Rigid Frame Continuous Composite Girder Bridge Construction Control Research

With the continuous increase in bridge architecture, the continuous improvement in bridges spanning, the update and ameliorate in construction materials, machinery, equipment, technology etc, the development of continuous beam bridge construction rapid in China. Among them, the structural style of the rigid frame continuous composite girder bridge which combines the respective advantages of the continuous rigid frame and the continuous girder bridges, because of the force between continuous beam bridge and continuous rigid frame bridge,and both can increase the length in bridge applications and can adapt to the limit of short pier bridge environment,,has received the widespread attention and application.The rigid frame continuous composite girder bridge superstructure box girder use the cantilever construction technology, which has more construction section, long period,complex process and more difficult of construction. The strict construction control of in the process of bridge construction must be carried out strictly in order to ensure that the main bridge structure internal force and deformation is always in a safe range in the process of construction, and the bridge line can meet the design requirements, and structural dead load stress state close to the design expectations.This paper is relying on Dixi Tuojiang Bridge (reconstruction) engineering background, Fenghuang of Xiangxi Autonomous Prefecture in Hunan province, to review the history of development and the theory of the construction control of this kind of bridge.By using the BRanalysis and Dr.bridge to build composite bridges spatial model and simulation analysis, and to re-check the state of bridge and construction which is determined by design calculation.And proposed the following research contents:1. According to the actual construction characteristics of the Fenghuang Tuojiang Bridge reconstruction project, this paper introduces the basic control of the composite girder bridge construction monitoring theory and method, and analysis of its influencing factors2. The third pier of Tuojinag Bridge adopts expand foundation, others are pile foundations.To ensure the safety of the construction,this paper check the stability of the expand foundation, and analyses of the reasonable of its design.3. Based on Tuojiang Bridge, Establish the finite element model.Bridge line and stress is the key point of the bridge monitoring in the Cantilever construction.Based on the comparison of theoretical calculations with the measured values, this paper analysis of the variation rule of deflection and stress of main beam in shrinkage, creep, pouring, tension and other typical cases4. Because of various reasons, temporary consolidation of the first pier has been dismantled and a part of the sidewalk slab has been done before the side span of Tuojiang bridge closured, which brought difficulty to the construction control.In the light of the actual situation of the Tuojiang bridge construction, this paper analysis of the most appropriate time to dismantle the temporary consolidation and closure plan by compare the safety, bridge line, stress and other factors according to design requirements.