轴向静荷载下受频繁动力冲击时软/硬岩力学特性试验研究
Experimental study on mechanical properties of soft/hard rock under axial static load with frequent dynamic impact
投稿时间:2019-09-03  修订日期:2019-09-16
DOI:
中文关键词:  轴向静荷载  高应力  循环冲击  力学特性
英文关键词:Axial static pressure  Frequent impact  Energy dissipation  Mechanical properties.
基金项目:湖北省教育厅科研计划项目(编号:B2017555)。
  
作者单位
汪耀武 咸宁职业技术学院 建筑学院
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中文摘要:
      为了对比研究软岩和硬岩在轴向静荷载受频繁动力冲击作用下的力学特性,对取自冬瓜山铜矿的矽卡岩(硬岩)和大理岩(软岩)开展了动力冲击试验。试验结果表明:轴向静荷载对两种岩石累积冲击次数影响显著,累积冲击次数与轴向静荷载呈二次函数下降关系。大理岩和矽卡岩动态峰值应力均随冲击次数的增加而降低,矽卡岩动态峰值应力与冲击次数呈指数函数关系,大理岩动态峰值应力与冲击次数呈线性函数关系。随着冲击次数的增加,动态弹模整体呈下降趋势,矽卡岩在轴向静荷载为75MPa和90MPa时动态弹性模量呈现阶段性特征,并出现冲击疲劳期。大理岩动态弹性模量与矽卡岩在轴向静荷载为110MPa时的变化规律一致。矽卡岩在75MPa时,在冲击后期出现了吸收能量的现象,而在90MPa和110MPa时,整个冲击过程均为释放能量状态,而大理岩在冲击作用下均为吸收能量状态。
英文摘要:
      In order to study the mechanical properties of soft rock and hard rock under axial dynamic load with frequent dynamic impact, the dynamic impact test was carried out on skarn (hard rock) and marble (soft rock) which were taken from the Dongguashan copper mine. The test results showed that the axial static load has a significant effect on the cumulative impact times of the two types of rocks , and the cumulative impact times and the axial static load had a quadratic function. The dynamic peak stress of marble and skarn decreases with the increase of the number of impacts. The dynamic peak stress of skarn was exponentially related to the number of impacts. The dynamic peak stress of marble was linearly related to the number of impacts. With the increase of the number of impacts, the dynamic elastic modulus showed a downward trend. The dynamic elastic modulus of skarn showed a phase characteristic when the axial static load was 75 MPa and 90 MPa, and the impact fatigue period appeared. The dynamic elastic modulus of marble was consistent with that of skarn when the axial static load was 110 MPa. When the skarn was at 75 MPa, the energy absorption phenomenon occurs at the later stage of the impact. At 90 MPa and 110 MPa, the whole impact process was the energy release state and the marble was absorbed in the energy state under the impact.
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