Three-dimensional Finite Element Analysis Of Large Surface Holes Of Masonry Arch Dams

In small and medium-sized water conservancy project,the shape of arch dam is relatively small,In some cases,we cannot choose appropriate position to construct spillway,which meeting with compact and complex geological condition.At this time,usually choose to open a big table in dam body hole to solve the problem of getting water and flooding,etc.This article apply ANSYS 3 d finite element software to establish finite element analysis model,researching the influence of setting big table hole in the arch dam body on dam stress and strain distribution.arch dam non-with large table hole,arch dam with wide-shallow hole big table,arch dam with narrow-deep hole big table,by comparing the stress and strain result of the above three kinds,to infer the effect of setting table hole in arch dam body on its stress and strain distribution.Combined with a project example,this paper research the main contents are as follows:1.To collect the shape parameter of arch dam,by using ansys 3 d finite element software to build dam body,dam foundation of 3 d model,based on the original model that not set the big table,setting wide-shallow big table hole,narrow-deep big table hole 3 d model by Boolean operation command.finally,make use of map grid partitioning and sweep grid partitioning synthetically,forming three complete meshed model.2.Imposing constraints and load on three models respectively,imposing omnidirectional constraints in the bottom of the model,imposing the normal constraint on the two sides of dam abutment,upstream and downstream dam abutment.need to applied loads are gravity,hydrostatic pressure,sediment pressure and temperature load.Bedrock is regarded as rigid body which not to be deformed.Make a static analysis of the three models under the two kinds of working conditions,normal storage level + temperature drop and check flood level+temperature rise.3.Analyze the result parameters of the three kinds of modle under two conditions,such as displacement of arch dam,arch stress,hoop stress,the first principal stress,the secondprincipal stress,the third principal stress and the equivalent stress of the maximum principal stress,study the distribution rule and value of stress and strain in dam body after setting a large table hole,compare wide-shallow big table hole with narrow-deep big table hole,find out the influence extent of their respective,prove the difference between the impact.4.In the 3 d fem analysis of arch dam,dam's foundation and the surrounding stress concentration phenomenon is obvious.in fact,the existed rock mass cranny will ease the stress concentration phenomenon,therefore,we make the calculation of maximum principal stress lineared to get the equivalent stress,think of the linearization as a stress criterion.