张继红  王国体
       (合肥工业大学土木工程系 合肥 230009)

[提要]  提出通过附加应力计算基坑支护问题，给出了土体中的静力反算关系式，考虑开挖前原位土体中应力作用以及地面堆载、基底开挖卸载的影响，建立平面有限元法及土抗力法计算的静力反算荷载模式。结合实例计算，说明方法可供实践参考应用。
[关键词]  附加应力  原位土中应力  基坑支护 荷载模式 有限元法 土抗力法

Authors introduce how to use additional pressure for retaining structures calculation in excavation. A formula is given to reflect the relationship among actual stress, origin stress and additional pressure in earth during excavation. With reference to the origin stress insoil, surface load and unloading effects on the base of foundation, two load distribution models are introduced for finite-elenent method and subgrate reaction method. The application of the models is demonstrated via a study of two published historical cases. It is found that the model is applicable for engineering practice.
Keywords: additional pressure;origin stress; retaining structures;load distribution model; finite-element method; subgrade reaction method.