Data on Load-Spread Angles for Circular Footing on Two-Layered Soil System around cement corridors, Yerraguntla Town, Proddatur, A.P., South India

The paper presents an analysis of a uniformly loaded circular footing on two-layered soil system consisting of stiff layer overlying soft one. The variation of normal stresses with distance at the interface between the two layers is obtained using PLAXIS software for different modular (E₁/E₂) and relative thickness (h/a) ratios where E₁and E₂ are deformation moduli of the stiff upper and lower layers respectively, h –the thickness of the upper layer and a -the radius of the footing. A Bell-curve is fitted to this variation of normal stresses with distance and integrated to estimate radial extents for different percentages of load transferred at the interface. The load spread angle defined as the ratio of extent of radial distance over which a prescribed percentage of loads is transferred to the thickness of the upper layer is obtained for different modular and relative thickness ratios and for different percentages of load. Load spread angle increases with increase in modular ratio, E₁/E₂ and with h/a. The load spread angle increases marginally for thickness ratio, h/a, greater than 2.0.<br>

本文针对由上覆硬土层与下卧软土层构成的双层土体体系，开展均布荷载作用下圆形基础的受力分析。针对不同模量比（E₁/E₂）与相对厚度比（h/a）工况，借助PLAXIS软件求解得到两层土层界面处法向应力随距离的变化规律；其中E₁、E₂分别为上覆硬土层与下卧软土层的变形模量，h为上层土层厚度，a为基础半径。将钟形曲线拟合至上述法向应力随距离的变化关系，并通过积分计算，得到界面处不同荷载传递百分比对应的径向影响范围。针对不同模量比、相对厚度比以及荷载传递百分比工况，计算得到荷载扩散角；该角度定义为：指定荷载传递百分比对应的径向距离范围与上层土层厚度的比值。荷载扩散角随模量比E₁/E₂与相对厚度比h/a的增大而增大。当相对厚度比h/a大于2.0时，荷载扩散角仅小幅增长。