Analysis Of Secondary Heightening Static And Dynamic Force Of Masonry Dam By ANSYS

Water resource is a kind of clean energy,compared with the thermal power resources and nuclear power resources,it is more environmental and economic.With the continuous development of hydropower resources in China in recent decades,fewer addresses are suitable for new dams.On the other hand,some of the last century built old reservoir because of siltation problems for a long time,it cannot meet the requirements of the original design.The development of society needs more and more water resources,and these old reservoir can't meet people's requirement of water supply,irrigation and so on.Therefore,heightening and consolidating these old dams is the trend of dam construction in the future.This article takes the elevation project of Xiaoyao reservoir as the research object,threedimensional model for once shaped and secondary heightening of the dam were built in software ANSYS respectively.At the same time,the two models are subjected to stress-strain analysis,overload calculation,the calculation of anti sliding stability of the combination surface of the new and old dam body and the base of the dam under the static force.Next,the Block Lanczos method is used for modal analysis,the characteristics,advantages and disadvantages of the stress-strain of the two models of once shaped and secondary heightening of the dam under static and dynamic action are compared and analyzed.The results show that:(1)In the static condition,the stress-strain distribution of once shaped and secondary heightening of the dam are similar,it is also in line with the basic law of gravity dam.Overall,the maximum stress value of the secondary heightening of the dam is slightly larger than that of once shaped,and the displacement extremum is slightly smaller.(2)For anti sliding stability calculation under various conditions,whether it is once shaped or secondary heightening model,the safety coefficient of the calculation is greater than standard requirements,which shows the two models of dam safety are safe and reliable.(3)In the overload calculation,once shaped overload coefficient of the dam is 1.8,and the two heightening overload coefficient of the dam is 1.7.On the other hand,the crack of once shaped of the dam is a direct formation of "U" shaped crack,and the secondary heightening of the dam is to generate the right dam body cracks,then generate the left crack,and finally form a "U" shaped crack.(4)Comparison and analysis of dynamic characteristics under the action of empty reservoir and full reservoir conditions,once shaped and secondary heightening various modes of main vibration direction is consistent,and the frequency of full reservoir is slightly less than the empty reservoir.On the other hand,the natural frequency of secondary heightening is slightly larger than once shaped,which means that the distribution of rigidity and mass of the dam body is very uniform at once shaped and secondary heightening,but secondary heightening dam is slightly better than the once shaped dam.This article takes the actual project as the research object,and its calculation and analysis results provide reference for the design and safety research of the same type of masonry dam heightening engineering.