Cause Analysis And Reinforced Structure Safety Of Cracks Of Concrete Piers Of Overflow Dam

It is a common phenomenon that the piers of dam of power plant appear cracks,especially in the northeast of China,few concrete gravity dams appear cracks during the construction period in pier,however,some cracks appear while many dams run many years,such as cross-cutting cracks,which have seriously affected the normal operation of power plant.The main reasons of cracking of pier are insufficient reinforcement,temperature stress overtaking and the static ice pressure overloading in front of the overflow dam.But this is only a qualitative analysis of the results,it is not clear which of the above reasons plays the leading role on pier cracking.Based on the 22nd section of overflow pier of Taipingshao power plant,this paper applies finite element method,the three-dimensional dam model has been established.Calculating the temperature field and thermal stress field of the concrete of piers,the impact factors of temperature load,ice pressure and other loads that are applied on the concrete of pier,stresses in the location of cracks are analyzed,as well as the main reasons for cracking of concrete piers. Combining with practical engineering,ANSYS software is used for calculation and static analysis of pier cracking.At the conclusion of previous work,the linear and non-linear analysis has been carried on to calculate the structure.The dam safety is estimated after reinforcement of the pier cracking.The following aspects are studied:(1) Establishing a proper finite element model,calculating the pier not cracking under the basic load combinations,the stress distributions of the location of cracking occurrence are obtained.Comparing the role of loading on the structure,the cause of pier cracking is studied.(2) Calculating the structure of pier of no-crack and reinforced pier after cracking,the result for security is analyzed to understand the impact of the ice pressure and temperature loads on the pier after the reinforcement of pier cracks.(3) A non-linear finite element model has been carded on to analyze the pier cracking,for further analysis of the reasons the influence of reinforced concrete cracking and rebar are considered,which is proofed of the reliability of linear calculations.In this paper,the pier of vertical cracking has been simulated,the numerical analysis of results have a certain reference value for similar projects.