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对于桩承式路堤作用效应的研究目前主要侧重于对静荷载作用下桩土应力比和土拱效应等,较少考虑动荷载的影响,而车辆运行产生的动应力会对路堤中的土拱产生一定的影响,进而影响桩承式路堤的整体性能。为了分析静、动荷载作用下桩承式加筋路堤的性能变化,采用可视化模型试验和颗粒流数值模拟相结合的方法,对桩承式路堤在静载和动载下的应力传递和变形性状进行研究,分析动载作用下填土高度、桩帽、桩距、加筋形式、荷载频率的影响。试验结果表明,在动载下无筋路堤的桩顶的应力减小,而桩间的应力和位移增大,并且变化的幅度均比加筋路堤大,加筋材料的设置有利于减小动载的影响效应,但不同加筋形式下桩承式路堤的工作性状有所不同,受动载影响程度的大小主要与土拱效应的强弱有关。设置双层加筋时,因加筋材料与周围砂土形成半刚性平台,土拱效应减弱,故受动载影响的程度最小,单层加筋时,格栅设于桩顶上方10 cm比格栅置于桩顶受动载影响的程度明显减小,颗粒流的模拟结果验证了以上结果,并且进一步得出随荷载频率的增加、填土高度与桩净距的减小,动载的影响效应增大的结论。
At present, the research on the effect of pile-supported embankment mainly focuses on the stress ratio of soil and piles and the effect of soil arching under static load, and less considers the influence of dynamic load. However, the dynamic stress generated by vehicle operation will influence the soil arching Have a certain impact, thereby affecting the overall performance of piled embankment. In order to analyze the change of the performance of pile-supported reinforced embankment under dynamic and static loading, the visual model test and particle flow numerical simulation are used to analyze the stress transfer and deformation of pile-supported embankment under static and dynamic loads The effects of filling height, pile cap, pile spacing, reinforced form and load frequency under dynamic loading were analyzed. The experimental results show that the stress at the top of the pile without reinforcement embankment decreases and the stress and displacement between the piles increase, and the variation extent is larger than that of the reinforced embankment. The placement of the reinforced material is helpful to reduce the stress However, the working behavior of pile-supported embankments is different under different types of reinforcement. The degree of influence by dynamic loading is mainly related to the strength of soil arching. When double stiffener is set, the effect of soil arching is weakened due to the semi-rigid platform formed by the stiffened material and the surrounding sand. Therefore, the effect of dynamic loading is minimal. When the single stiffened stiffener is installed, the grille is located at 10 cm above the top of the pile The effect of the grid on the top of the pile is obviously reduced. The simulation results of the particle flow validate the above results, and the results show that with the increase of the load frequency, the filling height and the net spacing of the pile decrease, The effect of increasing the conclusion.