Study On Construction Crack Analysis And Control Measures For Layered Casting Concrete Box Girder Bridge

In the modern foundation for bridge construction, concrete continuous beam bridgeis widely used due to its advantages achieved very good results in the the operation of thebridge. With the continuous development of prestressed continuous box girder, someproblems emerged, of which most is the cracking of the box girder, some bridgeconstruction cracks. These cracks not only affect the appearance of the structure, but alsodamage the bearing capacity of the bridge, affect the durability of the bridge.In this paper, a seat support construction of prestressed concrete continuous beambridge, through the analysis of influencing factors of the construction process of thebridge to determine the parameters affecting the construction cracks, and simulate thestress condition of the concrete box girder under different parameters, and then comparethe maximum tensile stress The concrete tensile strength values in order to determinewhether the structure of cracking. Through simulation analysis of the concrete beambridge may be cracks in the situation, focus on prevention in the construction Summarycrack control measures and construction guidance. Research as follows(1) The use of finite element analysis software Midas calculated based on theproject in the second pouring force status, bottom webs built in the form of open boxgirder roof converted into a uniformly distributed load is applied in the model, andcoercive displacement analysis of box girder in the different displacement of the bottomplate of the situation by force, to draw concrete ultimate tensile stress exceeds the tensilestrength of the critical displacement, and take appropriate measures to prevent too largedisplacement in the construction.(2) By changing the temperature gradient and humidity based on the project modelto simulate the concrete shrinkage deformation of the beam cross-section internal force,the force analysis of different temperatures and humidity box girder judge twice pouringcontact surface whether there will be cracks in the roof concrete pouring of the heat ofhydration and find a time period for conservation to reduce the temperature cracks.(3) Based on the project is a long structure in the prestressed tension, prestressedrelatively large loss of use the Midas software simulation of non-symmetrical tensionand loss of prestress force structure to guide the tension construction.(4) In this paper, the process of prestressed continuous box girder cracks factorsaffecting the simulation analysis based on the prevention and control continuous boxgirder cracks effective measures to guide the construction.