考虑冲刷影响的筒型基础竖向极限承载力研究

大直径宽浅式筒型基础,阻水宽度大,在位工作期间受波浪海流作用,其周围土体易被冲刷。为研究单侧地基土体受冲刷后筒型基础的竖向极限承载力变化,通过引进冲刷率的概念,采用有限元方法研究了不同冲刷率下筒型基础的竖向极限承载力;并基于Meyerhof理论建立了计算不同冲刷率下筒型基础竖向极限承载力的极限平衡方法。研究结果表明,随着冲刷率增大,筒型基础的极限承载力出现不同程度的下降,当冲刷率为0.8时,即筒型基础单侧土体冲刷深度达6.4 m时,筒型基础的竖向极限承载力折减率为3.28%。建立的极限平衡算法可准确计算冲刷条件下筒型基础的竖向极限承载力。

Study on vertical ultimate bearing capacity of bucket foundation considering scour effect

The large-diameter wide-shallow bucket foundation has a large water-blocking width, and is subjected to wave and current during the working period, and the surrounding soil can be easily scoured. In order to study the vertical ultimate bearing capacity change of the unilateral foundation soil after scouring, the vertical ultimate bearing capacity of the bucket foundation under different scouring ratios was studied by introducing the concept of scouring ratio and based on the finite element method. Based on the theory of Meyerhof, the limit equilibrium method for calculating the vertical ultimate bearing capacity of the bucket foundation under different scouring ratios is proposed. The calculated results can be consistent with the finite element results, and the errors are controlled within 6%. The results also show that as the scouring ratio increases, the ultimate bearing capacity of the bucket foundation decreases to a different extent. When the scouring ratio is 0. 8, that is, the scoured depth of the single-sided soil on the bucket foundation is 6. 4 m, the vertical ultimate bearing capacity of the bucket foundation reduction rate is 3. 28%.