MONITORING SYSTEMS AND PREVENTION TECHNOLOGIES FOR DEEP UNDERGROUND ENVIRONMENT

本课题针对地下环境问题进行了多方面的研究，取得了以下成果。首先，为了估计深层地下结构的性态，研究了P波在岩石裂隙中的传播特性，发现P波的均方根振幅与岩石裂隙的接触面积成正比，这一关系对于估计岩石裂隙的剪切过程是有用的。在此基础上，研制了声发射自动测量系统，并对某地下电站施工现场的围岩性态进行了评价。其次，为了开发地下环境监测系统，利用地质统计学方法对某隧道施工现场的坝址区地下水位分布和隧道工作面围岩性质进行了评价，得出地质统计学方法具有很强的…特性的结论对于这样的评估更有用。此外，还利用激光多普勒测振仪进行了超声传播的精确测量，为雷利波检测和超声波无损检测奠定了基础，得到了正确的声速-频散曲线。文中还讨论了速度-频散曲线的适用性。此外，还发展了电阻率、弹性波、超精密倾斜仪等精密物探技术，并将其应用于裂隙地下结构的调查。第三，为了开发一种使有毒物质无害、防止有毒物质扩散/渗透的技术，研究了井下物质运移对裂隙渗透率立方定律的偏离情况。此外，结合高放废物的地质处置，对海岸海床下的地下水流动进行了数值分析，明确了淡水和咸水边界的运动。在此基础上，提出了重金属污染泥质地基电动修复过程的数值分析方法，阐明了水力坡度修复对修复效果的促进作用。另一方面，从理论上探讨了动力注浆方法对低渗透岩体的影响，并提出了一种合理的应用方法。较少

In this project, several pieces of research were conducted to the problem of underground environment, and the following results were obtained. First, in order to estimate the behavior of a deep underground structure, propagation properties of P wave which transmits through a rock fracture were investigated, and it was cleared that the RMS amplitude of the P wave are directly proportional to the contact area of the rock fracture and this relation is useful to estimate the shear process of a rock fracture. Moreover, an automatic AE measurement system was developed and the surrounding rock mass behavior was evaluated at the construction site of an underground power station. Second, in order to develop a monitoring system for the underground environment, geostatistics was applied to evaluate the distribution of groundwater level around a dam site and the rock properties beyond a tunnel face at a tunnel construction site using a TBM, and it was concluded that geostatistics approach is very … More useful for such the evaluation. Moreover, a precise measurement of ultrasonic propagation using a laser Doppler vibrometer was carried out as a fundamental research for the Inspection by Reyleigh wave and the nondestructive inspection by ultrasonic wave, and correct ultrasonic velocity-dispersion curves were obtained. The applicability of the velocity-dispersion curve was also discussed. Furthermore, precise geophysical investigation technologies using resistivity, elastic wave, very precise tilt-meter, etc. were developed, and they were applied to the investigation of fractured underground structure. Third, in order to develop a technology which makes a toxic substance harmless and prevents the toxic substance diffusing/permeating, the deviation from the cube law of fracture permeability which governs the migration of substances in underground was investigated. Moreover, relating to geological disposal of high-level-radioactive-wastes, a numerical analysis for the groundwater flow under the coast seabed was performed and the movement of the boundary between fresh water and salt water was clarified. Furthermore, a numerical analysis method was proposed for the process of electrokinetic soil remediation to the argillaceous foundation polluted with heavy metal, and the promotion effect of the remediation with the hydraulic gradient was clarified. On the other hand, the effect of dynamic grouting method to a low permeable rock mass was discussed theoretically, and a rational method to apply this method was proposed. Less