阈值应变、拐点应变和峰值应变;不同加载速率下,砂岩渗透率曲线变化趋势基本一致,即砂岩渗透率随应变变化呈现阶段性,初始应变至阈值应变为第一阶段,渗透率随应变增加不断降低,阈值应变至拐点应变为第二阶段,渗透率随着应变的增加缓慢增加,拐点应变至峰值应变为第三阶段,渗透率在该阶段内迅速增加,直至达到最大值;峰值应变之后是第四阶段,该阶段内渗透率随应变增加而略微降低;随加载速率从0.01μm/s增加至1μm/s,拐点应变之后的渗透率随加载速率增加而降低。The evolution laws of sandstone permeability under complete stress-strain process and the loading rates from 0.01μm/s to 1μm/s were studied by self-development servo-controlled machine for triaxial test of rock mechanics. The results indicated that under different loading rates, sandstone permeability ratepresented critical permeability, inflection point permeability and peak permeability with the increase of strain variation, relating to critical strain, inflection point strain and peak strain, respectively. Under different loading rates, the curve change trend of sandstone permeability were basically the same, namely the change of sandstone permeability with the stain showed stages. The first stage was from initial strain to critical strain, in which the permeability rate decreased with the increasing strain. The second stage was from critical strain and inflection point strain, in which the permeability rate slightly increased with the increasing strain. The third stage was inflection point strain to peak strain, in which the permeability rate rise shapely until reached the maximum value. Finally, the fourth stage was after the peak strain, in which the permeability rate slightly decreased with the increase of strain. The permeability after inflection point strain decreased with increasing loading rate ranging from 0.01μm/s to 1μm/s.

关 键 词：砂岩 渗透率 加载速率 三轴压缩试验 

分 类 号：TD315[矿业工程—矿井建设]