Elasto-plastic Analysis Of Aseismic Effect Of High Earth-rockfill Dam With Nail Tied Panel

Earth-rockfill dam is widely used because of its excellent characteristics such as easy selection, simple structure, economy, simple structure and good seismic performance. With the constant progress of theory of soil mechanics and construction technology, earth-rockfill dam has become the mainstream dam type. The earth-rockfill dam is mainly constructed in the western region, The landform and geological condition in this areas is complex and earthquake there is frequent and strong. Therefore urgency and importance of the aseismic measures research of earth-rockfill dam is becoming more prominent. The earthquake disaster data of earth-rockfill dam and the research results indicate that upper part of the dam is failed firstly under earthquake action, the state of rockfill in this part is most unstable because of whiplash effect. Therefore, it is necessary to pay attention to stability of the rockfill in this part,and take some seismic-resistant measures. Reinforcement technology is a very common and important retaining method in geotechnical engineering field. By taking reasonable reinforcement measures, not only the strength of the structures can be significantly improved, but also the used amount of engineering materials can be reduced, and this technology is conducive to safe construction, nail tied panel is one of these reinforcement measure, nail tied panel has been applied to the engineering design of earth-rockfill dams since it is proposed, such as Jilintai CFRD has been bulit and Lianghekou core rockfill dam is to be built, but engineering analogy is mainly daopted in these engineering, the corresponding analysis method is absent.The elasto-plastic finite element method is used to analyze the concrete face rockfill dam with150meters height level, no reinforcement measure and with nail tied panel is considered, the seismic performance of dam with nail tied panel is analyzed by deformation, major and minor principal stress, acceleration response, deflection and stress of face slab, shear strain of the rockfill of dam crest area, and seismic deformation of dam in this paper. The aim is to provide some numerical basis for the actual project. The work of this paper is as follows:(1) Generalized plastic model was improved by considering pressure dependency and hysteretic characteristics of rockifll materials.(2) The elasto-plastic finite element method is used to analyze the concrete face rockfill dam with150meters height level, to determine the reinforced range of dam by the analysis of shear strain and seismic deformation of dam. (3) By the simulation of dam with nail tied panel at0.5g peak acceleration earthquake, the changes of deformation, major and minor principal stress, acceleration response, deflection and stress of face slab, shear strain, and seismic deformation are researched to analyze the reinforcement effect of nail tied panel.(4) Based on the basic working condition, calculations of different earthquake intensity and different seismic wave in same intensity are developed to analyze the contribution of the dam stability with nail tied panel reinforcement measure.(5) Analysis is developed to analyze the reinforcement effect of nail tied panel with different reinforcement diameter, reinforcement space, reinforcement length, and face plate thickness.