摘要
为实现矿井突水过程中岩层断裂和渗流通道形成过程的实时监测和前兆信息捕捉,将三维电阻率层析成像法作为一种实时成像监测手段尝试引入到矿井突水模型试验的监测工作中。采用具有自动采集功能的电阻率层析成像监测系统,实现介质电阻率变化数据的实时动态监测。提出优化反演效率的计算方法,利用Cholesky分解法求解电阻率层析成像正演中的大型线性方程组,利用预条件共轭梯度法求解反演方程,由此建立三维电阻率层析成像实时反演方法,实现原始数据的快速反演和动态图像的实时输出。提出以电阻率层析成像法为主,结合原始视电阻率数据分析和关键点数据时程曲线分析的多参数监测分析方法。在试验过程中,利用层析成像法得到防突层裂隙产生、扩展直至贯通的实时动态图像,得到主要裂隙和渗流通道的产生位置、形成过程等信息,与实际情况基本一致。综合3种方法的分析结果,得出防突层发生突水断裂的诱因,并确定捉到确切前兆信息的最早时,该时刻比突水发生时刻提前998s。模型试验证明,电阻率层析成像系统有效地反映岩层断裂及渗流通道的形成过程,成功地捕捉到一系列前兆信息,为突水灾害的及时预警预报提供重要参考。
For real-time monitoring of rock fracture and seepage channel formation and capturing of precursory information in process of mine water inrush, 3D electrical resistivity tomography（ERT） is applied to real-time monitoring work in mine water inrush model test. ERT monitoring system with automatic-acquisition function is used to implement real-time and dynamic monitoring work for resistivity variation. An optimization scheme for ERT inversion is proposed, in which Cholesky decomposition algorithm is used to solve large linear system in ERT forward modeling and preconditioning conjugate gradient（PCG） algorithm is used for inversion equation. Thus 3D ERT real-time inversion method is set up; to realized quick inversion of originally observed data and real-time output of dynamic images. In addition, a multi-parameter monitoring and analysis method is proposed, in which ERT is considered as a main means combined with analysis of originally apparent resistivity data and time-history curves for key points data. In the test process, dynamic images of crack generation, propagation and transfixion in aquifuge are obtained by ERT. The position and formation process of the major crack and seepage channel are also obtained, which are consistent with actual situation in the test. By comprehensive analysis of the results obtained with multi-parameter monitoring and analysis method, inducement of the fracture and inrush in aquifuge are gained. And the earliest time for capturing precursory information is obtained, which is 998 s ahead of inrush. The model test shows that the formation process of the crack and seepage channel is effectively reflected; and a series of precursory information is captured successfully by using ERT; and this system can give important reference to in-time early warming and prediction of inrush disaster.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2010年第2期297-307,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点基础研究发展计划(973)项目(2007CB209407)
国家高技术研究发展计划(863)项目(2007AA11Z131)
国家自然科学基金专项基金项目(50727904)
西部交通建设科技项目(2009318000008)
