通过几组离心模型试验及成果分析，研究了桩基在水平、弯矩组合荷载作用下的承载机制和承载力屈服包络线特性。结果表明：桩基在水平、弯矩组合荷载作用下承载力屈服包络线形状近似为椭圆形，其承载力屈服包络线方程可用椭圆方程来近似表示；水平、弯矩组合荷载作用下桩基承载力屈服包络线方程为检验桩基在水平、弯矩组合荷载作用下桩基的安全性提供了依据；在桩基设计过程中必须要考虑水平荷载和弯矩荷载之间的相互影响作用。

The load-bearing mechanism and failure envelope behavior of pile foundation under combined horizontal load and moment load were investigated through centrifugal model tests. Analysis on the results revealed that the failure envelope shape of pile foundation under horizontal load and moment load is an ellipse approximately, and the failure envelope equation can be expressed by elliptic equation. The failure envelope, which can be used to inspect the limit instability of pile foundation, provides a basis to inspect the safety of pile foundation under horizontal load and moment load. The interaction between horizontal load and moment load must be considered in the design of pile foundation. 