Research On Dynamic Damage And Protective Measures Of Concrete Dam Under Explosive Load And Earthquake

As an important clean energy,hydropower plays a very important role in developing an energy-saving and environmentally-friendly green economy.More than 80%of China's hydropower resources are concentrated in many high-altitude seismic regions in the west,facing serious anti-terrorism and earthquake-resistant situations,which have brought many difficulties to the development of hydropower resources.Under the sudden extreme loads such as explosions and ground vibrations caused by terrorist attacks or wars,once a serious damage has occurred,the dam will cause serious secondary disasters to the downstream areas,seriously threatening the lives and property of the downstream people.For high concrete dams,the extreme loads that cause damage to the dam include explosive loads and strong ground motion loads.This paper is devoted to study the dynamic response and failure modes of concrete dams under blast loading and seismic loading,and proposes countermeasures to enhance the dam's ability to resist extreme loads.The main work is as follows:(1)In this paper,the stamping conduction effect of explosion shock wave in water explosion and air explosion are analyzed,pointing out that the impact pressure in water is more harmful to the structure.Concrete damage model,brittle fracture model,HJC model and RHT model are compared,which can simulate dynamic characteristics of concrete.The applicability of the RHT model to the anti-explosion performance of simulated concrete was verified by comparing the numerical simulation results with the anti-explosion test results of reinforced concrete slabs.The effect of spillway tunnel,different detonation positions,different detonation depths,different detonation distances and different dam front water levels on the anti-explosion performance of concrete gravity dam are discussed.According to the damage grade of concrete gravity dam,the detonation distance and detonation depth are comprehensively considered under blast loading.The damage prediction curve of concrete gravity dam with influencing factors such as the water level in front of the dam is studied.The anti-explosion protection performance of foam concrete to high concrete gravity dam is researched.(2)According to the law of explosion similarity and ALE fluid-solid coupling algorithm,the full coupling model of dam-foundation-water-air-explosive of concrete high arch dam is established.The dynamic response and failure of arch dams with different explosive equivalents,different detonating media,different detonation depths,different detonation distances,different horizontal initiation position and different water levels in front of the dam are discussed.Based on the studying of properties of the foamed aluminum materials,the anti-explosion properties of aluminum foam on concrete high arch dams were analyzed and calculated.(3)The realization of the viscoelastic artificial boundary wave input method is studied.The concrete arch dam model with transverse joint is established.Based on the concrete plastic damage model and considering the influence of the transverse joint of the dam,the damage under the action of high dam earthquake is studied.The dam body response of the arch dam under the design ground motion is calculated.The displacement of the dam crest and the arch crown beam,the transverse joint opening and dam body damage volume ratio are calculated when considering the expansion of the foundation and the pedestal as the seismic measures of the dam.The dynamic response and damage of the dam under 1.2 times,1.4 times,1.6 times,1.8 times and 2.0 times overload ground motion were studied.The displacement and transverse joint of the dam under different overload multiples were analyzed.Degree and the damage volume ratio of the concrete after zoning,according to the displacement curve,the transverse opening curve and the damage volume ratio curve,the protection effect of different design schemes on the seismic capacity of the dam is determined.