The Performance Analysis Of Semi-integral Bridge

Expansion device is easily damaged for exposion to severe environmental conditions, whichleads to high cost of human and material resources. To solve this problem, we lengthen thecontinuous part to minimize the amount of expansion joints, or directly remove theexpansion joints, which can not only greatly reduce the cost of construction andmaintenance, also improve the comfortable level of riding and decrease the vehicles’impacton bridges. The integral abutment bridge emerges as the times require, however the integralabutment bridge show a lot of insurmountable problems, which leads to the birth ofsemi-integral bridges. The paper mainly focus on semi-integral bridges, the main work is asfollows: Based on a (5×25)m continuous beam bridge transformed from simply-supportedstructure and self-designed semi-integral abutment joint, finite element model is built withMidas Civil, in which superstructure is modeled with elastic space beam grillage method,soil resistance is modeled with nodal elastic support, and bearings are modeled with elasticsprings. Firstly, the influence of uniform temperature, temperature gradient andshrinkage-creep on the structural internal force and deformation response is analyzed, theresult indicates that the moment, axial force and longitudinal displacement of girder isgreatly affected by temperature rise, longitudinal and vertical displacement, axial force ofgirder and pile moment are sensitive to shrinkage-creep. Secondly, the structural calculationof the semi-integral bridge is performed under the state of ultimate limit state, service limitstate and the stress of the girder under permanent situation according to the currentspecification. The difference between the semi-integrel bridge and conventional beambridge is that axial force induced by temperature rise should be considered to ensure thesafety of the structure. Lastly, parameter study is conducted on the semi-integral bridge.The parameters mainly include temperature, height and thickness of parado and the rigidityof backfill. Reasonable value of these parameters is also recommended in the analysis. Theadvice to design and construction of the semi-integral bridge is also put forward, which ishelpful for later research and provide support for its popularization in China.