Experimental Study And Analysis On The Flexural Behavior Of Concrete Box Girder Oriented To Double-deck Traffic

In order to solve the increasing traffic flow which is accelerated, the reality of urban land resources increasingly tense problem.This research combined with the concrete box girder structure of whole mechanical advantage,By reasonable improvement of common concrete box girder structure, make its roof and floor floor system, designed for double concrete box cross section beam bridge traffic,It is a kind of single box 3 rooms double deck traffic concrete box girder bridge, the upper deck design for motor vehicle road and pavement, the bridge for the urban light rail public transportation, the ministry of interior in box girder can decorate the city pipeline and cable, etc.In this paper, based on the double deck traffic in laboratory pouring the concrete box girder bridge 1:6 scale model experiment, has carried on the roof and floor of test model and loading process of the bending test,And calculated the bending properties of experimental model analysis, to explore their flexural properties and applicable calculation method,The main work completed the following aspects:(1) Test and research the whole process of the bending for the double traffic concrete box girder model,Received a test box girder cracking load, yield load and ultimate load, confirmed the wide span ratio, depth-span ratio are larger double traffic concrete box beam bending process can be divided into the elastic stage,elastic-plastic stage of development, final failure stage;Discussed the double deck traffic concrete box girder of the whole process of the bending load deflection curve,stress and strain and crack law of development.(2) The combination of domestic and foreign representative specification on double traffic model of concrete box girder deflection under normal use limit state,on the average crack spacing and crack width, the calculation result was consistent with the test result, Illustrate that through standard formula, analysising the deformation properties of the test model used in normal phase, crack width and the average crack spacing correctly.(3) Through the GB 50010-50010 standards and JTG D62-2004 specification for test box girder calculation and analysis of cracking moment and ultimate bending moment,Confirmed the test box girder using the GB 50010-50010 specification of cracking moment for i-section beam and ultimate bending moment formula calculated values and measured values are in good agreement, illustrates the test boxgirder can be equivalent to i-section beam, and then use GB 50010-2010 specification to design and calculate the bending performance related formula.