附加变形对沪通长江大桥行车性能影响

Performance Influence of Train Driving on Shanghai-Nantong Yangtze River Bridge Considering Additional Deformation

研究目的:以沪通铁路公铁两用长江大桥主桥为背景,通过在车线桥耦合振动分析中将上层高速公路活载作用及温度作用产生的附加变形叠加到轨道不平顺中,考虑附加变形曲线对铁路列车通行的影响。通过对比各附加变形工况下的车桥系统动力响应指标,来评价附加变形曲线对此类桥梁的行车性能影响。研究结论:(1)桥梁的横向位移在公路活载附加变形下几乎没有变化,而在温差附加变形下由6.453 mm增加到7.332 mm,增幅约14%;(2)桥梁的竖向位移在各种附加变形下几乎没有改变;(3)在各种附加变形下,列车的脱轨系数、轮重减载率、竖向及横向加速度,以及平稳性指标几乎没有变化,但在10℃温差作用下的轮轨力由18.552 kN增加到19.371 kN;(4)本研究成果可为千米级超大跨度公铁两用斜拉桥的设计提供参考。

Research purposes： Taking Shanghai -Nantong super- long- span （142 ＋ 462 ＋ 1092 ＋ 462 ＋ 142）m highway and railway cable - stayed hridge as an engineering background, the additional deformation induced by the upper highway live load and temperature effect was considered in the analysis of process of train - track - bridge coupling system to assess the impact to performance of running train. By comparing the vehicle bridge dynamic response indexes under the condition of various additional deformation, the impact to traffic performance was evaluated. Research conclusions： （ 1 ） Transverse displacement of the bridge under the additional deformation induced by live loads of highway was almost unchanged, as it increased from 6. 453 mm to 7. 332 mm under the additional deformation of temperature difference, rising by about 14%. （2） Vertical displacement of the bridge under various additional deformation has almost no change. （3） When considering various kinds of additional deformation, the derailment coefficient, the wheel unloading rate, the vertical and lateral acceleration and riding index of the driving train had barely changed, but under the effect of 10℃ temperature difference, the wheel/rail force increased form 18. 552 kN to 19. 371 kN. （4） The research results could provide references for engineering design of super -long -span highway -railway cable - stayed bridge.