侧移土体被动桩成拱效应及主动侧土压力计算

采用三维数值模型模拟土体水平位移条件下被动桩的成拱效应。分析结果表明,被动桩的成拱效应和桩间距关系最为密切,桩间距较小时,侧移土体在桩周附近呈现出明显的土拱效应,应力等值线密集,相互连通成一整体,并向两端突出,桩间距增大时土拱效应减弱;随着作用于土体侧向荷载的增大,土拱效应增强,桩周应力区增大。在数值分析的基础上,以T.Itos土压力为依据,考虑土体的实际分层,探讨了考虑土拱效应的土压力计算方法,给出了被动桩计算模式,最后将简化方法与数值分析的桩侧土压力进行了对比。

Soil Arching Effect in Passive Piles and Time Effect Analysis

Three dimension numerical model was set up to discuss the soil arching effect of passive piles due to soil lateral displacement.The analysis results show that the pile space has obvious influence on soil arching effect.When pile space is relatively small,the lateral displacement soil takes on obvious soil arching effect around piles.The stress contour line is mutually conjunctive and extrude toward two sides.When pile space become larger,the soil arching effect become unconspicuous.With the increasement of lateral load the soil arching effect will enhance and the stress block around piles will become larger.Based on the numerical analysis,a calculational method of soil pressure was put forward considering actual soil layer,according to Ito soil pressure theory.Finally the soil pressure of pile shaft from the calculation method and numerical analysis were compared.