基于波速测量的岩石储能量化表征方法研究

Research on Quantitative Characterization Method of Rock Energy Storage Based on Wave Velocity Measurement

为了定量化表征岩石储能,选择3类典型岩石(强度较低的红砂岩、中等强度的大理岩和坚硬的花岗岩),在弹性区间内对其压缩载荷(或应力)与纵波波速之间的随动关系进行测试研究,并根据其应力—应变特征曲线,计算出应力与存储能量之间的定量关系,建立以应力为桥梁的"波速—应力—储能"的定量化表征方法。结果表明:在3种典型岩石弹性阶段内,其纵波波速与压缩应力均呈现出明显的线性关系;压缩应力与岩石储能之间基本符合复合幂指数关系;根据卸载波速—应力、应力—弹性储能所建立的模型,可以得到卸载波速与弹性储能之间的对应函数关系,实现了用波速定量化表征岩石储能的目的,即获得了一种较为可行的用波速定量化表征岩石储能的测试技术方法。测试结果还表明:硬岩比软岩更适合采用此方法来定量化表征存储的能量,其精度和准确度更高。

The underground rock mass stores a large amount of energy,disasters such as rock bursts will occur under certain conditions.The benign application of rock energy storage can not only effectively reduce the sudden release of energy,but also make use of rock energy.But there are still a series of technical problems to be solved in order to make it work.One of the key issues is how to accurately quantify the energy storage of deep rock mass. This study only qualitatively and quantitatively studies the elastic range of rock,using low-intensity red sandstone(sedimentary rock),medium-strength marble(metamorphic rock)and high-strength granite(magmatic rock).The basic idea of this study is to explore the relationship between wave velocity and stress in the elastic phase of rock.The model is used to characterize the corresponding stress value by wave velocity,and then explore the relationship between stress and the corresponding energy density.The model uses stress to characterize the energy stored in the rock,and then compares the energy value obtained by the model with the actual energy value to verify the method of characterizing energy with wave velocity.The test results show that the longitudinal wave velocity and the compressive stress show a linear relationship in the three typical rock elastic stages,and the compressive stress and the rock energy storage basically conform to the complex power exponential relationship. The results also show that the theoretical value is not much different from the real value,the error is small,and the hard rock is more suitable than soft rock to be quantified the stored energy with this method,with higher precision and accuracy.In this paper,through the uniaxial repeated loading and unloading test and calculation of the typical rock specimens of marble,granite and red sandstone in the elastic range,the following conclusions are drawn:① The three waves exhibit wave velocity with increasing stress.However,when the stress is 30% of the maximum stress,the wave velocity growth of the three rocks is relatively uniform.When the stress exceeds 30% of the maximum stress,the growth rate of marble and granite is still consistent,while the rate of growth of red sandstone is steep.Increase the phenomenon.② The wave velocity and stress of the three rocks accord with the linear model. The accuracy of the red sandstone is lower than that of marble and granite.The total energy and elastic energy of the granite are larger than that of marble and red sandstone.The red sandstone has higher dissipative energy than marble and granite.③ According to the function of unloading wave velocity-stress and stress-elasticity,the wave velocity-elastic energy model is constructed and verified,the overall effect is better,and the accuracy and accuracy of hard rock are higher than that of soft rock.