Overall Safety Analysis Of Steel Reinforced Concrete Piers Based On Principle Of Structural Reliability

The pier is an important part of the water discharge structure in the water conservancy project.In order to adapt to the construction of the large head and high-load water conservancy hub,the new pier structure of the profile steel in the tensile stress zone of the pier has shown superior performance,due to the current profile steel.The research on the structure of concrete piers is in the initial stage.The influence of the structural form of steel reinforced concrete structures on its overall safety performance is very little.Considering the important position of the piers in the water conservancy,in order to avoid A major safety accident occurred in the construction of steel reinforced concrete piers in actual projects.Mastering the real-time safety status of steel-reinforced concrete piers requires an effective method to judge the safety state of steel-reinforced concrete pier structures,and provide theoretical support and reference for the design and construction of steel-reinforced concrete piers.Combined with the theory of structural reliability,the ultimate bearing capacity and static water load of steel-reinforced concrete piers are used as random variables to establish the extreme function of the overall safety of steel-framed concrete piers.The JC method is used to calculate the structural reliability indicators reflecting structural safety,eventually,Overall Safety Analysis method of Steel Reinforced Concrete Piers is established.The main research contents of this paper are as follows:(1)On the finite element calculation platform ANSYS,a steel reinforced concrete pier model with the pier of YongNing Water Conservancy Project as the engineering background was created,and The ultimate bearing capacity of the steel reinforced concrete pier structure under symmetrical load conditions and asymmetric load conditions is calculated and the ultimate bearing capacity results are verified by The load-displacement curve(2)Using the probability design module on ANSYS software,The main factors affecting the ultimate load of steel reinforced concrete piers are randomly sampled and the input samples for solving the ultimate load of steel reinforced concrete piers are formed,and set the steel-concrete concrete pier model with different structural forms.And calculate their ultimate bearing capacity samples accordingly(3)the optimal distribution type of each ultimate bearing capacity sample is determined by probability paper method and distribution test method,and the statistical parameters of ultimate bearing capacity is determined by maximum likelihood estimation method.The calculation shows that the ultimate bearing capacity distribution of steel reinforced concrete piers Types are mainly normal distribution and lognormal distribution.(4)The iterative calculation program of JC method is written by MATLAB software.The ultimate bearing capacity and static water load of steel reinforced concrete pier are used as two random variables to establish the extreme function reflecting the safety of pier structure.The target structure index determined by the specification is the criterion,The structure Reliability indicator of steel reinforce concrete piers with different structural types is calculated.An analytical method for reflecting the structural safety of steel-reinforced concrete piers is established.(5)Computational research shows that under the two working conditions,The structural reliability index of steel-reinforced concrete piers is greater than the target reliability index required by the specification,and the safety performance meets the basic safety requirements of the specification.the change of the embedded length of the profiled steel has relatively little influence on the safety of the pier,and the number of profiled steel,the angle of the profiled steel,and the change of the layout of the transverse steel to the safety of the pier is relatively large.The overall safety of steel-reinforced concrete piers is linearly related to the number of embedded steels and the length of embedded steels,but not linearly with the angle of steel profiles.The optimal layout angle should be determined according to the actual project.In the case of the same amount of steel,the piers with single transverse steels at the legs are the safest.Moreover,the change of layout of transverse sections has relatively largest influence on the safety of the pier.