中文摘要：

为研究充填介质在赋存条件下的渗透、力学特性及其破坏机制,改进研制了大比尺三轴应力-渗流耦合试验系统,开发了三维应力-渗流耦合压力室,进行了完善的密封和加载系统设计。系统具备自动化轴压加载、围压渗压加载、涌水涌砂量采集和多元信息并行监测等功能,该套装置可针对大尺寸、不同规格岩溶管道和裂隙还原其在原始地应力状态下进行渗透性及相关力学试验研究。围压、渗压值可分别加到2 MPa和5 MPa,轴向荷载最大可加到300 kN。光纤技术、电阻元件柔性防水技术和自动化数据采集分析系统的应用,实现了水环境下试件内部渗压、应变的精确采集和分析。在试验系统的基础上,开展了赋存环境下充填介质渗透特性试验研究,分析了充填介质类型、渗流路径、管道断面形状及应力条件4种因素对渗透特性的影响及充填介质的响应特征,揭示了充填体稳定性和渗透性的变化规律。该装置解决了小水力梯度及赋存条件下的充填介质渗透特性和力学性质试验研究技术难题,具有重要意义。

英文摘要：

To investigate the permeability characteristics of filling media and its mechanical properties and failure mechanisms under high water pressure conditions, a large-scale testing system was developed for the measurement of coupled seepage and triaxial stress. We proposed a pressure chamber especially for coupling three-dimensional（3D） seepage-stress, and designed a perfect sealing and loading system. This system has multiple functions including automatically applying triaxial stress, surrounding rock pressure and osmotic pressure, gushing water and sand acquisition and monitoring parallel multivariate information. It can be used to perform the tests of permeability and correlative mechanics measurement for large-scale and different patterns karst conduit and karst fissure under the initial confining pressure. The maximum applied lateral pressure and permeability pressure are up to 2 MPa and 5 MPa, respectively. The maximum axial loading capacity is 300 kN. The precise acquisition and analysis of seepage pressure, strain and displacement in the water environment can be achieved by the fibre technology, flexible waterproof technology of resistor elements and automatic data acquisition system. The permeability tests were conducted on filling medium under the condition of occurrence, and seepage characteristics of different kinds of filling medium were systematically analysed. The seepage failure model of filling medium was further revealed. Therefore, the developed system provides a new testing method for hydropower and tunnelling engineering.