考虑自愈合效应的泥岩巷道开挖扰动区渗透性反演分析  

Inversion analysis of permeability coefficients of excavation-disturbed zone around a mudstone roadway with considering self-healing effect

作　　者：贾善坡[1,2] 龚俊[1] 高敏[1] 罗金泽[1] 于洪丹[2] 

机构地区：[1]长江大学岩土力学与工程研究中心,湖北荆州434023 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩土力学》2015年第5期1444-1454,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金资助(No.41102182);湖北省自然科学基金资助(No.2011CDB008);中国博士后科学基金资助(No.2014M551055);岩土力学与工程国家重点实验室开放基金(No.Z013007)

摘　　要：泥岩自愈合特性是核废料库选址评价及储库安全稳定性分析的一项重要研究内容。以某泥岩高放废物处置库为研究背景,在室内和现场试验的基础上,采用指数模型建立了巷道围岩渗透性分布模型和裂隙渗透性自愈合模型;结合巷道围岩孔隙水压力的多年观测资料,通过建立能够反映实际施工过程的水-力耦合计算模型,采用精确罚函数法以及Nelder-Mead算法相结合的有限元优化反分析程序,对巷道围岩渗透性参数进行反演研究。结果表明:反演所得的围岩渗透系数量级与试验值量级均为10-12m/s,反演孔隙水压力值与实测值比较接近;围岩垂向渗透系数的扰动程度和范围明显大于水平向渗透系数,垂向渗透系数提高了2个数量级,扰动范围约为25 m,渗透性恢复到初始水平时间约需5 a。The self-healing behavior of mudstone is an important topic, which has to be addressed in site assessment and stability analysis for the nuclear waste repository. With a high-level radioactive waste repository in mudstone as background, the laboratory experiments and field tests are performed, and the distribution model and self-healing model of permeability are developed with introducing a decaying exponential function. Based the long-term field monitoring data of excavation-disturbed zones, a hydromechanical （HM） coupling model, which can describe construction and excavation processes, is developed and implemented into a finite element code for the optimization analysis of the permeability coefficient, with combining a new exact penalty function and the Nelder-Mead algorithm. The permeability coefficients of the excavation-disturbed zone around a waste repository are studied using the proposed procedure. The results show that the permeability coefficients from both the inversion analysis and the measurements have the same magnitude of 10 12 m/s, and the calculated pore pressures are also very close to the measured data. The vertical permeability coefficient is disturbed by excavation more significantly compared to the horizontal permeability coefficient with regard to both the intensity and the extent, and indeed the magnitude of the vertical permeability coefficient is increased by 2 orders, while the disturbed area is about 25 m. The self-healing time is about 5 years.

关 键 词：泥岩 开挖扰动区 自愈合 渗透性演化 反演 

分 类 号：TU452[建筑科学—岩土工程]