中文摘要：

选取中粗粒花岗岩,应用声发射技术,通过施加不同侧向压力,对双轴加载方式下花岗岩试样破裂过程中的声发射序列特征进行研究,着重分析了抗压强度、声发射活动特征与侧向压力的关系。研究表明：侧应力增大了竖向抗压强度,加载端临界侧向应变是侧向应力影响竖向抗压强度的关键。当加载端临界侧向应变为正值,即试件在该方向受拉时,侧向应力对竖向抗压强度的增强起到正作用;反之,起负作用。同时,侧压力对声发射序列特征影响也比较明显。侧压力较小时,岩石在加载初期只有较少的声发射事件,在破坏前出现大量的声发射事件,声发射序列在应力峰值前表现为单峰型;侧应力较大时,较小的应力扰动即可诱发微裂隙的产生和发展,产生较多的声发射事件,致使声发射序列表现为群震型。这对于岩石破裂失稳预报很有意义。

英文摘要：

With the use of grained granite as samples,the acoustic emission technique was used to investigate AE characteristics in failure process of granite rock samples under biaxial loading condition by applying different lateral stress,and emphasized the relationship of compressive strength,acoustic emission activity and lateral pressure.The results showed that the lateral stress increases the vertical compressive strength.The critical lateral strain at the loading end is the key factor that the later stress affects the vertical compressive strength.When the critical lateral strain at the loading end turns positive that sample experiences tension in the direction,the lateral stress plays a positive role in the increase of vertical compressive strength,otherwise is negative.Also,the lateral stress impacts on the acoustic emission sequence obviously.When the lateral stress is low,few acoustic emission events occur during the initiation of rocks loading.But as a large amount of acoustic emission events occur near failure,the acoustic emission sequence before stress peak shows up as the unimodal type.When the lateral stress is high,even a small stress disturbance may induce the generation and expansion of cracks that results in the acoustic emission sequence showing up as the cluster type,that have a great significance to forecast the rock failure.