Analysis Of Plastic Components Lined With Underground Granary Under Water Pressure And Axial Pressure

With the advantages of constant temperature,keeping grain quality and resisting natural disasters,the new underground granary has gradually become an ideal type of green grain storage.However,as the granary is in the underground for a long time,it is easy to be eroded by the underground water,so the key problem of the safe storage of grain in the underground granary is to prevent water and moisture.In this paper,the lining plastic waterproof system is to connect the plastic waterproof board and concrete closely through studs.This method solves the problems of falling off of waterproof roll,easy decomposition and aging,and high cost of steel plate.The lining plastic waterproof system is composed of PP waterproof board,PP stud and PP connecting board.When local water seeps into between the PP waterproof board and concrete,water pressure will be generated on the PP waterproof board.At this time,the PP waterproof board is subject to the pressure generated by external water and soil pressure and the water pressure that seeps into between the PP waterproof board and concrete.In this paper,PP stud is selected with a diameter of 30 mm and a length of 100 mm,and the surface is treated with turning wire.The circular PP connecting plate adopts the disk with diameter of 90 mm and thickness of 30 mm.The thickness of PP waterproof board is 10 mm.The spacing of the bolts was set at 250 mm,300 mm and 350 mm,and the plastic lining waterproof members were made.To measure the maximum displacement and stress on the PP waterproof board,strain measuring points were arranged on the PP waterproof board and displacement measuring points were arranged on the outside of the PP waterproof board.Finally,concrete is poured and cured for lining plastic specimen,and axial pressure and water pressure are loaded after curing.In this paper,the stress and deformation of the lining plastic waterproof system under the joint action of water pressure and axial pressure are analyzed by means of test and finite element simulation.The main research contents and results are as follows:The limit of the water pressure of the lining plastic waterproof system with different stud spacing was obtained through experiments.The weak link of the lining plastic waterproof system was the position of the stud welding seam.When the stud welding seam was damaged,the stud spacing would increase larger,so that the ability of the entire waterproofing system to withstand water pressure decreased,and eventually the PP waterproof board would be damaged.In order to improve the ability of the lined plastic waterproof system to withstand water pressure,it can be achieved by improving the shear resistance of the stud weld and increasing the thickness of the PP waterproof board.The ABAQUS simulation software is used to model and analyze the test pieces.The axial pressure and water pressure of the model are loaded,and the change rule of stress and displacement is obtained through analysis.Compared with the test results,the finite element results are slightly larger than the test results,with a high degree of coincidence,which verifies the correctness of the finite element model,and provides some guidance for the waterproof and moisture-proof of the underground granary.