Research And Application Of The Grillage Method Used On Multi-room Wide Girder Bridge

With the high-speeding development of economy, our modernizationconstruction on traffic is stronger and stronger, as well as the technology of bridgeconstruction, emerging many new-style bridge structure forms, the horizontal widthof bridge is increasing, which caused higher demanding on project design. Cantileversingle-room broad box girder sections is a widely used cross-sectional form oncurrent bridge, especially used at the urban trunk road such as highway and bridge. Ithas excellent structural stress performance, but with disadvantages of large abdominalplate spacing, wider horizontally flange, thinner box wall and so on. When design forit’s structure, the mechanical performance of thin-walled box girder structure wall isusually complicated, except for the shear, it will also associated with reverse warping,distortion on the cross-section. Given the particularity of the single-box multi-roomwidth box frame, the existing theory for single-box single room box frame is not ableto calculate effectively, therefore it’s necessary for further study, to find a calculationmethod which suitable for single-box multi-room width box frame.When it comes to analysis the construction of wide box girder, skew bridge,curved bridge and so on, grillage method is a effective space analytical method forbridge construction, which usually used on current design and scientific research, iteasier control, can guarantee a enough accuracy on design, among them the mostadopted method is shear-flexible girder method. Establishing an equivalent grillagesystem to simulate bridge upper structure, having the advantages of wide applicablecondition, high computational efficiency, reasonable accuracy, also the output meetsthe current highway bridge design standard, which will be widely used in futurepractical engineering.This article firstly describes the development of wide box girder bridge at homeand abroad, discusses the applicable scope, advantages and disadvantages separatelyfor each research method, clarifies the idea that grillage method is a effective analytical method for analysis wide box girder bridge; Then introduces finite elementunit analysis method for space frame, considers six freedom degree for each node ofspace frame unit; Has a discussion focusing on the basic method of using grillagemethod to grid tumble multi-room width box frame structure, the value issue forgrillage stiffness, as well as research and compare several key issues of grillagemethod, also puts forward a new calculation method of longitudinal division on crosssection; In the end, regards an static load test of actual concrete continuous wide boxgirder bridge as engineering background, uses finite element software Midas/Civil toset up model of grillage method, and verifies the stiffness values reasonability ofgrillage method model using Midas/FEA setted entity unit model, in the end, analysisand compares date of static loading test with test result of grillage method model.The analysis found that model of grillage method can reflect the loading featuresof actual Bridge Structure in a degree, approving the grillage method merits of clearconcept and easy to be calculated, it’s a effective way to analysis wide box girderbridge, has practical significance on engineering, also laid the foundation for furtherrefined structural analysis of box-girder Bridge program.