收缩徐变效应下停工对连续刚构桥的影响研究

Study on Influence of Suspension on Continuous Rigid Frame Bridge under Shrinkage and Creep Effect

由于大跨度预应力混凝土连续刚构桥施工周期较长,在施工过程中会受到不可抗力因素的影响导致停工现象的出现,同时收缩徐变是影响连续刚构桥运营后期挠度产生的主要因素之一,需要对其进行监测控制。本文以实际工程为例,采用有限元软件对实际施工过程进行仿真分析,通过对理论值与实测值对比分析,探究因停工引起的混凝土收缩徐变效应对大跨度预应力混凝土连续刚构桥线形及应力的影响。结果表明,停工期间对结构的应力影响较小;收缩徐变效应下不同停工时间对桥梁挠度变化有重要影响;环境相对湿度变化和混凝土龄期是影响混凝土收缩徐变较大程度的因素。本文分析结果可为今后类似工程问题提供参考借鉴。

Due to the long construction period of long-span prestressed concrete continuous rigid frame bridge,it will be affected by force majeure factors during the construction process,resulting in the occurrence of suspension.At the same time,shrinkage and creep is one of the main factors affecting the deflection of continuous rigid frame bridge in the later stage of operation,which needs to be monitored and controlled.Taking the actual project as an example,this paper uses the finite element software to simulate and analyze the actual construction process.Through the comparative analysis of the theoretical value and the measured value,this paper explores the influence of the concrete shrinkage and creep effect caused by suspension on the alignment and stress of long-span prestressed concrete continuous rigid frame bridge.The results show that the suspension period has little effect on the stress of the structure.Under the effect of shrinkage and creep,different shutdowntime has an important impact on the deflection of the bridge.The changes of environmental relative humidity and concrete age are the factors affecting the shrinkage and creep of concrete to a great extent.The analysis results of this paper can provide reference for similar engineering problems in the future.