【摘要】 为探明竖向荷载作用下群桩的夹持作用特性,运用数值模拟对群桩夹持作用的产生机理、作用范围等进行研究。通过对应力应变关系、压缩沉降曲线的分析,提出了夹持作用范围特征值a、b。结果表明:群桩的夹持作用的产生机理主要是群桩对桩间土"裹挟下沉"及"侧限受压"作用;在夹持作用下,群桩的桩间土可以大致分为3个特征区间,即浅层受拉区、中部传力区、底部承压区;在极限荷载下,随着桩长增加特征值a趋于一个稳定值(d=0时这个值取7),而特征值b则近似呈直线增长,且L-b保持定值12;随着桩径增大a值出现峰值,b值则保持稳定。更多还原

【Abstract】 In order to find out the clamping characteristics of pile group under vertical loads,numerical simulation was applied to study the mechanism and scope of the clamping action.Through the analysis of the stress-strain relationship and the compression-settlement curve,the characteristic values a and b of the clamping action range were proposed.The results show that the occurrence of clamping is mainly due to the"co-sinking"and"lateral compression"effects of pile group on the inter-pile soil;under the action of clamping,the soil among the pile group can be roughly divided into three characteristic sections,namely "shallow tension zone","central force zone"and "bottom pressure zone";as the pile length increases,the characteristic value a tends to a steady value under the ultimate load(this value is taken as 7 when d=0),while the characteristic b approximates to grow linearly and L-b maintains a constant value of 12;as the diameter of pile increases,the value of aappears to reach its peak,while the value of b remains stable.更多还原