影响繁忙干线框构桥顶进效果的因素分析

发布时间：2018-03-25 06:19

本文选题：框构桥　切入点：顶进施工　出处：《铁道工程学报》2017年05期

【摘要】：研究目的:框构桥作为后建铁路与公路穿越既有线时平改立的主要形式之一,在顶进施工过程中,各施工参数及工程条件会导致既有线轨道及路基的几何形位变化,对既有线上列车的安全运营产生不利影响。本文以既有津山铁路线下框构桥顶进工程为研究对象,采用MIDAS/GTS有限元软件,建立框构桥顶进施工模型,分析影响框构桥顶进效果的影响参数,并与现场监测结果进行对比,探讨施工参数和工程条件对既有线路基沉降、轨道水平及路基水平位移的影响规律。研究结论:(1)开挖进尺对既有路基沉降的影响显著,开挖进尺越大,路基沉降越大;(2)提高注浆强度能有效控制路基沉降,注浆强度每增加10 MPa,路基最大沉降量平均降低约10%;(3)顶进力是引起既有路基水平位移的主要原因,顶进力每增长50 kPa,水平位移增长约30%;(4)框构桥跨径、埋深及填料弹性模量对路基沉降、轨道水平及路基水平位移均有较大影响,且均随跨径的增大及埋深和填料弹性模量的减小而增大;(5)该研究成果可为同类框构桥工程的设计提供借鉴。
[Abstract]:Research purpose: frame bridge is one of the main forms of horizontal reconstruction of the post-built railway and highway crossing the existing railway. In the process of jacking construction, the construction parameters and engineering conditions will lead to the change of the geometry and position of the existing railway track and subgrade. This paper takes the frame bridge jacking project under the existing Jinshan railway line as the research object, and establishes the frame bridge jacking construction model by using MIDAS/GTS finite element software. The influence parameters affecting the jacking effect of the frame bridge are analyzed, and compared with the monitoring results on the spot, the settlement of the existing railway roadbed under the construction parameters and the engineering conditions is discussed. The influence law of track level and roadbed horizontal displacement. Conclusion: 1) the influence of excavation ruler on the settlement of existing roadbed is remarkable, the larger the excavation advance, the bigger the roadbed settlement is (2)) increasing the grouting strength can effectively control the subgrade settlement. For every 10 MPa increase in grouting strength, the average maximum settlement of roadbed is reduced by about 10 ~ 3%) the main cause of horizontal displacement of existing subgrade is that the jacking force increases 50 KPA, and the horizontal displacement increases about 30 ~ 4) frame bridge span. The depth of burying and elastic modulus of filling have great influence on subgrade settlement, track level and subgrade horizontal displacement. With the increase of span and the decrease of burying depth and elastic modulus of fillers, the research results can be used for reference in the design of similar frame bridges.
【作者单位】：北京交通大学;北京市重大项目建设指挥部办公室;天津市市政工程设计研究院;津滨城际铁路有限责任公司;
【基金】：中央高校基本科研业务费专项资金(2015JBM064)
【分类号】：U445.4

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