Searching For Critical Sliding Mode Of Arch Dam Abutment And Anti-sliding Sensitivity

The stability problem of arch dam abutment is an important link to analyze the safetyand stability of the arch dam.At present,scholars have proposed a variety of calculation methods for the anti-sliding stability of the arch dam abutment.The representative ones are the limit rigid body equilibrium method,finite element method,discrete element method and so on.These methods need to assume the bottom sliding surface of the dam abutment slider,think that the location and shape of the bottom sliding surface will not change with the seismic intensity,and ignore the influence of faults and fissure joint groups existing on the abutment rock mass on the stability of the abutment sliding.In view of the above problems,this paper considers the influence of rock mass structural plane,based on the seismic time history method,the genetic algorithm is used to search for the critical sliding surface of the anti-sliding of the arch dam abutment,and the change of the critical sliding surface of the abutment slider with the seismic intensity is analyzed.The anti-sliding stability of the abutment of the concrete arch dam has been studied on the sensitivity to shear strength parameters and ground motion.The main research contents of this article are as follows:(1)The calculation methods and basic principles of arch dam abutment anti-sliding stability and critical sliding surface mode search are reviewed,and the advantages and disadvantages of each method are compared.The basic principle of endurance time analysis method is elaborated in detail,the synthesis process of seismic time history curve is revealed,and three seismic time history curves are artificially synthesized.(2)According to the basic principle of genetic algorithm,considering the influence of rock mass structural plane,the calculation formula of anti-slip coefficient after the connection rate is added is derived.The improved anti-slip coefficient calculation formula is used as the objective function of the genetic algorithm,and a new genetic algorithm program is written.The program verification results show that the program in this paper has a good applicability for the search of the critical sliding mode of complex rock mass,and has accurate search results Features of high sex and good stability.(3)In the case of structural engineering,the genetic algorithm is used to search for the critical sliding surface of the concrete slider dam abutment based on the endurance time analysis method,and the most dangerous sliding surface under different seismic intensities isdetermined.Considering the situation where the position and shape of the critical sliding surface changes with the change of seismic intensity,the overall anti-slip coefficient curve of the dam abutment slider is obtained.Considering the randomness of the ground motion,the overall anti-slip coefficients under three seismic time-history curves are obtained.(4)Based on the concrete arch dam engineering example model and based on the endurance time analysis method,the anti-sliding stability performance of the arch(5)dam abutment and the shear strength parameters and the analysis of seismic motion sensitivity are studied.Evaluation method of anti-sliding stability of dam abutment.It is concluded that the anti-sliding stability of the dam abutment is the most sensitive to the cohesive force on the rock bridge.The friction coefficient on the structural surface has almost no effect on the anti-sliding stability of the dam abutment.,The anti-sliding stability of arch dam abutment is weak to ground motion.