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梯度应力条件下隧道轴向应力对围岩力学响应及破裂特性的影响 被引量:1
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作者 赵宏刚 张东明 +1 位作者 蒋长宝 李铭辉 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第3期912-929,共18页
深埋地下工程的开挖导致隧洞径向方向围岩内部存在梯度应力。基于此,本文研究了梯度应力条件下围岩在不同轴向应力作用下的力学响应和断裂特征,并且在试验过程中,采用声发射(AE)系统采集了岩石破裂声发射信号。结果表明:梯度应力作用下... 深埋地下工程的开挖导致隧洞径向方向围岩内部存在梯度应力。基于此,本文研究了梯度应力条件下围岩在不同轴向应力作用下的力学响应和断裂特征,并且在试验过程中,采用声发射(AE)系统采集了岩石破裂声发射信号。结果表明:梯度应力作用下,轴向应力对砂岩力学响应的影响与经典真三轴压缩试验结果相似。当轴向应力小于临界强度时,随着轴向应力的增大,砂岩特征应力逐渐增大,显著提高了砂岩承载能力。但是当轴向应力超过临界强度时,高轴向应力的加载过程会导致砂岩产生局部破坏,引起砂岩特征应力的降低,此时,砂岩内部仅有部分裂纹合并贯通,形成斜向宏观裂隙,但并未贯穿整个砂岩试样。声发射特征信号分析结果表明,随着轴向应力的增大,砂岩在破坏过程中产生的剪切裂纹比例逐渐减小,拉伸裂纹在整个新生裂纹中占据主导地位,并控制着砂岩的破坏。这反映了在梯度应力条件下,随着轴向应力的增大,围岩内部因微观拉伸裂纹合并而形成宏观剪切裂纹的活动会受到明显的抑制作用。 展开更多
关键词 梯度应力 轴向应力 声发射 特征应力 拉伸裂纹
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A three-dimensional matching localization algorithm based on helix triangular pyramid array
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作者 ZHAO Jiu-bin LIU Yuan-xue +1 位作者 LIU Chang-jia LING Yue 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第3期816-833,共18页
On the eve of the occurrence of geological hazards,part of the rock and soil body begins to burst,rub,and fracture,generating infrasound signals propagating outward.3D advanced positioning of the landslide has remaine... On the eve of the occurrence of geological hazards,part of the rock and soil body begins to burst,rub,and fracture,generating infrasound signals propagating outward.3D advanced positioning of the landslide has remained unsolved,which is important for disaster prevention.Through the Fourier transform and Hankel transform of the wave equation in cylindrical coordinates,this work established a three-dimensional axisymmetric sound field model based on normal waves,and designed a 4-element helix triangular pyramid array with vertical and horizontal sampling capabilities.Based on this,the three-dimensional matching localization algorithm of infrasound for geological hazards is proposed.Applying the algorithm to the infrasound signal localization of rock and soil layers,it was found that the helix triangular pyramid array can achieve accurate estimation of depth and distance with a smaller number of array elements than the traditional array,and may overcome the azimuth symmetry ambiguity.This study shows the application prospects of this method for predicting geohazards position several hours in advance. 展开更多
关键词 geologic hazards INFRASOUND helix triangular pyramid array 3D matchinglocalization algorithm
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