Analysis Of The Failure Mechanism And Upgrading Of Solar Greenhouses In The Guanzhong Area

Facility agriculture is an important means of promoting agricultural modernization and an effective way to increase the economic income of farmers.Sunlight greenhouses are an important component of facility agriculture and have been widely used in northern China,bringing significant benefits.The solar greenhouse industry in the Guanzhong area of Shaanxi Province has shown a good trend with technological development,but there are still shortcomings in terms of technological level,design,construction,and daily maintenance.During research,it was found that most solar greenhouses have structural and component failures,and the greenhouse is even more severely damaged when encountering extreme weather.This article focuses on the failure phenomenon of the walls and frameworks of solar greenhouses in the Guanzhong area,summarizes the forms of failure of different structures,analyzes their failure mechanisms,proposes upgrading and transformation measures for the failed structures of solar greenhouses,and verifies them.The main content and conclusions are as follows:(1)Research on the failure mechanism of solar greenhouse walls in the Guanzhong area.The solar greenhouse classified according to the wall.Through a large number of investigations,it is concluded that the soil wall solar greenhouse has a serious failure phenomenon.The failure phenomenon of the soil wall is divided into three forms: uneven falling off of the wall surface,wall cracking deformation and wall instability sliding.The failure reason of the wall is found through tests,including water content test,direct shear test test and unconfined compression test.The test results show that the water content of the external and lower parts of the wall is relatively high.When the water content of the soil on the wall surface is less than 5%,it is easy to fall off.When the water content is high,the mechanical properties of the soil sample are different from those at the optimal water content.A load calculation was conducted on a typical greenhouse in the Guanzhong area,and the results were compared with the experimental results.The calculation results showed that the bottom of the greenhouse soil wall is the most stressed part,and there is a risk of damage to the wall when the moisture content is greater than 20%.Based on the finite element analysis method using ADINA software,the natural and working states of the back wall of the greenhouse were simulated.It is believed that the stress on the back wall of the greenhouse mainly comes from its own self weight stress,and the maximum stress position is consistent with the calculation results.(2)Research on the failure mechanism of the framework of solar greenhouses in the Guanzhong area.Classify solar greenhouses according to their skeletons,summarize the failure phenomena of solar greenhouses in the Guanzhong area into three forms: skeleton corrosion,skeleton fracture,and skeleton instability,and analyze the possible causes of skeleton failure.Using ADINA software to simulate the working state of the skeleton under the most unfavorable load,it was found that the maximum displacement of the skeleton occurred in the middle of the front roof section,and the maximum stress position was at the supports at both ends.Comparing and simulating the truss structure with the circular tube structure,the results show that the circular tube structure is subjected to greater shear force and has poorer stability.(3)Propose measures for upgrading and transforming the walls and framework of solar greenhouses in the Guanzhong area.Exploring the upgrading and renovation methods for walls and frameworks that have failed,and starting from changing the shape of the wall and optimizing the connection between the framework and the back wall,this study proposes upgrading and renovation measures to control the wall thickness,soil slope angle,and inclined back wall angle between 1m～1.5m,55 °～60 °,and 80 °～85 °,respectively.It proposes optimizing the load transfer path by adding rods and setting beams,Upgrade measures to reduce eccentric compression on the wall by changing the connection position between the skeleton and the wall.It is proposed to reduce the angle of the skeleton web member to enhance the overall strength and stability of the skeleton,and to set support rods at the corners and supports of the skeleton to reduce local excessive stress.The upgrading measures of setting support rods at the front roof section to enhance the stability of the skeleton provide reference and suggestions for the upgrading and renovation of solar greenhouses in the Guanzhong area.