基于黏聚力模型的土工格栅筋土界面作用模拟方法

Simulation for interaction between geogrids and soil by cohesive zone model

黏聚力模型被广泛应用于金属构件断裂过程的数值模拟。为深入分析土工格栅筋土界面关系,在格栅纵肋处采用罚函数法,在格栅横肋处采用黏聚力模型,并基于土工格栅横、纵肋条拉拔试验数据确定相关模型参数,进而对土工格栅整体拉拔试验进行了数值模拟。结果表明:黏聚力模型能有效地模拟格栅横肋的被动阻抗作用;格栅横肋前的土体破坏模式与Jewell提出的冲剪破坏模式相吻合;格栅横肋发挥的被动阻抗作用约占整体拉拔力的71%;采用黏聚力模型的筋土界面模拟方法与传统界面模拟方法相比更加准确。

The cohesive zone model is widely used in the fracture numerical simulation of bonded metal members.In order to deeply analyze the interaction between geogrids and soil,the cohesive zone model is adopted at the transverse ribs of geogrids and penalty function method is adopted at the longitudinal ribs to simulate the pullout tests of geogrids.The parameters of model can be obtained from the data of pullout tests on individual ribs.The results show that the cohesive zone model can perfectly simulate the passive resistance of transverse ribs,and the failure mode corresponds to the punching failure mode proposed by Jewell.The passive resistance of the transverse ribs accounts for about 71%of the whole pullout force.The simulated results have well verified the accuracy and feasibility of adopting the cohesive force model at the transverse ribs of the grid.