强度和变形双控条件下基础尺寸的设计及优化

新的地基设计理论提出了依据基底荷载与沉降的p–s曲线,按照强度和变形双控的原则进行基础设计,但不同的基础尺寸其对应的p–s曲线也是不同的,如何依据基底荷载与沉降的p–s曲线确定基础的合理尺寸,以满足地基强度和变形双控的原则,这是一个很具体和有意义的工作。本文基于原位压板试验的p–s曲线反算出土体参数,然后采用切线模量法计算出不同基础宽度的p–s曲线,通过沉降要求和地基强度安全系数要求得到不同尺寸下基础对应的地基承载力,然后根据基底压力确定满足强度和变形要求的最小基础尺寸,并通过案例将该方法与现行规范方法进行比较,说明该方法的合理性。

Design and optimization of foundation sizes under dual control conditions of strength and deformation

The new foundation design theory proposes a method for foundation design based on the p-s curves of base load and settlement with the principle of dual control conditions of strength and deformation. However, the corresponding p-s curves of different foundation sizes are also different. How to determine the reasonable sizes of the foundation according to the p-s curves of base load and settlement to meet the principle of dual control conditions of foundation strength and deformation is a very specific and meaningful work. The soil parameters are calculated based on the p-s curves of the in-situ plate loading tests. Then, the p-s curves of different foundation widths are calculated by the tangent modulus method, and the bearing capacities corresponding to different foundation sizes are obtained by the requirements of settlement and safety factor of foundation strength. Finally, combined with the foundation pressure to determine the minimum foundation size that meets the strength and deformation requirements, the proposed method is compared with the current codes of China through cases, which shows the rationality of this new method.