Study On Parameter Identification Of Construction Control Based On Experimental Modal For Continuous Rigid Frame Bridge

In construction process continuous rigid frame bridge is affected by many factors,all kinds of parameters will appear different degree of deviation,caused the final state deviates from the design goal.Therefore,construction monitoring have great significance for long-span prestressed concrete continuous rigid frame bridge.Achieve the design expectations in the construction process and bridge state.Parameter identification as an important part of monitoring,by analyzing the structural state error,the use of various types of mathematics algorithm to identify the construction process of the design parameters of the true value.Based on the study of existing construction monitoring parameters identification,this paper studies the parameter identification of continuous rigid frame bridge is carried out from two aspects of static test and modal test.Main tasks are as follows:By reviewing relevant literature,summarized the many influence factors of construction monitoring and the principle of least square method and neural network.According to the characteristics of the project and construction schedule of SanChaGou Bridge,the calculation model of bridge construction monitoring have established,which provide basic data for the correction of parameter identification.Many methods of parameter identification and its essence is to seek the optimal solution of static and dynamic response error of structural state.Before the quantitative parameter identification,parameters sensitivity should be analyzed qualitatively,determined the deflection and stress of the main design parameters,which will provide the basis for the selection of parameter identification.Based on static and modal test for short,medium and long cantilever states of the SanChaGou Bridge,the least squares method is used to quantitative identify the main design parameters.According to the results,the theoretical model is revised,and the theoretical and measured control results of the bridge been compared and analyzed.The wireless acceleration sensor on the fork in the ditch bridge short,medium and long three cantilever state tested ambient excitation mode test.Using the least square method and neural network algorithm,the test result is used to calculate the self-weight and stiffness based on model,the comparison of two algorithms.Based on the free beam and cantilever beam,the analytic expressions of the frequency and mode vibration of the free end rigid cantilever beam are derived,according to the analytic expression,a kind of equal section free end rigid mass cantilever beam is selected as an example,and the numerical solution of the frequency and vibration mode with span is obtained.