Ratio Orthotropic Plate Lenticular Multi-chamber Thin-walled Box Girder Structure Mechanical Performance And Test Large Wide Span

A new type of streamlined girder (lenticular cross section) bridge with thin-walled steelbox girder is proposed in this paper. The main characteristics of this bridge are thin-walled,multi-cell, with large width-span ratio and that use orthotropic top/bottom/longitudinal-diaphragm plates. The aim of this study is to investigate the effect of the wholebehavior in thin-walled box girder bridges with large width-to-span ratios through bothexperimental and numerical studies. In the same time, several sifferent simple analysismethord are discussed. The main work in this paper is as follow:A large-scale Plexiglas model is tested under different loading cases. The materialparameters are obtained from physical characteristics tests and tensile tests. The deflectionsand strains in each control section are tested. It is the first time to test this whole bridge modelof streamlined girder (lenticular cross section) bridge with thin-walled steel box girder.Inaddition, two different stimulation models were introduced. It is illustrated that the propertiesof this class of bridges. The stress distribution in top plate and bottom plate between adjacentwebs and diaphragms are compared. It is a good reference to the future application of thistype of structure.One theritical methord is presented to analysis the shear lag effection in this bridge. Basedon principle of minimum potential energy, a cosine function is defined as warping function.Then, a control differential eguation are induced by variation method. Finally, the stress anddeflection general formulas of a two spans continous mutil-cell box girder are given. Basedon the testing, shear lag of top plate and bottom plate in a two spans continous five-cell boxgirder are analyzed. It is the first time to study the contribution of streamlined web to thewhole structure in shear lag.The steel plate is considered as a shell, thus the analysis can be separated into two parts:one is the problem of the plane stress, the other is the theory of the thin slab bending. Thestructure with continuous longitudinal stiffened box girder bridge is converted to ananisotropy material plate with uniform thickness. A new finite element determinant is builtand programmed. Based on the continuous longitudinal stiffened box girder bridge, thecomparative analysis among fined finite element model, experiment model and thecomputational method in this study has been investigated. The results show that thecomputational method in this study can meet the engineering requirements and save too muchtime in modeling and post processing.In order to adjust the stiffness ratio of the traditional orthotropic bridge deck as well as thepavement overlay. In this paper, an orthotropic steel bridge deck stiffened with the pavementoverlay is analyzed. The pavement consists of the cement-based and asphalt-based overlays. Several parameters are choosen to analysis the structural mechanics utilizing thefinite-element method. Then, the porper range of each parameter is given.Optimal design is seek to satisfy all performance requirements as well as to minimize thecost of construction. With high-speed computers, finite element methods, and efficientoptimization algorithms, structural optimization techniques have expanded for the design ofadvanced and complex structures. Based on the the grillage method in optimal design, thesteel consumption is choosen as the object function. There are seven parameters, such as thedistance between adjacent diapgragms, the thickness and height of diapgragm and stiffeningrib, the number of the stiffening rib and the thickness of the top plate. The constraintconditions are the deflection and allowable stress. The final values of the optimal parametersare given.