岩块尺度对摆型波传播影响研究

STUDY EFFECT OF BLOCK-ROCK SCALE ON PENDULUM-TYPE WAVE PROPAGATION

基于深部非连续自应力岩体介质的等级块系构造理论,研究块系岩体不同等级尺度对摆型波传播的影响。对冲击载荷作用下块系岩体介质动力模型进行求解得到各岩块的加速度响应。计算在相同的冲击能下,不同等级尺度块系岩体中,各岩块加速度及相应的频域特性包括频域曲线中心频率和中心频带宽度。通过比较得出,块系岩体等级越高,在冲击扰动下块体加速度衰减越快且衰减区域主要集中在初始端块体,同时相比于纵波和横波在块系岩体介质中传播的摆型波是一种低速波且块系岩体等级越高波速越低;块系岩体等级越高初始端岩块中心频率越大、中心频带宽度越宽,随着摆型波的传播块体中心频率向低频移动,中心频带宽度逐渐缩小表现出低频波的特性,且等级越高这种变化趋势越明显。借助于时域和频域内的分析结果和相应的测试技术,有助于反演岩体的破碎程度和节理的发育情况。

Based on the grade blocks tectonic theory for discontinuous and self-stress rock mass in depth,the effect of block-rock hierarchy scale on pendulum-type wave propagation is studied.Acceleration response of every block-rock is solved in the block-rock dynamical model on shock loading.Acceleration and frequency characteristics including center frequency and center frequency bandwidth of the block-rock mass are calculated,under the same shock loading energy and different block-rocks scales.The comparison results show that,the higher grade of block-rock structures,the more fast attenuation of block-rock mass acceleration on shock loading,and the main attenuation area is focus on the initial area of the block-rock structures.Pendulum-type wave is a low velocity wave while propagation in the block-rock mass compared with P wave and S wave.The higher grade of block-rock structures,the more lower velocity of pendulum-type wave.Block-rock with a larger frequency band center and wider bandwidth concentrate in the initial area when the higher grade of block-rock structures.The block-rock frequency band center moving to low frequency and the bandwidth becomes smaller on pendulum-type wave propagation,which performance the characteristics of low frequency,however,the changing trend more significantly when the higher grade of block-rock structures.Degree of fragmentation and joint development in rock mass can be inversion by the time-domain and frequency-domain results and testing techniques.