基础长宽比对压缩层深度的影响

目的 合理确定压缩层深度，提高地基沉降计算精度．方法 通过对现有实测资料的分析，对应力比法、变形比法、经验公式、何颐华法等4种方法在计算精度上进行了评价．基于土的连结强度。研究基础长宽比对基底附加应力和压缩层深度的影响．结果 附加应力随深度发展逐渐减小，长宽比小的附加应力减小的速率快；基础长宽比不同。压缩层计算深度不同．在定义单向和双向筏板的基础上，提出根据基础长宽比不同，应采用不同的方法计算压缩层深度．结论 当基础长宽相近时，采用何颐华法计算压缩层厚度；而当基础长宽比较大时，按经验公式计算．算例表明，根据基础长宽比，按照不同计算公式计算压缩层深度进而计算基础沉降，其结果有很大的不同。

Effect of Foundation Length-width Ratio on Compressed Layer Depth

In order to calculate the depth of compressed layer reasonably and increase the precision of settlement calculation via practical measuring data in existence,the calculating precision of stress-ratio method,deformation-ratio method and etc.were evaluated precisely.Based on the connecting strength of soil,the effects of foundation length-width ratio on base additional stress and depth of compressed layer were discussed.The base additional stress decreased while deepening to the base.The base additional stress of the foundation with small length-width ratio decreased faster.The foundation with different length-width ratio had different depth of compressed layer.Based on defining the one-way and two-way raft,advices were put forward to adopt different methods to calculate the compressed layer depth according to the differences of foundation length-width ratio.In conclusion,when the foundation's length was close to the width,the depth of compressed layer was calculated by He Yi-hua method;otherwise by experienced method.A calculating example showed that the results of the calculating settlement were quite different when adopting different methods to calculate compressed layer depth and then calculating the foundation settlement.