The Safety Evaluation Of Reinforced Concrete Frame Structure After Earthquake

It is very important to evaluate the structural safety in disaster area to determine theextent of the damage for the post-earthquake relief and post-earthquake reinforcement.Rescuer can take corresponding measures to rescue the trapped people at the same time,as far as possible to ensure their own safety.According to the results of the assessment.We can take the corresponding treatment plan according to the degree of structural damage,for the structure with serious damage,evacuate the people inside in time to avoid the occurrence of secondary disasters;For the weak components or weak layers of the structure,we can take the corresponding measures to make the best use of people and material.The traditional structural safety assessment after earthquake is mainly focused on the qualitative analysis of the damage of structures or components,by professional staff to observe,add up,weight and calculate the damage of structure,which is fast,easy to operate,but it lacks a rigorous theory,and the statistical results depend on the subjective identification of the statistical personnel on the spot,therefore it will hav a greater randomness,especially the situation of disaster area is complex,if the entrance was blocked,observers will can not get the information of the damage of components inside.Therefore,it is very important to select a kind of security evaluation scheme which is universal and has theoretical basis.The main work of this paper is as follows:(1)In this paper,the damage model based on damage index is introduced in detail.Compared with the Single-parameter damage model,the damage information of the Wang Guangyuan-Lv Dagang damage model matches the definition of Two-parameter damage model,has a simple computational formula,and solves the problem that the Upper and lower bounds does not converge in most model damage models.Therefore,this model is used to calculate the damage index of structural components.(2)The numerical model of reinforced concrete column is established,the low cycle analysis is carried out,and the hysteretic curve is drawn based on the open source finite element program Open SEES,which is compared with the experimental data to verify the correctness of numerical calculation with Open SEES.(3)The Wang Guangyuan-Lv Dagang damage model is used in this paper to determine the damage index of each component of the structure,and find out the weak component andweak layer of the structurewith a numerical model of 6 story reinforced concrete frame structure is established and the nonlinear time history analysis is carried out.The corresponding relation between damage grade,damage index and macroscopic damage of reinforced concrete beams and columns is summarized,so that the method of structural safety assessment can be applied to the rapid evaluation of post earthquake structures.(4)Calculate the damage index of the layer and structure with the weighted combination method.By this method We can conclude the damage index of the structure in three levels:the component,the structure and the whole structure.It can be used to find out the weak component and the weak layer of the structure under the earthquake,and provide guidance for the emergency rescue and the reinforcement of the structure after the earthquake very intuitively.(5)The indexes of ground motion have great influence on the response of structures.In this paper,the influence of the hypocentral distance on the overall damage of the structure is preliminarily determined,which can provide some guidance for the prediction of the structural damage and the rechecking for evaluation of the structural damage.