基于墩柱支承变刚度模型的某轻轨连续梁桥差异沉降分析

以某轻轨连续梁桥为实证背景,提出了固定支座模型和墩柱支承变刚度模型,固定支座模型采用强迫位移法直接求解,墩柱支撑变刚度模型采用优化反分析法迭代求解,目的是分析轻轨连续梁桥墩台差异沉降特性。分析表明:(1)固定支座模型的沉降仅发生在主动沉降墩,墩柱支承变刚度模型在主动沉降墩沉降时,也引起影响区其余墩柱沉降;(2)墩柱沉降会导致墩柱支反力显著变化,且计算模型对其有一定影响,总体规律是主动沉降墩对应支反力减少,相邻墩柱支反力增加,间隔墩柱支反力变化幅度受主动沉降墩沉降量影响较小;(3)采用固定支座模型时,墩柱沉降与梁截面弯矩变化呈线性关系,采用墩柱支承变刚度模型时,二者呈非线性特性。

Differential Settlement Analysis for Light Rail Continuous Bridges Based on Variable Stiffness Model with Piers-Supported

The fixed bearing model (FBM) and variable stiffness model (VSM) with piers-supported of a practical light rail continuous bridge are proposed. The FBM is solved using the forced displacement method, and the VSM is solved by iteration using the Optimum-back analysis method. The purpose of the study was to analyse the properties of differential settlement of the light rail continuous bridges. Results show as follows: 1) The settlement only occurs in the active settlement pier itself for the FBM, while the settlement of the active settlement piers will cause the settlement of the other piers for VSM; 2) The settlement of the piers will give rise to the significant change of support reaction, which is also influenced by the analytical model. Particularly, the settlement will lead to the decrease of reactive force of the active settlement pier and increase of the adjacent piers. The influence of the settlement of active settlement pier on the variation of reaction force of interval pier is inconspicuous; 3) The relation between pier settlement and variation of moment is linear for FBM, while nonlinear for VSM.