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

作　　者：汪耀武[1,2] WANG Yaowu(Academy of Architecture,Xianning Vocational and Technical College,Xianning 437100,China;School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]咸宁职业技术学院建筑学院,湖北咸宁437100 [2]郑州大学土木工程学院,郑州450001

出　　处：《有色金属工程》2020年第4期100-108,共9页Nonferrous Metals Engineering

基　　金：湖北省教育厅科研计划项目(B2017555)。

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75 MPa和90 MPa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110 MPa时的变化规律一致。矽卡岩在75 MPa时,在冲击后期出现了吸收能量的现象,但在90 MPa和110 MPa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。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 show 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 has an exponentially function with the impact times.The dynamic peak stress of marble has a linearly function with impact times.With the increase of impact times,the dynamic elastic modulus show downtrend.The dynamic elastic modulus of skarn show a phase characteristic when the axial static load is 75 MPa and 90 MPa respectively,and the impact fatigue period appeared.The dynamic elastic modulus of marble is consistent with that of skarn when the axial static load is 110 MPa.When the skarn is at 75 MPa,the energy absorption phenomenon occurs at the later stage of the impact while at 90 MPa and 110 MPa,the whole impact process is in the state of energy release.The marble is always in the state of energy absorption under the impact.

关 键 词：轴向静荷载 高应力 循环冲击 力学特性 

分 类 号：TD315[矿业工程—矿井建设]