渗流–侵蚀–应力耦合管涌试验装置的研制及初步应用  

DEVELOPMENT OF SEEPAGE-EROSION-STRESS COUPLING PIPING TEST APPARATUS AND ITS PRIMARY APPLICATION

作　　者：罗玉龙[1] 吴强[1] 詹美礼[1] 盛金昌[1] 

机构地区：[1]河海大学水利水电学院,江苏南京210098

出　　处：《岩石力学与工程学报》2013年第10期2108-2114,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51009053);高等学校博士学科点专项科研基金项目(20100094120004)

摘　　要：管涌是涉及孔隙水渗流,可动细颗粒侵蚀、运移,多孔介质变形等众多复杂力学行为的多相、多场耦合现象。为真实模拟管涌发展过程、探究管涌机制,研制渗流–侵蚀–应力耦合管涌试验装置。该装置包括流失细颗粒收集系统、围压系统、轴向压力系统、渗透压力系统及数据采集系统。流失细颗粒收集系统可以实时收集管涌发展过程中流出土体的细颗粒及渗流量;围压及轴向压力系统模拟土体承受的三向应力状态,最高围压可达2.0MPa,最大轴向压力可达30 kN(试样直径101 mm);渗透压力系统模拟土体承受的渗流作用,具有高水头(200 m)与低水头(低于2 m)2种模式;数据采集系统能够实时监测土体沉降、体积及渗流进、出端水头的变化等。无围压、等向受压、三轴受压3组管涌试验表明:应力状态对管涌发展过程影响显著。等向受压状态下管涌临界坡降远高于无围压时的结果,略高于三轴受压状态下的临界坡降。新型管涌试验装置能够真实模拟土体管涌发展过程,实时监测管涌发展过程中土体细观结构、几何、水力、力学特性的演变,将成为深入研究管涌机制的可靠技术工具。Piping is a multiphase and multifield coupling phenomenon involving numerous complicated mechanical behaviors,such as pore water seepage,fine particle erosion and migration,and deformation of porous media. A new seepage-erosion-stress coupling piping test apparatus is developed to simulate the evolution of piping and study the mechanism. The new apparatus consists of a special funnel-shaped drainage system,a confining pressure system,an axial pressure system,a seepage pressure system and a data acquisition system. The funnel-shaped drainage system is specially designed to collect the eroded fine particles and water. The confining and axial pressure systems are used to simulate the triaxial stress state of specimen. The largest confining pressure is up to 2.0 MPa,and the largest axial load is about 30 kN（the diameter of specimen is 101 mm）. The seepage pressure system provides the migration power of fine particles,which can realize a fast switch from high hydraulic head（200 m） to low hydraulic head（〈2 m）. The data acquisition system can monitor the variations of pore pressure and settlement. The three experiments under different stress states indicate that the stress state has a great influence on the evolution of piping. The critical piping hydraulic gradient under isotropic compression is far higher than that under no confining pressure,and is slightly higher than that under triaxial compression. The new apparatus can simulate the evolution of piping,and monitor the evolution of meso-structure,geometric,hydraulic and mechanical characteristics,which will provide a credible tool for studying piping mechanism.

关 键 词：土力学 管涌 渗流-侵蚀-应力耦合 临界坡降 出砂量 

分 类 号：TU41[建筑科学—岩土工程]