经编涤纶土工格栅与堆石料相互作用离散元模拟研究

DEM analysis of the interactions between warp knitted polyester geogrid and rockfill

摘要

为探明经编涤纶土工格栅与堆石料的相互作用性能及其内在机制，提高经编涤纶土工格栅的工程应用水平，采用离散元方法对经编涤纶土工格栅与堆石料的拉拔试验、直剪界面试验及碾压试验进行了模拟。为使经编涤纶土工格栅在模拟中得到更为真实的还原，提出了一种新的离散元建模方法，能够结合其实际结构特点实现精细化建模，格栅拉伸试验模拟结果对比表明该方法模拟效果良好。分别从宏细观角度对模拟试验结果进行了分析。分析结果显示：直剪界面试验中，界面系数随竖向应力的增加而增加且均大于0.7;碾压过程中，土工格栅会出现不均匀变形且局部位置会出现断裂损伤，导致格栅层的抗拉强度和刚度降低。这些宏细观现象均表明堆石料与经编涤纶土工格栅间咬合即使在低应力水平下也较好。然而，在碾压过程中经编涤纶土工格栅会发生较为严重的施工损伤，不利于在堆石料中应用。

Abstract

To investigate the interaction properties between the warp knitted polyester geogrid rockfill improve application of warp knitted polyester geogrid, pull-out, direct interface roller compaction tests of geogrid reinforced rockfill were simulated using discrete element method(DEM). To achieve more realistic simulation of warp knitted polyester geogrids, new discrete element modeling method proposed, which can combine actual structural characteristics achieve fine modeling. The comparison of simulation result grid tensile test showed this method has good simulation effect. The simulation test result were analyzed from both macro micro perspectives. The analysis result showed in direct shear interface test, interface coefficient increased with increase of vertical stress all greater than 0.7. During roller compaction process, warp knitted polyester geogrid suffered uneven deformation locally fracture damage, which led to reduction of tensile strength stiffness. These macro-microscopic phenomena showed interlocking between rockfill geogrid well even at low stress levels. However, severe installation damage of warp knitted polyester geogrid during roller compaction process detrimental for application in rockfill.

关键词

经编涤纶土工格栅 / 堆石料 / 离散元方法 / 拉拔试验 / 直剪界面试验 / 碾压试验

Key words

warp knitted polyester geogrid / rockfill / discrete element method / pull-out test / direct interface test / roller compaction

Author summay

郑泽东(1998—), 男, 硕士研究生, 主要从事土工合成材料加筋土技术研究。E-mail: [e-mail]

基金资助

雅砻江两河口水电站土工格栅抗震措施效果评价项目(000023-22XB0154)