半刚性基层振动压实时的下承层动力响应分析

为判断半刚性基层振动压实能否造成下承层的早期破坏,对半刚性基层在移动—振动压实荷栽作用下的下承层动态应力响应进行分析.将振动压路机对压实层施加的作用力简化成周期性变化的矩形均布压力,采用移动—振动荷载模型模拟振动压路机在振动压实过程中对压实层施加的作用,并对该振动压实荷载利用APDL语言编制相应的分析程序,实现了在有限元模型上的施加与求解.采用三维有限元瞬态动力分析方法以及ANSYS有限元程序,计算、分析半刚性基层在振动压实作用下的下承层的动态应力响应,建立了一种振动压实荷载作用下的路面结构层动态应力响应分析方法.算例显示,在下基层施工后7d,振动压实上基层时下承层动态拉应力峰值接近下承层的极限抗拉强度,可能会出现产生早期破坏,从而表明在半刚性基层振动压实时进行施工荷载与施工时机控制是必要的. 振动荷载模型模拟振动压路机在振动压实过程中对压实层施加的作用,并对该振动压实荷载利用APDL语言编制相应的分析程序,实现了在有限元模型上的施加与求解.采用三维有限元瞬态动力分析方法以及ANSYS有限元程序,计算、分析半刚性基层在振动压实作用下的下承层的动态应力响应,建立了一种振动压实荷载作用下的路面结构层动态应力响应分 方法.算例显示,在下基层施工后7d,振动压实上基层时下承层动态拉应力峰值接近下承层的极限抗拉强度,可能会出现产生早期破坏,从而表明在半刚性基层振动压实时进行施工荷载与施工时机控制是必要的. 振动荷载模型模拟振动压路机在振动压实过程中对压实层施加的作用,并对该振动压实荷载利用APDL语言编制相应的分析程序,实现了在有限元模型上的

Analysis of dynamic stress response of lower course by moving-vibrating compaction on semi-rigid base

The dynamic st ress response o f the low er course by moving-vibrat ing compact ion o n semi-rig id base w as analyzed to judg e w hether it caused ear ly w reckage to the low er course. T he pressure of vibrat ing road ro ller on the compacted course w as predig ested to cy clical and rectang le uniform pressure. A movingvibrating load model w as used to simulate the load of v ibrat ing r oad roller during compact ing course, and the load w as applied and so lved w ith APDL based on fini-element model. 3D f ini-element tr ansient dynamic method and ANSYS fini-element pro gram w ere used to calculate and analyze the dynamic st resses of the low er course while vibrat ing compact ion on semi-rigid base. So a metho d of analy zing dynamic st resses o f pav ement st ructure under vibr at ing compact ion w as buil t . The calculation ex ample show s that the peak value of dynamic tensile str ess on low er course by vibrat ing compact io n approaches the tensile str ength of this course w hich may cause early w reckage to the low er co urse in 7d, meanw hile it al so shows the necessity o f cont rol of const ruct ion load and const ruct ion t ime dur ing vibrating compacting on semi-r ig id base