试验温度对复合土工膜结构面摩擦性能及稳定性的影响

Effect of Test Temperature on Tribological Properties and Stability of Composite Geomembrane Structural Surface

复合土工膜界面摩擦特性对工程结构稳定性至关重要。复合土工膜为高分子材料,其性能受温度影响较大,为探明环境温度对复合土工膜防渗结构界面稳定性的影响,采用直接剪切试验测定界面摩擦参数,对试验数据进行综合对比。结果表明:复合土工膜原材料的试验中,随试验温度的增加,力学性能大幅下降,同时变形量增加,原材料随着温度的升高出现明显的软化现象;进行界面摩擦试验时,随试验温度的升高摩擦角降低明显,温度由20℃增加至60℃,界面摩擦角降低约3°~5°;布面与砂砾石界面摩擦性能优越,安全系数最高,硬性结构与塑膜面、布面摩擦角较小,安全系数均小于1.0,在温度为60℃时,安全系数仅为0.65。在进行防渗结构稳定性分析时,需考虑温度对界面摩擦性能的影响。

The interfacial friction characteristics of composite geomembranes are very important for the stability of engineering structures.The composite geomemmembrane is a polymer material, and its performance is greatly affected by temperature.In order to explore the influence of environmental temperature on the interface stability of the composite geomemmembrane impermeable structure, the interface friction parameters were measured by direct shear test, and the test data were comprehensively compared.The results show that the mechanical properties of composite geomembrane materials decrease greatly with the increase of the test temperature, while the deformation increases, and the material appears obvious softening phenomenon with the increase of temperature.In the interfacial friction test, the friction Angle decreases obviously with the increase of the test temperature.The friction Angle decreases about 3°~5° when the temperature increases from 20 ℃ to 60 ℃.The friction performance of cloth surface and sand gravel interface is superior, and the safety coefficient is the highest.The friction Angle between rigid structure and plastic film surface and cloth surface is small, and the safety coefficient is less than 1.0.When the temperature is 60 ℃,the safety coefficient is only 0.65.The influence of temperature on interface friction performance should be considered in the stability analysis of impermeable structure.