西北地区冻结岩石力学特性及爆破损伤评价模型试验研究

发布时间：2018-04-20 13:35

本文选题：冻结岩石 + 微观结构　；参考：《中国矿业大学（北京）》2014年博士论文

【摘要】：为了研究爆破作用下冻结岩壁的损伤分布规律，对实际采用冻结法爆破掘进的矿井围岩进行了微观结构分析，得到了西北地区典型岩石的微观结构特性。通过三轴试验，找出了冻结岩石强度与围压的关系。通过对典型岩石的低温蠕变试验找到了加速蠕变的门槛值，并建立红砂岩蠕变的本构模型。通过SHPB压杆试验得到了冻结红砂岩动态强度与应变速率之间的关系。利用相似理论设计了模型试验，对低温模型进行爆破掘进，在适当的部位安置三个速度传感器，测的各点的振动时程曲线，借助萨道夫斯基公式进行回归，得到了两个参数K、α，进而得到了任意位置处的振动速度。通过在模型中预埋超声波探测管，分别在爆破前、第一次爆破后、第二次爆破后、第三次爆破后测量模型各个测试面的波速，得到了模型在爆破作用下的损伤分布规律。在模型内部适当部位预先埋置应变砖，通过动态电阻应变仪得到了测点应变的时程曲线，找到了岩石应变与等效距离之间的对应关系。
[Abstract]:In order to study the damage distribution of frozen rock wall under the action of blasting, the microstructure of surrounding rock of mine excavated by freezing blasting is analyzed, and the microstructure characteristics of typical rock in Northwest China are obtained. The relationship between strength and confining pressure of frozen rock is found by triaxial test. The threshold value of accelerated creep is found through creep tests of typical rocks at low temperature, and the constitutive model of creep of red sandstone is established. The relationship between dynamic strength and strain rate of frozen red sandstone was obtained by SHPB compression bar test. The model test was designed by using the similarity theory, the low-temperature model was excavated by blasting, three velocity sensors were placed in the appropriate position, the vibration time history curve of each point was measured, and the regression was carried out with the aid of the Sadolski formula. Two parameters K, 伪 are obtained, and the vibration velocity at any position is obtained. The wave velocities of each test surface of the model were measured before blasting, after the first blasting, after the second blasting and after the third blasting, respectively. The damage distribution law of the model under blasting action was obtained. In the proper part of the model, the time-history curve of the strain of the measuring point is obtained by means of dynamic resistance strainer, and the corresponding relationship between the strain of rock and the equivalent distance is found.
【学位授予单位】：中国矿业大学（北京）
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU45

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