为了模拟土工膜在实际应用中的复杂受力情况，采用“十字形”试样对PE土工膜进行双向拉伸试验研究，探索土工膜在双向拉伸与单向拉伸条件下力学性质的差别，分别对PE土工膜在双向拉伸试验条件下的纵、横向断裂强度和断裂伸长率进行测试，并与单向拉伸试验的相应数据对比。得出以下结论： 1）PE土工膜在双向同时拉伸试验条件下，纵、横向断裂强度分别下降21.53%和60.32%，断裂伸长率分别下降63.07%和64.17%； 2）在一端夹持一端拉伸的试验条件下，纵、横向断裂强度分别下降5.84%和57.14%，断裂伸长率分别下降68.06%和68.47%。

Biaxial tensioning test is made on crossshaped sample of PE geomembrane. The difference between the mechanical performance of PE geomembrane under biaxial tensioning and that under uniaxial tensioning is discussed. The breaking strength and breaking stretching ratio of PE geomembrane in longitudinal direction and transverse direction under biaxial tensioning are measured. The testing data of PE geomembrane under biaxial tensioning are compared with those under uniaxial tensioning. Conclusions drawn are as follows: 1) Under biaxial tensioning, the longitudinal breaking strength and the traverse breaking strength reduce by 21.53% and 60.32% respectively, and the longitudinal breaking stretching ratio and the traverse breaking stretching ratio reduce by 63.07% and 64.17% respectively. 2) Under uniaxial tensioning, the longitudinal breaking strength and the traverse breaking strength reduce by 5.84% and 57.14% respectively, and the longitudinal breaking stretching ratio and the traverse breaking stretching ratio reduce by 68.06% and 68.47% respectively. 