| Composite pipe gallery is an intensive tunnel that collects municipal pipelines centrally.As an important infrastructure for the construction of new towns in the 13th five-year plan,it has emerged in various cities in China.The traditional composite pipe gallery,whether it is cast on site or assembled prefabricated,is made of concrete material,which causes certain pollution to the environment in the construction process,moreover,the construction period is long,and later maintenance requires secondary excavation,so this has a serious impact on the daily life of residents.With the improvement of industrial level and the pursuit of life of green environmental protection,traditional composite pipe gallery has been gradually cannot meet the demand of the' reality.Therefore,this paper puts forward a new structure of fabricated steel-plastic composite pipe gallery,using the new material SMC and steel-plastic composite structure,the key structural parts and the overall mechanical properties of the pipe gallery were studied by combining computer simulation analysis and testing technology.The main research contents of this topic are as follows1.Introduces the effect of various additives in SMC material,material molding process and the basic mechanics performance parameters are given.According to the composite pipe gallery landfill force and based on the classical earth pressure theory,the mathematical relationship between the burying depth and soil pressure are established,and the problem of large deflection of thin plate is studied.It is concluded that the differential equation of the deflection and stress function,as to provide theoretical basis for the calculation and simulation analysis in the late2.Through theoretical calculation and simulation analysis of single piece of SMC,the design scheme of optimizing the flat plate into approximately equal strength arc-shaped plate was proposed.The final shape of SMC arc plate was determined based on the local loading analysis,soil retaining simulation and local loading test,which provided the key structure for the establishment of the following composite pipe gallery model.3.The simulation analysis model of pipe gallery was established.The equivalent stress and deformation distribution of the pipe gallery in the process of landfill and under the ultimate pressure were obtained.The variation trend of equivalent stress and deformation with the depth of landfill is analyzed and discussed,which provided the simulation analysis data for the buried performance tests of the pipe gallery.4.The mechanical properties of the composite pipe gallery were tested by means of electrical strain measurement.The collecting points were set up in the process of landfill,and the positions of the stress and deformation measuring points on the SMC arc plate and steel structure of the pipe gallery were reasonably arranged.Through measurement and calculation,the stress distribution and deformation degree of the pipe gallery are studied.Compare the simulation results with the test results,the accuracy of the simulation calculation is verified.After the completion of the landfill,the pipe gallery was monitored for 72 hours to test the short-term stability.5.The safety and reliability of the pipe gallery structure was analyzed by monitoring the deformation of the height and width of the pipe gallery,the deformation of two adjacent sections,and the relative deformation of the SMC arc plate to the steel structure for a period of six months.According to the damage of SMC arc plate after one and a half years of landfill,a preliminary analysis was made,and an improved scheme of pipe gallery structure was proposed. |
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