黏土地基中的基础浮力模型试验

Model experiment on foundation buoyancy in clay

针对位于黏土地基中的建筑基础是否存在浮力折减的问题和争议,本文提出直观易懂的地下水浮力模型试验方法,不需借助任何测试仪器,直接将4个不同重量的基础模型埋置于黏土地基中,观察其上浮情况,并找出浮起的最重基础模型和不浮起的最轻基础模型以确定折减系数的范围,进而通过严格的受力分析计算得出确切的地下水浮力折减系数值。通过3组不同埋深的模型试验,得出黏土地基中的水浮力存在折减,且由试验现象初步估算出的综合折减系数在0.41～0.58之间,经严格受力分析计算得到浮力折减系数为0.73。

With regard to the problem whether there exists buoyancy reduction in building basics in clay foundation,this paper introduces a straightforward model experiment of groundwater buoyancy.The model test is as follows.Without any instruments,four foundation models of different weight are buried in clay foundation and observe their floating situation.Then find out the heaviest foundation model among the float and the lightest one which do not float.In light of this fact,the scope of reduction coefficient can be defined and the accurate reduction coefficient of buoyancy can be got by analyzing and computing the force scrupulously.By Comparing with three model experiments of different burying depth,the author reaches a conclusion that there does exist buoyancy reduction in clay foundation and the synthetical reduction coefficient is from 0.41 to 0.58 according to initial estimation.Moreover,the reduction coefficient of buoyancy is computed to be 0.73.