离心模型试验中路堤地基差异沉降控制装置的研制

为了利用离心模型试验研究地基差异沉降在路堤中的传递扩散规律及对路基面不均匀变形的影响机制，研制了一套可以在离心机运转条件下实现路堤地基差异沉降的精确控制装置，该装置由位移控制系统、固定支撑墩及差异沉降控制板等部分组成。通过设在外部的控制器控制步进电机驱动升降机升降带动差异沉降控制板沉降模拟地基的差异沉降，多次控制沉降板沉降可实现地基差异沉降全过程的模拟。采用该装置进行了3组不同高度路堤的离心模型试验，验证了试验装置的可靠性和有效性。试验结果表明：路基面不均匀变形的斜率与地基差异沉降幅值基本呈线性关系；在路基面不均匀变形斜率相同时，地基差异沉降的允许幅值随路堤高度的增加而增大。

Development of Control Device in Centrifugal Model Test for Differential Settlement of Embankment Foundation

A device which can control the differential settlement of embankment foundation under centrifugal loading conditions is developed to investigate the transfer and diffusion of differential settlement as well as its influence on the uneven deformation of subgrade surface.The device consists of settlement control system,fixation and supporting device,and differential settlement control boards.Differential settlement of embankment foundation is simulated through the external controller which controls the stepping motor to drive the elevator and to make the differential settlement control boards work.The whole process of differential settlement can be simulated by repeatedly controlling the settlement boards.The device is verified to be reliable and effective by three groups of centrifugal model tests on embankments of different heights.The results show that the uneven deformation slope of subgrade surface have linear relationship with differential settlement of embankment foundation,and the allowed values of differential settlement of embankment foundation increase with the embankment height when the uneven deformation slope of subgrade surface is the same.