Study On Damage Characteristic And Antiknock Measures Of Concrete Gravity Dam Subjected To Underwater Contact Explosion

Since the reform and opening,many high dams have been constructed in domestic,such as the Three Gorges Dam,Xiluodu arch dam,etc.Dams are the important part of hydraulic structures and play a significant role in national security protection in the modern economic,social and political situation.With the development of modern war technology and weapons,dams have become the important objects for combating and fighting.In recent years,due to frequent attacks,it is critical to prevent the impact structure and research antiknock performance of dams.Therefore,it is of great practical significance to study the failure characteristics of hydraulic dams under explosive loading and antiknock measures.Gravity dams is one of the most common dam type in hydraulic dams.In this paper,nonoverflow section of dam and overflow dam section of one gravity dams are analyzed about dynamic responses and characteristics of damage and crack's distribution subjected to underwater contact explosion.Regarding these problems,the antiknock performance of dam is discussed when the aluminum foam is adopted as the antiknock material.The main work of the paper focuses on the following three aspects:(1)Firstly,the FEM model is established to simulate the contact explosion of nonoverflow section of concrete gravity dam under the conditions of both normal and empty reservoir based on the Lagrange algorithm.Considering the influence of high strain rate of concrete under the contact explosion,HJC constitutive model is adopted to simulate the damage characteristic and plastic deformation of the dam.Then,the dynamic response and damage characteristics of concrete gravity dam caused by contact explosion in both conditions are analyzed.(2)Secondly,the coupled Euler-Lagrange algorithm is employed to simulate the contact explosion of non-overflow section of concrete gravity dam.For non-overflow section of dam,the characteristics of damage cracks distribution and dynamic responses of the dam gravity subjected to explosion loading from different explosion positions are analyzed.For overflow section,the dynamic response and damage of overflow dam are compared when explosion shock waves are derived from different water level of reservoir.And the dynamic responses and failure modes of the overflow dam in underwater explosion with different explosion positions are investigated,respectively.(3)The aluminum foam is adopted as the antiknock material.The antiknock performance of dam is discussed under the contact explosion loading when the antiknock material is placed as a protective layer.Research results show that aluminum foam could effectively reduce the dynamic responses of the dam and narrow the scope of the cracks distribution are narrowed down.Aluminum foam has good antiknock performance when used in underwater contact explosion.