桩承式加筋路堤的混合试验模拟方法研究

A Method for Hybrid Test Simulation on Geosynthetic-reinforced Pile-supported Embankment

桩承式加筋路堤的路堤土拱效应、加筋体张拉膜效应与桩土地基承载之间存在耦合作用,模型试验往往将桩土地基简单地采用桩土差异沉降代替,难以评价运营期长期性能的动态演化。为实现对桩承式加筋路堤体系各组件共同工作长期效应的模拟,开发了一套包含物理-数值数据交互系统的阵列式多活动门装置以及一种岩土工程地基混合试验方法。该方法将路堤与加筋垫层采用物理模型进行模拟,将桩土地基采用数值模型替代,以阵列式多活动门装置为硬件平台进行物理模型底面与数值模型顶面的位移与荷载适时交互,从而实现了桩承式加筋路堤体系全组件参与的试验模拟。以某现场试验为案例,开展了桩承式加筋路堤施工期全过程的混合试验模拟,将试验得到的桩土荷载分担、超孔隙水压力、路堤变形与原型实测结果进行了对比。结果表明:混合试验得到的结果与现场试验变化趋势相同,数值较为接近,说明混合试验可以较好地模拟路堤—加筋垫层—桩土地基体系的复杂作用,可以用于桩承式加筋路堤长期工作性能的预测;由于耗时较长的地基土固结过程通过数值模拟计算,实时得到路堤底面的非均匀下沉曲面,相较于现场试验大大缩短了模拟时间,为相关岩土工程问题研究提供了一种全组件、全效应耦合的大比尺试验方法。

There is a coupling effect among the soil arching effect of the embankment,the tensioning effect of the reinforced body and the bearing capacity of the pile-soil foundation,it is difficult to evaluate the dynamic evolution of long-term performance.In order to simulate the long-term effect of the interaction of the components of the pile-supported reinforced embankment system,a set of array multi-movable door device including physical-numerical data interactive system and a hybrid test method for geotechnical engineering foundation are developed.In this method,the physical model is used to simulate the embankment and reinforced cushion,and the numerical model is used to replace the pile-soil foundation,the displacement and load interaction between the bottom of the physical model and the top of the numerical model are carried out on the hardware platform of the array multi-movable door device.Taking a field test for an example,the hybrid test simulation of the whole construction process of pile-supported reinforced embankment is carried out,the test result of pile-soil load sharing,excess pore water pressure and embankment deformation are compared with the prototype test results.The result shows that(1)the hybrid test results have the same tendency with the field test,and the numerical values are close to each other,which show that the mixed test can well simulate the complex action of embankment-reinforced cushion-pile-soil foundation system,it can be used to predict the long-term performance of pile-supported reinforced embankment;(2)because the timeconsuming consolidation process of foundation soil is calculated by numerical simulation,the non-uniform subsidence surface of embankment bottom can be obtained in real time,and a large scale test method isprovided for the study of related geotechnical engineering problems.