独塔双索面斜拉桥荷载试验研究

Experimental Study on the Loading of One-tower Double Plane Cable-stayed Bridge

为准确评估斜拉桥成桥时的承载能力及工作状态,检验桥梁结构是否达到设计及有关规范规定的要求,为桥梁交工验收提供技术依据,以沥桂大桥(独塔双索面预应力混凝土斜拉桥)为研究对象,采用Midas Civil建立了斜拉桥有限元模型,介绍了斜拉桥荷载试验检测的主要测试断面及测试内容,对比分析了主梁应变、挠度、主塔塔顶纵桥向水平位移、索力增量等静力理论计算值与实测数据,并对该桥的自振特性及动力特性等动力荷载试验进行了分析。结果表明:1)该桥各项静载试验参数、校验系数均在规范要求的合理范围内,相对残余均小于20%;2)结构的自振频率、阻尼比及动力响应均处于正常工作状态,该桥整体处于弹性工作状态,受力状态良好,满足设计荷载及有关规范的使用要求。

In order to accurately assess the bearing capacity and working condition of the cable-stayed bridge when it is completed,to check whether the bridge structure meets the requirements of the design and relevant norms,and to provide a technical basis for the bridge handover acceptance,this paper takes Ligui bridge(one-tower double plane prestressed concrete cable-stayed bridge)as the research object.Midas Civil was used to establish the finite element single girder model of the cable-stayed bridge.The paper mainly introduces the main test section and test content of the load test inspection of cable-stayed bridge.A comparative analysis was done on the static theoretical calculations and themeasured data of the main girder strain,deflection,longitudinal horizontal displacement of the top of the main tower tower,cable force increment.And the self-oscillation characteristics and dynamic characteristics of the dynamic load test were analyzed.The results show that:1)the bridge static load test parameters calibration coefficients are within the reasonable range of specification requirements,the relative residual strain is less than 20%;2)The self-oscillation frequency,damping ratio and dynamic response of the structure are in the normal working state.The bridge is in the overall elastic working state with a good force state,which meets the design loads and the use requirements of the relevant codes.