中文摘要：

针对目前我国土工膜防渗工程设计依然以单向拉伸试验结果为依据,而土工膜在堆石坝面防渗体实际运行中却处于双向拉伸应力状态的问题,采用自主研发的2 种双向拉伸试验装置对堆石坝面防渗土工膜的双向拉伸力学特性进行试验研究.对堆石坝防渗常用的几种土工膜分别进行了不同双向拉伸状态下的力学特性试验,并和单向拉伸试验结果进行对比,得到了双向拉伸状态下土工膜的拉伸强度、延伸率、弹性模量和泊松比等力学参数以及真应力真应变关系曲线.试验结果揭示了高面膜堆石坝防渗土工膜在真实工作状态中的受力变形特性及破坏机理,为面膜防渗体设计计算和受力变形数值分析提供了一定的理论基础和计算依据.

英文摘要：

The geomembrane impervious barrier of hydraulic structure engineering is usually designed on basis of results of uniaxial tensile test. But geomembrane is actually in plain stress state in practical project. The principal stresses are in biaxial stress state. Two self-developed biaxial tensile devices and corresponding test methods were employed to investigate the mechanical property of geomembrane which is used as the surface barrier of high rock-fill dam. Several groups of tests with different biaxial tensile conditions were carried out for several geomembrane usually used in rock-fill dam. Then the experimental results were analyzed in contrast to that of conventional uniaxial tension tests. The mechanical property include tension strength, elongation, elastic modulus, Poisson' s ratio and true stress-strain relationship under different biaxial tension states were obtained. That revealed the stress-deformation properties and failure mechanism of geomembrane in actual working condition for rock-fill dam. The test results can provide some theoretical foundations and basis for the design and numerical analysis of geomembrane surface barrier of rock-fill dam.