In-Situ Testing And Numerical Simulation Study On Prefabricated Reinforced Concrete Culvert

As a new underground culvert structure, the prefabricated reinforced concrete culvert with the advantages of being easy-control the project quality, construction speed and low cost has the widespread application value and prospect. It can be bulk prefabricated in the factory and transported to the site to install. Anhui province will push the application of the prefabricated reinforced concrete culvert to the Liu(an) Wu(han) expressway and Si(xian)Su(zhou) expressway and other projects.Whereas the domestic research on the application technology of segmental prefabricated underground culvert is still blank and there is no design specification to offer for the reference. With the inadequate working experience, design and construction methods are just on the initial stage.Combined with the subject that approved by Anhui Provincial Communications department and Anhui Traffic Investment Group's research project , this paper uses in-situ test, theoretic analysis and numerical stimulation to do a deep systematic research on the mechanical properties, seismic design and construction process of prefabricated reinforced concrete culvert. The main research work containing some aspects are as following:(1) To monitor the dynamic construction process of the prefabricated reinforced concrete culvert. Based on the in-situ field measured data, this paper makes a thorough study of the earth pressure, deformation, stress and foundation settlement distribution and development law of prefabricated reinforced concrete culvert in the phrases of constructing.(2) Using the large universal finite element program ANSYS as the platform, this paper presents a three dimensional solid contact calculation model of the prefabricated reinforced concrete culvert and simulates the entire process of hoisting and backfilling of prefabricated culvert by the application of"element birth and death". Using the model to analyze the deformation and stress distribution of a prefabricated culvert of Liu(an)Wu(han) expressway and comparing the calculation results and field measurement record, this paper verifies the accurate and feasibility of the model and result.(3) A space finite element model of skew prefabricated reinforced concrete culvert is established. Skew prefabricated reinforced concrete culvert loaded under the vehicles, the deformation size of different skew culvert and the stress size and the distribution of stress have been analyzed in this paper.(4) Based on the research of a prefabricated reinforced concrete culvert of Anhui Si(xian)Su(zhou) expressway and considered the priciple of soil-struction interaction and the friction and extrusion between segment joints, this paper discusses and studies the key issues relating to the location of splitting point of segment joint and the bad position for the location of loaded vehicles by using finite element numerical simulation technology to establish a two-dimensional finite element model for the culvet.A three dimensional solid contact calculation model of the culvet is established to calculate the size and the distribution of its stress. Comparing with the results calculated by the two-dimensional finite element and the result of three dimentional, it shows that the two results are nearly the same.(5) Imposing viscous spring artificial boundary in the boundary of the soil to set up a dynamic analysis model for a prefabricated reinforced concrete culvert in Si(xian)Su(zhou) expressway project and using the time-history analysis method, this paper makes a thorough study on its nonliner seismic response and studys the law of horizantal displacement and internal force of the prefabricated reinforced concrete culvert under the coaction of static load and horizontally seizimic loading.(6) Combined with the road and railway constuction experience of domestic and foreign culverts and underground passages structures and the prefabricated reinforced concrete culvert construction practice of Anhui Liu(an)Wu(han) expressway project, this paper concludes the construction technology that suitable for China's prefabricated reinforced concrete culvert construction and presents the corresponding consturction requirements.