建筑承重系统上的作用

Actions on building load-carrying system

目前的“作用”概括了建筑承重系统部分状态变化的原因。本文根据长期的工程实践和目前的耐久性研究推广了作用概念，将其定义为所有引起系统几何、力学、物理、化学状态变化的原因，并具体讨论了作用的类别，以及作用和作用效应的内外关系，提出复合效应概念。

The present concept of action summerizes reasons of variation of some states of building loadcarrying system. Based on long historic engineering practice and present research on durability, concept of action is extended in this paper, which is defined as reasons of variation of all states, including geometric,mechanistic, physical and chemical states, of building load-carrying system. Then a discussion is made on classification of actions, and initial and mutual relations between actions and action-effects, and a new concept of compounded action-effect is proposed.