基于学科交叉的岩体损伤监测实验教学

Experimental teaching of rock mass damage monitoring based on interdisciplinary

为解决传统岩体损伤监测中岩体内部损伤可视化的难题,基于学科交叉理念引入了地震学中的地震成像技术。分析了地震成像的原理、理论算法、实验过程和数据处理方法,详细阐述了地震成像技术在岩体损伤监测实验中有别于地震监测的细节问题。通过以室内受载岩石的损伤监测为实验教学案例,并将受载岩石内部的损伤进行可视化,揭示了荷载作用下岩石内部损伤的演化规律,弥补了传统岩体损伤监测的缺陷,启发了学生的学科交叉思维,引导他们关注并解决学科交叉过程中的部分“不兼容”问题。

[Objeetive]Rock damage monitoring in geotechnical engineering heavily relies on on-site engineering experience.Factors such as geological structure,environmental conditions,and human mining activities contribute to the variability in weak planes like joints and fractures within the rock masses.Even among rock masses with the same lithology,these features can differ significantly in occurrence and scale,leading to varying mechanical properties.This difference necessitates more sophisticated monitoring of rock damage and promotes integration with other disciplines.However,during the rapid infrastructure development over the past decade,the urgency of engineering projects has prevented many issues from being effectively addressed during interdisciplinary technology integration.This lack of resolution poses potential threats to the stability of rock masses.To address the challenge of visualizing internal damage in traditional rock mass damage monitoring,this study introduces seismic imaging technology from seismology based on the interdisciplinary background.[Methods]Taking the experimental study of damage evolution under uniaxial loads based on acoustic emission(AE)monitoring as an example,this research explores necessary modifications to techniques and theoretical algorithms when introducing seismic imaging methods for rock damage monitoring.It also provides detailed insights into distinguishing seismic imaging technology from seismology in the context of rock damage monitoring experiments.Eight AE probes were employed to monitor the rock fracture process under uniaxial loading and collect the AE waveform data.The first arrival of P-waves was picked to reduce errors.The imaging algorithm was then improved for small-sized rock specimens,reducing the time distribution constraint on the establishment of AE event pairs,thus enhancing the accuracy of the imaging results.Finally,the damage evolution within the rock showed a nonuniform distribution.[Results]The experimental results showed that during the initial loading stage,the primary pores in the rock were compacted and closed,resulting in an increase in the longitudinal wave velocity in some areas.Afterward,the longitudinal wave velocity inside the rock mainly decreased,with the growth rate peaking in the plastic deformation stage.In addition,during the entire process of rock loading,a few areas still exhibited an increase in longitudinal wave velocity.This is attributed to the isolation of cracks within the rock.[Conclusions]Based on interdisciplinary research,this study introduces seismic imaging technology from seismology into rock damage monitoring experiments.Compared with traditional methods,this approach considers the engineering reality of rock heterogeneity and enables three-dimensional visualization of the damage within the loaded rock mass.This provides new ideas for rock mass stability monitoring across several disciplines,such as civil engineering,mining engineering,geological engineering,water conservancy engineering,geotechnical engineering,and disaster prevention and reduction engineering.Taking damage monitoring of the rock under uniaxial load as an experimental teaching case,the damage of the loaded rock was successfully visualized,thereby revealing the damage evolution law.This approach compensates for the shortcomings of traditional rock damage monitoring that cannot visualize internal damage.It also inspires students’interdisciplinary innovation thinking,guiding them to explore and solve problems in the process of interdisciplinary technology integration.