深厚覆盖土层中桩的有效桩长

采用线弹塑性荷载传递函数，按极限承载力控制法确定深厚覆盖土层中桩的有效桩长，分析了桩的刚度系数，桩端土持力层弹性模量与桩周土弹性模量之比值，桩侧极限位移，桩顶沉降量，桩径和土的泊桑比等因素对桩有效桩长的影响，其结果表明：除土的泊桑比和桩端土持力层弹性模量与桩周土弹性模量比值对桩有效桩长的影响不明显外，其余因素均有一定或较大的影响，且与弹性理论法分析结论一致，为了将理论分析应用到工程实际中，对各参数在工程桩中的取值进行了分析。

Effective length of foundation pile in the soil layers of deep overlay

According to the control method of the ultimate bearing capacity,effective length of a pile in the soil layers of deep overlay is analyzed and calculated with linear elastic plastic load transfer function. Influential factors of effective length such as coefficient of pile rigidity, elastic modulus ratio of the bottom soil and surrounding soil, side ultimate displacement, pile's diameter and Poisson ratio of soil are thoroughly analyzed. The results show that the factors have certain effects on the effective length except Poisson ratio of soil and elastic modulus ratio of the bottom soil and surrounding soil. These results agree with analytic conclusions of the elastic theory method. In order to apply in practical project, the determination of relevant parameters is discussed.