Study On The Highway Bridge Design Load And There Combination Effect

Bridge as the hub of the highway engineering, do an important position in the nationaleconomy occupies, and its security and the economy is not reasonable will cause the socialwealth great waste and a large number of state-owned assets loss, vehicle load is influencehighway bridge construction safety and applicability is one of the important factors. Alongwith the transportation demand and the continuous development of auto industry, vehicleoverload phenomenon is becoming more severe in recent years, appeared more craboverriding bridge accident, caused the social from all walks of life wide attention. In order tounderstand our country in recent years, highway bridge car load, and for highway bridge loadstandard to provide basis for the establishment of the project, the organization carries out anationwide car load research, and based on the research achievements of car load of thoroughresearch, made clear our country automobile load standard adaptability, the establishment of ahighway bridge car load standard formulation method. To load combination coefficient arestudied. Based on the statistical data of vehicles, the bridge vicle load centrifugal force wasstudied.This paper first in our country highway bridge car load existing prominent problems,both at home and abroad, car highway bridge load code and its research progress in theinvestigation and study analysis our country highway bridge vehicle operation status, loadcharacteristics, and reference, digestion, absorbs the domestic and foreign existingachievements in scientific research and application technology on the basis of results, and putforward four kinds calculational highway bridge car of standard values of windload of themethods: standard link method, probability statistics, historical experience method and themethod of laws and regulations. Standard link method is according to the foreign standardload mode and determination method, through the contrast analysis to determine our countryhighway Bridges in China in order to meet the requirements of the development oftransportation, Probability statistics is the automobile load as random variables, on the basisof the mathematical statistical analysis to determine the load standard; Historical experiencelaw is according to our country highway bridge car load standard formulation process, basedon the investigation of traffic conditions, in load standard fully considered and can reallyreflect the real models and load conditions; Laws and regulations method based ontransportation management policies, laws and regulations as the foundation, used to determinecar design load. Using the above methods respectively will load standard loading in two lane20m simply supported beam, the calculation method of four kinds of the load effect and itseffect on the comparative analysis to the current standard adaptability are analysed.Secondly, this paper in medium and small span bridge as the object of study, theevaluation in our country basic load combination of subentry coefficient and theircombination effect in the international status of the research of the partial coefficient value method. Select our country common medium and small span bridge as sample, combined withforeign highway bridge load standard and the partial coefficient, by the analysis andcomparison, determine the our country automobile load subentry coefficient value andcombination effect in international reasonable position. In vehicles measured data on the baseof the load on the mathematical statistical analysis, obtained the new statistical parameter.Through a given constant load effect of subentry coefficient, which use linde0.75linearseparation, general separation, resistance of least squares, reliable index least squares methodresearch the new car load effect of subentry coefficient value, and to a method the results andcomparison analysis are made. Based on the above work, based on the\"calibration method\"to the structure importance factor values of was studied.Finally based on the measured vehicle data statistics, determine the actual vehicle load ofvarious statistical parameters, to domestic and international vehicle centrifugal force standardspecification makes a comparative study. Based on the statistical parameters of the vehicle,prepare the random traffic flow simulation program, the use of centrifugal force calculationformula, use MATLAB under the random traffic automobile loading centrifugal force thetheoretical value of the simulation program. According to different radius of the centrifugalforce theory and numerical statistical parameters, get the car load centrifugal force probabilitydistribution function, according to the reliability theory, the different radius calculated basedon the measured under traffic car load centrifugal force standard value. Based on themeasured data of car load standard of centrifugal force and the centrifugal force standardstandard carries on the contrast analysis, and the results show that the current standardcentrifugal force and the actual vehicle statistics centrifugal force standard value in a certainextent does not adapt. Puts forward a new steam load centrifugal force of the standard valuevalue method.This paper research methods and conclusions can be for a new round of the load code forreference.