多跨连续钢管混凝土拱桥拆除关键技术研究

Key Techniques for Demolition of Multi-Span Continuous Arch Bridge with Concrete-Filled Steel Tubes

以鉴湖大桥拆除工程为研究背景,对复杂情况下钢管混凝土拱桥的拆除进行研究,首先介绍了目前桥梁拆除的方法和应用现状,并结合该桥梁拆除的难点提出了3种拆桥方案,通过比选确定适用于该桥的拆除方案,对拱桥拆除的总体顺序进行说明,之后分析了各施工阶段的受力特性,对拆除中位移和应力的最不利阶段的理论值和实测值进行对比分析,最后研究了材料强度和温度对结构位移和应力的影响。结果表明:钢栈桥龙门吊法最适合于有通航要求且空间受限的桥梁拆除;翼缘切割后可增大两侧作业空间,减小梁体自重;腹板拆除过程中,结构的应力和位移值与梁体悬臂长度成正比;应力和位移的理论值较实测值偏小;材料强度和温度的变化不影响结构的受力规律,结构应力和位移与材料强度成反比,与温度成正比。

Taking the demolition project of Jianhu Bridge as the research background,the demolition of arch bridges with concrete-filled steel tubes under complex conditions was studied.First,the current bridge demolition methods and application status were introduced,and three bridge demolition schemes were put forward according to the difficulties of the bridge demolition.The appropriate demolition scheme for the bridge was selected after comparison,and the sequence of arch bridge demolition was explained.Then,the stress characteristics of the bridge at each construction stage were analyzed,and the theoretical and measured displacement and stress at the most unfavorable stage during demolition were compared.Finally,the influence of material strength and temperature on structural displacement and stress was studied.The results show that the gantry crane method for steel trestle bridges is best suited to the demolition of bridges with navigable requirements and limited space.After the flange is cut,the working space on both sides can be increased,and the self-weight of the beam can be reduced.During the demolition of the web,the stress and displacement of the structure are proportional to the cantilever length of the beam body,and the theoretical stress and displacement are smaller than measured values.The change of material strength and temperature does not affect the force law of the structure,and the structural stress and displacement are inversely proportional to the material strength and proportional to the temperature.