| At present, worldwide dam construction is still in development stage, about a number of150m-300m high dam has been built or are under construction. In times of peace, they are often designed and built to store water for hydroelectric power, drinking and irrigation in adjacent areas, to add water recreation spaces, to create waterway for the short-distance transport of people and goods across deep canyons in mountainous regions, and to regulate the river during a flood event. On the other hand, the breaching and an accidental damage of a dam can lead to a catastrophic flood event, displace millions of people and environmental pollution. And in the future, war tactics will include more long-range and precision attacks than in the past. Dams are also vulnerable targets to man-made explosion events, particularly with the advent of advanced long-range and precision missile technologies. Therefore, it has important scientific significances and high practical engineering application values to study damages prediction and protection decision-making of the concrete gravity dam by the action of far-field deep-water explosion.This paper presents the model test investigation of the concrete gravity dam structure by the action of an underwater shock wave, and protection scheme and emergency decision-making system’s frame was proposed.First of all, the risk of the concrete dam by the action of long-range deep-water explosion was estimated. In this paper the pressure of shock wave acting on the dam is calculated using a common used empiric formula. On the supposition of elasticity, the stress-strain and displacements is simulated with ANSYS software with different reservoir level. In the end of this part a quantitative estimated on the movement of fractured dam.Second, the feasibility of the model test and test theories were analyzed. To study the effect of a strong underwater shock wave on a concrete dam, in model test mechanical impact tests have been successfully implemented using multiple hammers to mimic underwater shock wave effects on concrete dams. A new device was deployed for a direct measurement of the impact force at the upstream face of dams. Dynamic analysis according to a case was conducted, by calculating the results verify the effectiveness device for a direct measurement of the impact force. Two kinds of contact condition between dam and base such as weak contact and anchoring contact are selected to carry out destructive tests of concrete gravity model dam under impact loading, compared with base-dam contact condition to dam damage influence. Although the damage similarity of the model and prototype is not verified, this method may be used to approximately forecast the damage of concrete dam and offer evidence to define a protection project.Then, to focus on the key engineering problem of process control of dynamic catastrophe of high dams, studied on the property of the flexible polyurethane foam as a material to protect the concrete gravity dam acting by strong underwater shock wave. The first, the main mechanical parameters of flexible polyurethane foam were measured. Second, two kind comparison tests(target:rigid wall and dam) were completed to examine the effect of flexible polyurethane foam layer on protection of structures from action by shock wave. Finally, the design scheme for thickness of the flexible polyurethane foam protection layer of the concrete dam in non-contact underwater explosion was proposed.Finally, the dam risk management decision support system under the deep water nuclear explosion condition is a complex, large-scale system. In this paper the overall structure of the system framework was designed. The idea of the risk, the vulnerability computing model of the dam was designed. And spectrum of structural damage of the concrete dam construction method was proposed. A multi-attribute utility theory was used to design the decision-making model in the early stage. System will provide to an emergency decision-making services to decision makers. |
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