Dynamic Response Analysis Of Ultra-high Earth-rock Dam Under Explosion Load

In recent years,a large number of large scale water conservancy projects,especially ultra-high earth-rock dams,have been constructed in China.The number and height of earth-rock dams are increasing in the reason of their strong adaptability to geology and topography and relatively low cost.Once dam breaks occur,especially those of ultra-high earth-rock dams,it will even cause continuous dam breaks of cascade reservoirs,which will cause huge disasters to the safety of people’s lives and property downstream.The negative social impact is incalculable.Regardless of the re-emergence of anti-globalization,the occurrence of terrorist attacks,or the disassembly of old dams due to the expiration of their service life and the reduction of their applicability,with the development of the times,the explosion response analysis of reservoir dams has attracted more and more attention.However,in the general safety protection of earth-rock dams about seismic,explosion,flood and other extreme cases of design and research,it has been mainly earthquake and flood,but less research on explosion.Therefore,it is of great practical significance to analyze the dynamic response of earth-rock dams under explosion load and to study their explosive resistance and mechanism of explosive damage.Based on the development status of earth-rock dam and the basic theory and calculation method of display dynamics,this paper takes the gravel earth core rockfill dam of Changheba Hydropower Station as the research object,uses Mechanical module of Ansys-Workbench to carry out static analysis,and transfers static analysis data to Autodyn explicit dynamic analysis module to carry out dynamic analysis of earth-rock dam under explosive load.Deformation and stress are analyzed,and the failure mechanism and process are studied.Its main contents are as follows:(1)The impact effect of explosion load on earth-rock dam is analyzed in three categories.The CJ theory of detonation wave is elaborated.The non-linear explicit finite element analysis software Autodyn and the commonly used dynamic calculationmethods are compared and analyzed.(2)The three-dimensional solid model of earth-rock dam is established by using Mechanical module of Ansys-Workbench.The static analysis of earth-rock dam is carried out under two conditions of completion and storage periods.The stress and displacement of the dam are analyzed systematically.The comparison with the static analysis results of the same dam body in the literature verifies the applicability and rationality of the model in this paper.(3)Based on advanced treatment and static analysis in Mechanical,the three-dimensional finite element solid model of Changheba ultra-high earth-rock dam-explosion-air is established by using Autodyn module.The dynamic response of earth-rock dam under explosion load is simulated by CEL(Coupled Lagrange-Euler)method.The stress and displacement of earth-rock dam are analyzed as a whole,and the stress,velocity and position of typical observation points are also analyzed.Time-lapse analysis and calculation are used for studying the effect of the dam under TNT explosion load.Then the influence of explosive quantity and explosive location on dynamic response of earth-rock dam are analyzed.Based on the simulation of Changhe dam,some useful conclusions are obtained.The displacement,stress distribution and magnitude obtained by static analysis are in good agreement with other simulations.The regularity of explosion response and failure mechanism obtained by dynamic analysis is good.The analysis results will have guiding significance and practical significance for the safe operation and management of Changhe dam.And the anti-explosion and disaster reduction of similar dams have certain reference value.