桩承式路堤中土拱形态与成拱过程中土拱效应研究

建立了平面应变条件下模拟土拱形成过程的弹塑性有限元模型。研究了桩承式路堤中的土拱形态,分析了影响土拱高度的主要因素和土拱形成过程中桩帽与桩帽间地基土之间的荷载分担特性。研究表明：平面应变条件下土拱的形态为半椭圆,填土内摩擦角和凝聚力的变化对土拱高度的影响较小。土拱高度随桩帽净距的增加先增大后逐渐减小,随路堤高度的增加先线性增加后稳定不变。完整土拱形成时土拱效应发挥程度最大,桩帽间地基土承担的路堤荷载不再向桩帽上转移。

Shape of soil arching and development of its effect in a piled embankment

A two-dimensional elastic-plastic finite element model which can simulate the process of development of soil arching in a piled embankment is established. The shape of soil arching in a piled embankment is simulated. Then, parameter study on height of soil arching is made. Finally, the behavior of embankment load transferring from the surrounding soils to the pile caps is investigated. The results indicate that the shape of soil arching in a piled embankment is semi-elliptic under the condition of plane strain. The influence of the values of internal friction angle and cohesion of embankment fill on the height of soil arching is smaller. The height of soil arching increases firstly with the increase of net spacing between pile caps, and then decreases gradually. Furthermore, it increases?linearly firstly with the increase of the height of embankment, and then remains the same for a higher embankment. The load shared by the subsoil remains unchanged after the entire soil arching appears.