中文摘要：

宁波南站枢纽改建工程的深基坑工程采用一座临时铁路桥维持既有线运营，线下基坑与其他区域基坑同步开挖，为保证基坑开挖过程中临时铁路桥的运营安全，该桥设置实时动态安全监测系统。以宁波南站枢纽改建工程临时铁路桥为研究对象，基于ANSYS平台，采用点-点接触单元结合“位移耦合法”编制系统非线性动力响应分析程序，基于ANSYS文件管理功能和重启动分析功能，编制考虑非线性影响的摄动法动态特征值分析程序，分析该临时桥在最不利基坑开挖阶段下列车运营的动力稳定性，为该桥的动态监测工作提供重要依据。

英文摘要：

A temporary bridge was built to maintain the operation of existing railway line in the deep excavation project of the construction of NingBo South Station hub transformation, to realize the synchronous excavation of foundation pit under line with other region. A real - time dynamic safety monitoring system was established to ensure the operation safety of this temporary railway bridge during excavation. Taking the temporary railway bridge as the object, the nonlinear dynamic response analysis procedures using point to point contact element combined with ＂ displacement coupling method＂ was proposed based on ANSYS in this paper, and the perturbed nonlinear dynamic stability analysis procedures was programmed by means of the function of file management and restart analysis in ANSYS. The dynamic stabilities of this temporary bridge under the most disadvantageous stage of deep excavation were analyzed, which provides evidence for the dynamic monitoring of the temporary bridge.