Research On The Load Transverse Distribution Of Double-Curved Arch Bridge

The double-curved arch bridge was first built by Chinesebridge-constructors in1964. This kind of bridge has the advantages of savingreinforcing steel bars, low cost, structure simpleness, constructionconvenience, good spanning ability. Therefore, this kind of bridge was widelyused in our national bridge construction in the60th to70th of twentieth century.By1979, the number of double-curved arch bridges in China had amounted to4085,the total length reached350thousand meters, and accounting for25.7%of largeand middle bridges in China.So far, this kind of bridge has gone through the service period of40years,and as the extension of the service time, different levels of damage haveoccurred to this kind of bridge. From some related investigation data of thiskind of bridges, the main forms of the damage of this kind of bridge are as follows:poor arch ring integrity, inadequate arch ring section, misdeal of spandrelconstruction and base displacement.From the deep analysis of the damage in double-arched arch bridge, the poorarch ring integrity is the main damage of the bridge. The arch ring of thedouble-curved arch bridge is composed of one or more small arches. Thelongitudinal and transverse directions all assume the shape of arch whosestructure has a certain complexity. Different from the general board archbridges, the double-arched arch bridge has obvious space mechanicalcharacteristics. In the calculation of double-curved arch bridge, the spacefunction of the load should be taken into consideration. Therefore, it ismeaningful to clear the transverse mechanical characteristic in the design,inspection and reinforcement of this kind of bridge. Many scholars at home andabroad make relevant researches on the load transverse distribution coefficient of double-curved arch bridge. Based on a sort of assumption, the calculationmethod of the load transverse distribution coefficient is presented. For example,the ministry of communications highway research institute presents the elasticsupporting continuous beam method; Professor Jin Chengli presents the loadtransverse distribution calculation method of thrust system considering thelongitudinal displacement; Professor Li Guohao analyzes and induces the archload transverse distribution calculation method; Tongji University regards thearch ring as the space structure with crossing longitudinal arch ribs and lateralclapboards and uses the finite element method to analyze the arch ribs. Thetransverse distribution of the double-curved arch bridge is affected by manyfactors, such as spandrel construction and damage. The influencing law of thesefactors on the arch bridge transverse distribution is not clear. So, it’smeaningful to study the transverse distribution characteristics, discuss theinfluencing laws of different factors on the double-curved arch bridges, presentproper calculation method of double-curved arch bridge transverse distributioncoefficients, in order to perfect the calculation theory of this kind of bridge.This paper is based on a double-curved arch bridge in Lining Province, theresearch word conducted are as follows:(1) Analyze and conclude the load transverse distribution coefficientcalculation method. Compare the three different calculation methods, which areEccentric Compression Method, elastic supporting continuous beam method, andspace numerical computation method, and clear the applicability, advantages anddisadvantages of these calculation methods.(2) Based on fundamental theory of the finite element method, thetheoretical analysis model of the double-curved arch bridge is built.Respectively calculate the load transverse distribution under the conditionsof regardless of bridge deck pavement, considering bridge deck pavement anddifferent thicknesses. Based on the calculation results, discuss the effectsof the existence of bridge deck pavement on the double-curved arch bridge load transverse distribution and make researches on the thickness of bridge deckpavement on the double-curved arch bridge load transverse distribution.(3) Conduct the static load testing to the practical project, and measurethe displacement and strain of each arch rib under load. Analyze the loadtransverse distribution of the practical project based on the testing results.Compare and analyze the measured values and theoretical values of the loadtransverse distribution. The comparison results verify the reliability andvalidity of the numerical analysis method proposed by this paper.