（浙江省建筑设计研究院， 杭州 310006）

［摘要］当基坑工程施工场地紧张时，基坑内支撑常设置运土车行走路线作为施工栈桥。移动荷载作用下的内支撑系统进行优化设计前必须先确定最大截面内力。以实际基坑工程为背景，利用软件ANSYS的APDL实现影响线的计算，比较各跨关键部位的内力，然后得到最大截面内力及相应出现的位置，以及该最不利位置对应的内力影响线和相应荷载作用位置。对于对称支撑系统，可先分析一跨作用移动荷载时的内力影响线，然后根据对称性确定另一跨移动荷载的作用位置，以及相应两跨均作用移动荷载时对应的最大截面内力。本研究也可供移动荷载下逆作基坑中楼盖结构复核承载力参考。

［关键词］内支撑系统； 影响线； ANSYS； APDL； 截面优化； 最不利位置

中图分类号：TU443文献标识码：A文章编号：1002-848X(2017)06-0080-06

Section optimization design of internal support system based on influence line

Zhou Pinghuai, Yang Xuelin

(Zhejiang Province Institute of Architectural Design and Research, Hangzhou 310006, China)

Abstract:When the foundation pit construction site is insufficient, the foundation pit support is often set up earth-mover route as the construction trestle bridge. The largest section internal force should be determined before the optimization design of the internal support system under moving loads. Based on the actual foundation pit project as the background, influence line was calculated by using the software ANSYS/APDL, and the internal forces of the key parts of each span were compared. And then the largest section internal force was obtained as well as relevant position. In addition, influence line of the most unfavorable position and the corresponding load position were obtained. The results show that for the symmetric support system, it is reasonable to analyze the influence line of internal force of the structure with moving load on one span, and then moving load position of another span can be determined according to the symmetry, and the corresponding largest section internal force of the structure with moving loads on both two spans can be determined. This study can be used as a reference for checking the bearing capacity of the floor structure in the reversed constructed foundation pit under moving loads.

Keywords:internal support system; influence line; ANSYS; APDL; section optimization; the most unfavorable position

作者简介：周平槐，博士研究生，高级工程师，Email:anji18@126.com。