等效矩形法计算不规则区域荷载下地基中附加应力

为简化基础底板形状不规则时的地基沉降计算,通过分析荷载区域几何形状对地基中附加应力的影响,提出以等效矩形替代原不规则荷载区域的等效矩形法。分析结果表明,均布荷载作用下,荷载区域总面积相同,且荷载强度相同时,若荷载区域几何形状不同,则在各自的最大沉降计算点下深度约为槡A/2处,地基中附加应力之间的差别最大,同时矩形中心点下该深度处的附加应力系数随着矩形圆形度的增加而增大。利用这一原理,对Newmark感应图法加以改进,提出3D-Newmark感应图法,以确定等效矩形的具体几何尺寸。

EQUIVALENT RECTANGLE METHOD FOR ADDITIONAL STRESS CALCULATION WITH LOAD DISTRIBUTION BEING NOT REGULAR IN SHAPE

When the loaded mats or rafts are not regular in shape,in order to simplify the calculating process of ground settlement,the equivalent rectangle method that the irregular loaded area was substituted by equivalent rectangle is proposed according to analyzing the influence of geometric figure of loaded area on additional stress in foundation.Which shows that if there are uniform loads with different load area but the same load intensity and total area,when the depth is about A/2,the difference of additional stress in foundation at maximum settlement point is the greatest,and the additional stress coefficient at that depth beneath the rectangle center is increased with the circularity degree of rectangle.In terms of this principle,the 3D-Newmark’s influence chart method for ascertaining the detail dimensions of equivalent rectangle is introduced by the improved Newmark influence chart method.