中文摘要：

基于桩-土相互作用的机理,利用剪切位移法及叠加原理推求了膨胀土地基中考虑膨胀土膨胀时的单桩荷载传递的解析解,并编制了相应的程序进行各影响参数的分析。分析结果表明：桩长增加,桩身抬升位移减小,桩身拉力的增加;埋入膨胀影响深度以下较深的小直径桩（d〈0.044L）能有效地降低膨胀土中桩顶位移,而大于该直径,桩径的增加对桩顶位移减小量用处不大;桩顶荷载的增加,桩身的抬升位移及拉力逐渐减小,阻止桩向上运动所需的桩顶荷载约为未受荷载的桩中最大拉力的2.5倍。研究结果为膨胀土中桩基的合理设计提供了理论依据。

英文摘要：

The derivation of analytic solution to load-transfer for single pile in expansive soil under its swelling was carried out by the shear-deformation method and superposition principle.The corresponding grogram was then compiled to analyze the various factors that affect the pile behavior in expansive soils.The analyzing result show as follows： with the increase of the pile length,upward pile movement could decrease greatly,but meanwhile,tensile force of pile shaft increase as well;the increases of small piles diameter（d0.044 L） can effectively reduce the upward pile movements in expansive soils while those piles with the diameter over 0.044 L contribute little to reducing the upward pile movement;increasing the loads on pile-top can decrease the upward pile movements and tensile forces;the ratio between the load on pile-top that prevents upward pile movement and the maximum axial force of unloaded pile equals 2.5.The study provides theoretical bases for reasonable pile designing in expansive soils