Research And Application Of Field Assembly Culvert

The fabricated structures have been widely used in irrigation and water conservancy in recent years because of the advantages of simple construction,shortened construction period and saving money.But at the same time,due to the lack of scientific and unified norms,the problems of heavy prefabricated components,uncommonly used components and inconveniences of assembly still exist to a certain extent.Therefore,the research on the structural form of field fabricated structures,the strength of the components and the suitability of concrete mix proportion is of great theoretical significance and practical value.Based on the research of Yangzhou University in 2011 to develop a new type of fabricated small watergate(patent no.:ZL 2011 2 0499616.X),in order to make the patent practical application as soon as possible,in the following aspects of research work:(1)Under the condition of meeting C25 concrete strength requirement,finding the suitable ratio of foam concrete,to achieve the purpose of light quality and high strength,foam concrete is formed by adding foaming agent,fly ash and silica powder on the basis of traditional concrete building materials.Based on the test indexes of concrete test blocks 28d strength and bulk density,the experimental factors were determined by the determination of fly ash,silica powder and foaming agent,and three experimental levels were selected for each factor,and the orthogonal table was constructed.The combination ratio is determined by orthogonal test,and under the conditions of the laboratory,the compressive strength and bulk density of different concrete test blocks under different conditions are obtained.Secondly,according to the orthogonal test results,the concrete mix ratio of the concrete test block is determined by orthogonal analysis.Finally according to the analysis results,the results are verified and the correctness are determined.The research results show that in the range of 10%?30%dosage of fly ash,3%?9%dosage of silicon powder and 1.0%?2.0%dosage of foaming agent,under the conditions of three levels of discrete,meet the requirements of the optimal mixture ratio to 20%dosage of fly ash,9%dosage of silicon powder,1%dosage of foaming agent.(2)Taking ?80 culvert head commonly in engineering as an example,whether the thickness of the bottom of common field culvert can meet the requirements is determined by force analysis of field fabricated culvert and ascertaining the reserved slot depth of small culvert retaining wall inserted into bottom plate;Through the modeling by finite element software Abaqus,global stability,structural strength and so on are studied and whether the concrete compressive strength and tensile strength of the culvert head floor,retaining wall and wing wall structure meet the requirements is determined.The results show that taking 20cm as the thickness of the bottom plate of C25 concrete sluice culvert can meet the requirements,and the overall stability and structural strength of the field culvert can meet the standard requirements.(3)Through the finalized design of the field culvert section,this paper determines the size of common field culvert section in the construction of farmland water conservancy project.According to the calculation result,when the field culvert control area of 100 acres or less,? 40 is used;?60 is adopted in the area of 100?300 acres;Using ?70 in the area of 300?500 acres;Using ?90 in the area of 500?800 acres;Using ?100 in the area of 800?1000 acres.