Back-analysis approach for the determination of hydraulic conductivity in rock caverns

• Main Authors: Xu, Zhipeng, Zhao, Zhiye, Sun, Jianping, He, Lei, Nie, Wen
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2015
• Subjects: DRNTU::Engineering::Civil engineering::Construction technology
• Online Access: https://hdl.handle.net/10356/107265; http://hdl.handle.net/10220/25407; http://dx.doi.org/10.1016/j.tust.2015.01.008
• Institution: Nanyang Technological University

Water seepage related problem is often the major geological hazard in underground rock excavation. In order to reduce the risk associated with extensive seepage, a reliable hydro-geological model should be established based on the in-situ investigation data. One of the challenges for establishing a reliable hydro-geological model is on how to determine the hydraulic conductivities of the fractured rock masses using the limited in-situ investigation data. In this study, a back-analysis approach for the determination of the hydraulic conductivities along a rock cavern is presented. To take the advantages of both the analytical solutions and the numerical methods, this paper proposed a semi-analytical approach for prediction of the water inflow into caverns with the horseshoe section, and the semi-analytical solution is used for the back-analysis of the hydraulic conductivity around a rock cavern based on the in-situ monitoring data. The hydraulic conductivities are obtained by using the EXCEL spreadsheet’s build-in optimization routine SOLVER to minimize the error function. The computed water inflow into the cavern is compared with the in-situ measured data. The results indicate that the derived hydraulic conductivity is acceptable.