基于DPDM技术的上覆硬土层软土地基变形场分析

Analysis of Deformation Field of Soft Subsoil with Upper Crust Based on DPDM Technique

通过室内双层地基模型试验,对双层地基上部硬土层在不同强度和厚度条件下的承载性能进行了研究,并拍摄数码图像分析了双层地基的变形场.利用无标点数字图像量测技术(DPDM)对双层地基变形的数码图像进行变形场分析,通过网格图的变形分析,土体的初始变形出现在下部软土层中,随着荷载的增大,网格的变形区域逐渐向上部硬土层及软土层下部发展,同时向水平方向扩展;双层地基破坏模式为冲剪破坏.研究内容为双层地基承载力计算和提高地基处理效能提供了依据.

This article makes a study of the bearing performance of double-layered soil with different strengths and thicknesses of the upper crust through indoor model test. And the deformation field of double-layered soil is analyzed by observing its digital images made during the test and using the digital photogrammetry for deformation measurement（DPDM） technique. The results of grid-diagram analysis show the initial deformation occurred in the lower soft soil, and the deformation zone in grid-diagram stretches gradually upwards to crust, downwards to the bottom and horizontally with the increase of load. The failure mode of double-layered soil is punching failure. The study results provide the referential basis for calculation of bearing capacity of doublelayered soil and raise of effectiveness of foundation treatment.