粘性土地基墩式基础承载力试验研究

Research on bearing capacity test of pier foundation on cohesive soil

通过对大量的现场试验数据和观测资料进行统计分析,论述了墩式基础的受力机理,指出了粘性土地基墩式基础破坏模式不同于砂土地基的压密式渐近破坏。提出了持力层为粘性土时的单墩竖向承载力计算公式,并分别给出了墩端土和墩周土的承载力调整系数。根据对比试验结果,墩底形状为平底时对墩端土承载力的发挥最有利。基础底面尺寸效应对墩式基础的承载力有显著影响,随着墩底直径增大,调整系数呈降幂指数规律衰减。

The mechanism and an empirical formulation of vertical bearing capacity of non-reinforced concrete pier in cohesive soil are proposed based on field load testing data of piers. In the proposed formulation, the adjustment coefficient of both the end bearing and skin friction of the piers are given. The testing results show that a belied pier with flat end would have the largest end bearing capacity comparing with other end shape of belied piers. The results show that the size effect of end of belled pier has a significant influence on the bearing capacity of pier.