Analysis Of Lvquan Masonry Arch Dam Upstream Thickness Strengthening Based On The Finite Element Equivalent Stress Method

Masonry arch dam as a kind of easy to use local material dam is occupied large proportion especially in small and medium-sized stone masonry dam construction in our country.As time goes on,some of the masonry arch dams have been identified as three types of dam which must be danger-eliminated and reinforced after years of operation.In addition to the intuitive observation effect,the analysis of the reinforcement effect is given by the calculation with the finite element model in this paper,and it also can offer theory and data support to this project.This paper studies the basic principle of finite element analysis of the dam body temperature load and dam body weight,discusses the boundary condition of temperature calculation,introduces calculation programs sqtp.f and arch.f both written by professor guo-ming Liu,details principle of finite element and the finite element equivalent stress.By taking Lvquan masonry arch dam as a case study,the finite element calculation model is established,the results is analyzed in this paper based on the finite element equivalent stress method,and it can be used for safety assessment of arch dams according to the national arch dam design code.The main contents of the paper are as follows:(1)The interface in the dam foundation is setting by thin layer elements to separate the constraints of the internal force.In this paper the dam in the actual mechanical behavior under the working condition is simulated,considering the coupling effects of water pressure,silt pressure,temperature field and gravity field,by finite element method is calculated,then,the stress of the dam body is analyzed based on the equivalent stress method considering different combination conditions of water level,temperature rise,temperature drop,etc.,stress of the dam before and after upstream thickening reinforcement is analyzed and evaluated according to the national arch dam design code.(2)When taking temperature drop as the main load condition,the maximal displacements are appear in the left and right top of the arch,the phenomenon of dam body is sinking,the dam near the top of the crown cantilever is sinking larger.When taking temperature rise as the main load condition,the upper dam rises,maximum rising appears on the top of the crown cantilever,the remaining parts of the dam are sinking,that downstream near the crown cantilever of lower-middle part is sinking larger.(3)Except the temperature dropping conditions,the stress concentration appears on both sides of the roof arch abutment,the stresses of other parts of the dam by the thick reinforcement are less than before strengthening.Masonry arch dam's upstream thick reinforcement measures make the dam stress improved.Finite element equivalent stress analysis of Lvquan masonry arch dam which upstream is thickness strengthening,gives the theoretical data support and experience for similar reinforced masonry arch dam.The exploration is helpful to application of finite element simulation analysis.