Research On The Characteristic Analysis Of Force And Deformation Of The New And Old Culvert Splicing And Engineering Technology Of Highway Culvert Widening

Currently, practical specifications and standards for extension of highway project are not yet mature, and the systematic study for culvert widening project is less, so culvert widening project studies of correlative technical issues are causing concern to academia and engineering technicians. Based on the summaries of research results about the highway culvert widening project at home and abroad in recent years, combining the Hui Shen highway extension and culvert widening project, the force and deformation characteristics of new and old culvert splicing site, design method and construction technology about culvert widening project are researched by using the numerical simulation and theoretical analysis. The main achievements are shown as the following:1. The force and deformation characteristics of new and old culvert splicing site of different conditions under two splicing methods are calculated and analysed by numerical simulation analysis. The results show that when using planting bar splicing, the adverse effect of new culvert to old culvert is larger than settlement joint splicing, and with widening span and filling soil height top of culvert increasing, the degree of adverse effect also increases; When widening span exceeds four meters and filling soil height top of culvert exceeds two meters, tensile stress of the middle and lower margin of old culvert cover plate in splicing site exceeds the design value of tensile strength of concrete edge, so the struction of culvert are destoried. But when using settlement joint splicing, tensile stress of the middle and lower margin of old cover plate in splicing site is littler than planting bar splicing obviously, and settlement different of new and old culvert is so small that it meets standard requirements.2. In the case of the settlement difference between new and old culvert foundation meet the requirements, to slab culvert and box culvert, when widening span exceeds four meters and filling soil height top of culvert exceeds two meters, settlement joint splicing between new and old culvert is recommended; In order to ensure splicing tightly, planting bar splicing is allowed. To pipe culvert and arch culvert, settlement joint splicing and rebuilding slab culvert are used correspondingly.3. The tensile stress of the middle and lower margin of old cover plate in splicing site of new and old culvert under one side widening is larger than both sides widening obviously. Recommended that both sides widening should be given priority in culvert widening, reasonable pile geometric parameters should be selected and used, integral foundation should be used in new culvert foundation and the size should be increased so that the settlement different of new and old culvert foundation meets standard requirements and the struction is not destorid.4. Construction techniques of highway culvert widening are summarized systematic, several engineering measures decreasing the settlement difference of new and old culvert foundation, detection methods and control standards of culvert widening construction quality are proposed.The research results on the one hand make the characteristics of the new and old culvert of different splicing methods clear, which provides a theoretical basis for the research of interaction of the new and old culvert; On the other hand, some scientific reference are provided for the designing and constructing technologies of highway culvert widening engineerings, and the research has a important practical significance.