Study On The Response Characteristics Of Steel Gate Structure Under The Impact Of Water Flow And Underwater Explosion Load

In recent years,with the continuous enhancement of China's comprehensive national strength and the continuous development of the national economy,water conservancy projects have become an important infrastructure that benefits the country and the people.The scale of their construction has been increasing,and the conditions of use have become increasingly harsh.An important structure in water resources utilization engineering,whose structural safety is the basis for ensuring the normal operation of water conservancy projects.This paper combines the design of plane fixed wheel steel gates commonly used in water conservancy projects such as reservoirs and sluices in northern China.The structural safety of a typical hydraulic steel gate in northern China is studied.During the operation of the gate,in addition to the conventional hydrostatic pressure load,it will also be subjected to some extreme loads.This article mainly considers two aspects of load conditions:on the one hand,the gate will be subjected to the load of water scouring during flood discharge.Under the effect of the current scour,the gate structure is liable to instability,resulting in permanent plastic damage;on the other hand,it is considered that the gate will be subject to mines or underwater blasts during underwater explosion and blasting projects or when wars and terrorist attacks occur.Attacks with other underwater weapons,such as explosives,are subject to underwater explosion loads.Once attacked by underwater explosions,it will cause fatal damage to the gate structure,causing huge damage to the downstream engineering of water conservancy facilities and the safety of people 's lives and property.loss.Therefore,this paper mainly studies the calculation methods of the two main gate failure loads of water scour and underwater non-contact explosion,and gives numerical calculation results.Plane steel gates(this paper adopts down-hole type plane fixed wheel steel gates)as one of the most widely used gate types in hydraulic engineering nowadays,due to the complex working environment of its structure,it poses a hidden danger to structural safety.In the process of opening and closing the gate,it will cause difficulty in opening and closing,cavitation or vibration.In severe cases,the gate may be damaged.In this paper,the large-scale nonlinear finite element software ANSYS is used to model the gate,and the numerical simulation analysis of the gate structure is carried out.The DTH steel gate with submerged water jump after the gate is taken as the research object.The analysis and comparison of the response under the load provides a theoretical basis for the selection of the structure of the bottom edge of the gate,which has important engineering significance.The bottom edge structure of different types of gates are analyzed.The finite element analysis software ANSYS calculates and analyzes down-hole flat fixed-wheel steel gates.The types of gates discussed in this article are divided into two types:First,the bottom edge angle is 180 °.The model is then optimized by using a 45 ° upstream inclination angle and a 30° downstream inclination angle at the bottom edge of the gate.The results show that the optimized model with an upstream inclination angle of 45 ° and a downstream inclination angle of 30° at the bottom edge of the gate is beneficial to the opening and closing of the gate,prolongs the gate life,and is more suitable for application in practice.At present,the number of underwater blasting projects such as the removal of cofferdams and the excavation of underwater foundations is constantly increasing.The underwater explosion load will affect the safety of the gate structure,and the structural safety of the gate under the effect of the underwater explosion load needs to be studied.Firstly,the calculation method of underwater explosion load considering the impact of shock wave,bubble pulsation and jet is given.Then,based on the fluid-solid coupling calculation method,a typical gate structure is designed under 6 different underwater explosion conditions,ie 6 different impact Under the factors,numerical simulations were carried out.Under different working conditions,the gates produced different forms of elastic or plastic deformation,but none of them had large plastic deformation.According to the research in this paper,it is recommended that the Reasonably set the working conditions,and choose the working conditions with long blast distance and small impact factor,otherwise it will affect the safety of the hydraulic gate structure.