| Debris flow is one of the most serious geological disasters in the world.There have been several major debris flow disasters at home and abroad.Debris flow disasters have caused huge economic and property losses and deprived countless people of their lives.Therefore,how to effectively prevent debris flows Disasters have become a necessary research topic.?n the process of prevention and control of debris flow disasters,barrier dams play an important role as the main prevention and control method.Therefore,this article relies on the "National Natural Science Fund Project" to carry out relevant research on barrier dams.Based on the No.8 dam(reinforced concrete grid dam)of Sanyanyuda in Gansu Province,a grid dam structure with tube flange columns was proposed.The tube flange columns in this dam body are composed of front flange,web and rear flange welded components.The front and rear flanges are all steel tube concrete columns,and the webs are steel plates.The strong impact resistance o f steel tube concrete and steel plates is mainly used.To resist the impact of the block stones in the debris flow,pipe flange columns are used to replace the column members in the traditional barrier dam structure,which aims to improve the bearing capac ity while reducing the project cost.?n this paper,the finite element ANSYS/LS-DYNA numerical simulation method is used to study and analyze the tube flange single column and the tube flange grid dam structure,and the impact loading test of different typ es of tube flange columns is explored.The dynamic response and failure mode of the component and the entire dam structure under impact load.The details are as follows:(1)Perform finite element simulation and comparative analysis on three different types of concrete-filled steel tube columns with rectangular section,circular section and tube flange section,while ensuring the same cross-sectional area of the three column members.The analysis results show that: Bottom,the tube flange column has the smallest plastic strain,the largest impact force,and the smallest displacement and final residual internal energy.That is,in contrast,the tube flange concrete-filled steel tube column has stronger stability and impact resistance.(2)Based on the resea rch results of concrete-filled steel tube columns with tube flanges,the flanges and webs are improved.The improved tube flange columns are called special-shaped tube flange column ? and special-shaped tube flange column ?.The dynamic response of the fr ont and rear tube flange columns under impact load is compared.The results show that under the same impact load,the impact force of the profiled tube flange column ? is the smallest,the displacement is the largest,and the final residual internal energy is the smallest,while the impact force of the tube flange column is the largest,the displacement is the smallest,and the final residual internal energy is the largest.(3)Through the impact test of tube flange column,special-shaped tube flange column ? and special-shaped tube flange column ?,analyze their failure modes and compare them with the numerical simulation results.The results show that with the gradual increase of impact load,the failure modes of tube flange column,special-shaped tube flange column ? and special-shaped tube flange column ? can be roughly divided into four steps,namely:(a)Slight impact at the location Damage and deformation,(b)Slight buckling and deformation of the web,local depression and deformation at the impact position(c)Buckling and deformation of the web,overall bending of the tube flange column,and basic loss of working performance,(d)Bending and failure of the web,and the bottom fixed end Tear,completely lose the protective performance.?n addition,the comparison between the test results of the column member and the numerical simulation results is high and the error is small,which verifies the accuracy of the numerical simulation.(4)With the tube flange steel tube concrete column as the basic comp onent,based on the large No.8 dam body(reinforced concrete grid The full-scale model of the grid dam is designed to design the model size of the pipe flange column grid dam,and the finite element numerical simulation is used to analyze the response mode of the pipe flange column grid dam under impact load.The results show that: when impacting the column members of the dam structure,the dam has better cooperating performance,and the damage and deformation of the rear pipe flange columns are small;whe n impacting the beam members of the dam structure,the beam members ?t mainly resists more impact energy through local large deformation;that is,when the dam structure is impacted,only local component damage occurs,and the overall structure can continu e to play a role,indicating that the pipe flange column grid dam has a strong ?n addition,compared with the reinforced concrete grid dam,the dam body greatly shortens the construction period while reducing economic costs,and has higher practicability. |
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