土工离心模型试验中路堤分层填筑装置的研制  

Development of a test apparatus for staged construction of embankment in geotechnical centrifuge model tests

作　　者：刘宏扬 罗强[1,2] 王威龙 李品锋 马宏飞 张东卿[3] LIU Hong-yang;LUO Qiang;WANG Wei-long;LI Pin-feng;MA Hong-fei;ZHANG Dong-qing(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;MOE Key Laboratory of High-speed Railway Engineering,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.Ltd,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]高速铁路线路工程教育部重点实验室,四川成都610031 [3]中铁二院工程集团有限责任公司,四川成都610031

出　　处：《浙江大学学报（工学版）》2022年第8期1504-1513,共10页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51878560);四川省科技计划资助项目(2021YJ0001)。

摘　　要：为了完善土工离心模型试验中的路堤填筑模拟技术,研制了一套在离心机运转条件下可编程控制的路堤分层填筑装置,其由箱式储砂结构、泄砂推拉机构、步进电机控制系统和摄像系统组成.采用步进电机-行星减速器-滚珠丝杠的组合方案实现大扭矩、高精度动力输出,使低摩阻、小变形的泄砂层与上部储砂结构前后错动,分隔于储砂结构内的高密度锆砂经承力底板上不等径、不等距泄砂孔定量下泄;通过在泄砂孔边缘加装折线形导流板,显著减弱离心场中Coriolis效应对下泄砂粒运动轨迹的影响,降落至地基面预设区的砂粒分层堆积为形状规整的路堤.试验表明,研制的填筑装置在60g离心加速度下,能模拟最小分层厚度20 mm的路堤填筑过程,模型横断面与设计面积相对误差为0.50%~9.50%,实现了模型与原型路堤在几何、密度和强度等方面的相似,具有系统可靠、结构紧凑、功能完整等技术特点.A set of programmable staged embankment construction device was developed in order to improve the simulation technology for embankment construction in geotechnical centrifuge modeling.It is functional during centrifuge operation,and consists of a box-like sand container,sand falling push-pull element,a stepper motor controller and a camera system.A combination of stepper motor,planetary gearbox,and ball screw achieves high torque and resolution of dynamic output,so that the sand falling layer,featuring low friction and small deformation,can move back and forth relative to the upper sand container.Then,the high-density zircon sand in the box-like sand container can pass through sand falling holes with different diameters and spacing,which are located on the basal bearing plate.The influence of Coriolis effect on the movement trajectory of the sand particles was significantly reduced by installing segmented deflectors on the edge of sand falling holes.The zircon sands fell along the deflectors to the surface of foundation,and then formed a regular-shaped embankment.The trial experiment showed that the developed apparatus can better simulate the staged construction process of embankment with minimum layer thickness of 20 mm at a centrifugal acceleration of 60g.The relative error of cross section between the simulated embankment and the target embankment was 0.50%~9.50%.This device achieved the similarity between the model embankment and the prototype in terms of geometry,density and strength.The device is characterized by high system reliability,compacted structure and full functionality.

关 键 词：土工离心模型试验 路堤 分层填筑模拟 泄砂装置 Coriolis效应 

分 类 号：TU43[建筑科学—岩土工程]