Quality Inspection And Evaluation Of Yu’an Section Of G105 National Highway

With the increase of vehicles and the increase of traffic flow,there will be many roadbed diseases,road surface aging,bridge structure defect or durability decrease after many years of use,resulting in a decline in driving comfort and capacity.The reconstruction of the old road is an important measure to improve the traffic conditions and improve the operation level of the highway.The economic principle should be considered in the reconstru ction of the old road,and the resources of the old road should be utilized as far as possible,such as making full use of the original roadbed,pavement structural layer,structural facilities,and so on.Therefore,in the early stage of reconstruction design,the evaluation of the present situation of the old road,the evaluation of the attenuation degree of the detection indexes of the old road and the formulation of the treatment measures can provide objective and scientific data support for the design plan of the reconstruction project.Combined with the basic methods of detection and evaluation of old roads at home and abroad,the reconstruction design stage is usually dominated by the macro factors of the project,and the utilization of the surplus v alue of the old roads is insufficient.As far as the current domestic standards and codes are concerned,apart from highway maintenance codes,engineering design and construction codes,there is not yet a complete theoretical system for quality inspection of old road reconstruction projects,except that some testing contents related to reconstruction projects are mentioned in engineering design and construction codes.In order to make rational use of old road in reconstruction project,it is necessary to pr ovide effective data for design and reconstruction from the quality status of subgrade engineering,pavement engineering,bridge and culvert engineering,and through the inspection,evaluation and treatment suggestions of above engineering quality.In order to determine the soil quality and dry-wet type of roadbed soil,the physical and mechanical properties of roadbed bearing layer soil,such as density,liquid-plastic limit,self-expansion ratio and so on,are measured in the range of0～150cm depth by core-drilling method in the old roadbed engineering.In the process of reconstruction design,the relevant indexes of geotechnical test are used to calculate and analyze the size of subgrade bearing capacity,the geological conditions and so on.The starting point of reconstruction projects is usually to improve the grade of highway and improve the quality of operation.Therefore,the detection of the old road pavement engineering should be carried out from the pavement damage and strength,quantitatively eva luate the old road pavement damage,bearing capacity level,and take the corresponding maintenance and reinforcement measures,so that the old road structure layer in the later reconstruction can be reasonably utilized.The quality of bridge and culvert structure is closely related to traffic safety.The quality of the old bridge not only satisfies the service performance of the old road,but also meets the demand of the load and capacity after the reconstruction of the highway.In view of the reconstructi on project,the quality inspection of the old bridge is firstly analyzed from the appearance defect,the material performance,and the grade of bridge technical condition is evaluated.It is necessary to evaluate the bearing capacity of the old bridge in o rder to determine whether it can meet the requirement of the capacity after reconstruction for the bridge which needs to be improved in the design load of the reconstruction project.According to the test results,make the corresponding design plan and tak e the corresponding maintenance and reinforcement measures.In order to meet the long-term traffic demand of the reconstruction project,it is necessary to investigate the traffic volume of the old road when designing the capacity of the road.This paper makes statistics on all kinds of vehicles passing through the prescribed section in different periods of the old road,and compares the corresponding grade highways in the design code,which can provide reference for the design of the cross-section of the route.In this paper,a quality inspection system for reconstruction of the old road is worked out in combination with an example of the old road reconstruction project in Yuan section of the G105 National Highway.Based on the characteristics of reconstruction project,this system puts forward the work content of testing the current situation of old road quality,analyzes and evaluates the residual value of old road,and puts forward the corresponding treatment measures.The system has played a good role in the quality inspection of the project.