单桩荷载传递法修正计算分析

Analysis of Single Pile's Load Transfer Improvement Method

基于层状地基采用双曲线模型为荷载传递函数,提出了用Mindlin解和桩土共同作用的联合方法对荷载传递法的进行修正,并计算分析了单桩承载特性。将Lee的方法与双曲线荷载传递函数相结合使得Lee方法中考虑土体横向连续性的优点得以发挥。将横向连续性与竖向连续性修正相结合得到修正荷载传递法,用编制的计算机程序进行了工程实例的计算,结果表明,计算结果与实测值较为接近,其土层的平均SPT值较小,土体较容易产生变形,当试验荷载较高时,可能造成桩周土与桩身之间的滑移。修正荷载传递法与未修正和仅进行竖向修正的荷载传递法相比具有一定的精确性,能更好地反映单桩承载特性,且适用于群桩的分析计算。

Based on the layered foundation and the hyperbolic model, using Mindlin＇ s equation and pile-soil interaction principle, a load-transfer modified method is presented. With the advantage of Lee method and hyperbolic function, the character of soil horizontal continuity can be applied. With the combination of horizontal continuity and vertical continuity, the modified load transfer method is presented.The result of calculation with computer program is close to measured data.The SPT of soil layers are small, and the deformation may takes place easily. When the load is high, there will be slippage between pile and soil around pile. This modified method can overcome restrictions of the original single pile＇ s load-transfer method. The comparison of presented modified method, no-modified method and vertical modified method shows that the presented method has advantage than others, it can reflect the character of single pile loading, and can be used for pile group analysis.