Study On Real State Simulation Of Concrete Dam And Safety Evaluation Method Of Combined Damming

This paper focuses on two problems in the field of hydraulic structure:the simulation of concrete dam's true state and the safety evaluation of combined damming.The new technology of combined damminghas been used in Xiangjiaba to build the dam.This new technology not only can accelerate the speed of the construction,butalso can save the cost of engineering construction.This is development and innovation of the dam construction technique,and has obtained significant economic and social benefits.Due to differences in thermal and mechanical propertiesof two kinds of concrete in the dam,the differences may affect the anti-sliding stability,but thepresent standard exist blankabout this issue,so there is an urgent need for suggestions on the safety evaluation method of combined damming.Based on current situation,this paper compares five different methods:two standards,direct strength reduction method and the strength reduction method after whole process of simulation,obtained the following conclusions:(1)the strength reduction after whole process simulation is optimal method for safety evaluation,and it can be more realisticthan the rest four evaluation methods;(2)during the process of approaching the dam'slimit state,the increase of concrete elastic modulus in the front area weakensthe anti-sliding stability of the dam;(3)using the MC strength criterion can simulate further full results;(4)the difference inlongitudinal joint behavior has little effect on the whole dam safety and state.Based on finite element method,the real behavior simulationhas been further developed and exhibitedbeyond traditional finite element method.Recent research results show that there are still some insufficienciesin the traditional method for realizing the real behavior of high arch and gravity dam.Based on this,the simulation analysis about the whole damming process has been made,with the followingconclusion:(1)the temperature rise can becalculatedusing the adiabatic temperature inversion formula,and the earlytemperature riseof can also be obtained;(2)there are thermodynamic differencesbetweenrolling and normal concrete about the late temperature rise;(3)Jinping arch dam late temperature rise is about 5-6?,and the elastic modulus of concrete and foundation is about 1.65 times biggerthan the design value,the concrete elastic modulus is about 36GPa;(4)the stress of zone close to the foundation surfacein high arch dam may be partially released due to partial separation of the foundation surface.