桩承式路堤离心模型试验过程的地基变形分析

Deformation of centrifugal modelling process of piled embankments

桩承式路堤离心模型地基变形与试验过程紧密相关,通过激光测距法和图像分析法分别研究了各试验阶段复合地基沉降及断面变形的特点及机理。结果表明:1g下制模并使用提高离心加速度的方法模拟路堤堆载无法排除填筑阶段复合地基自身形变,因此高估了路堤填筑阶段的地基沉降量,并使得最终预测沉降预测偏大。在离心减速阶段及放置阶段,地基均有回弹,使用拆模后的断面变形测试数据将低估路中位置的沉降量,并高估坡脚水平位移及坡外隆起。本研究丰富了对桩承式路堤离心模型试验过程变形机理的认识。

The deformation of centrifuge modelling of piled embankments is closely related to the test process.The characteristics and mechanism of settlement and sectional deformation of composite foundation at each testing stage are investigated by the laser ranging method and the image analysis method.The results show that it is impossible to eliminate the deformation of the composite foundation itself during the filling stage by preparing the model under 1 g and adopting the method of increasing the centrifugal acceleration to simulate the embankment surcharge.Therefore,the settlements of the foundation during the filling stage and the final settlement are both overestimated in the tests.The foundation rebound is shown at the centrifugal deceleration stage and placement stage under 1 g.As a result,the settlement near the centerline of the road will be underestimated,and the horizontal displacement at the slope toe and the uplift outside the slope will be overestimated based on the measured deformation after the centrifugal tests.This study may enrich the understanding of centrifugal deformation process tests on piled embankments.