| 摘要: |
| 利用改装的土石料大型剪切仪对土工膜-砂砾石界面开展循环剪切试验,模拟土工膜界面的动力剪切特性,得到不同竖向压力下滞回曲线、主干线和阻尼比变化曲线,建立相应的剪切劲度和等效阻尼比数学模型。在此基础上对循环剪切试验开展有限元数值模拟,其计算结果与试验值总体吻合较好,合理反映了土工膜界面动力剪切过程的非线性和滞后性。最后,将所建土工膜界面本构模型应用于土工膜防渗土石坝的抗震分析中,计算得到的坝面土工膜的动位移、加速度、动主拉应变和动主拉应力符合一般规律,表明所建土工膜界面动力本构模型用于土工膜防渗土石坝抗震分析是正确可行的。 |
| 关键词: 土工膜 循环剪切试验 剪切劲度 等效阻尼比 土石坝 抗震分析 |
| DOI： |
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| 基金项目:国家自然科学基金(51679073,51979089),水利部堤防安全与病害防治工程技术研究中心开放基金(2018004) |
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| Numerical simulation of dynamic shear characteristics of geomembrane interface and its application |
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CEN Weijun
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College of Water Conservancy and Hydropower Engineering,Hohai University
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| Abstract: |
| A series of cyclic shear tests were carried out on geomembrane-gravel interface using a modified large-scale soil-stone shear instrument. Dynamic shear characteristics of geomembrane interface were simulated. Nonlinear hysteretic curves, backbone curves and damping ratio variation curves under different vertical pressures were obtained, and corresponding mathematical models of shear stiffness and equivalent damping ratio were established. Further, the finite element numerical simulation of cyclic shear test was performed, and the results are in good agreement with the test data, which reasonably reflects the nonlinearity and hysteresis of dynamic shear characteristics. Finally, the established geomembrane interface model was applied to the dynamic response calculation of geomembrane faced earth-rock dam. The calculated dynamic displacement, acceleration, dynamic principal tensile strain and dynamic principal tensile stress of geomembrane on the dam surface conform to the general rules, which indicates that the established interface model is correct and feasible for seismic analysis of geomembrane faced earth-rock dam. |
| Key words: Geomembrane Cyclic shear test Shear stiffness Equivalent damping ratio Geomembrane faced earth-rock dam Seismic analysis |
