Seismic Response And Vulnerability Analysis Of Building Liquid Pipeline

With the rapid development of Chinese economy and the continuous improvement of modern building standards,the types and quantities of non structural components in buildings are increasing day by day.The casualties,economic losses and loss of building functions caused by the earthquake damage of non structural components have attracted the attention of domestic scholars and foreign scholars.As a basic non component to guarantee the building’s function,the building’s infusion pipeline undertakes the functions of fire fighting and water resources transportation.Previous earthquake damage shows that the damage of the pipeline system will greatly weaken the functionality of the buildings.At present,there are few studies data about the seismic performance of pipeline system in China,and it is also lack of studies about the interaction between the main steucture and the pipeline.In this paper,considering the influence of the seismic response to each floor of the main structure on the secondary input of the pipeline,a series of elastic-plastic time history analysis is carried out on the pipeline system and the main structure model,and the influencing factors of the seismic response of the pipeline system are studied.Taking a hostipal project as an example,the vulnerability analysis of the main structure and pipeline system is carried out.The main contents are as follows:(1)Building pipeline integrated coupling model and pipeline multi-point excitation analysis model are established respectively,and the elastic-plastic time history analysis of the two models is carried out,andthe maximum displacement error of the two models is5.8%,and the results are in good agreement.It is considered that the seismic response analysis of the pipeline can separate the pipeline from the structure and take the floor response as the dynamic input of the pipeline for separate analysis.The results show that the displacement response of the pipeline caused by the inertial force is negligible compared with that of the floor.It can be considered that the displacement response of the pipeline to the ground is mainly affected by each floor of the main structure.(2)Based on the elastoplastic time history analysis of a 7-story frame structure,the amplification coefficient of the floor acceleration of the main structure under the action of earthquake is obtained.It is found that the amplification effect of the floor acceleration of the structure is related to the height of the floor and the intensity of the ground motion.Generally,the peak of the acceleration increases with the increase of the floor.Under the action of small earthquake,because the main structure is still in the elastic stage,the floor amplification coefficient of the main structure is lower than that of the moderate earthquake.It is larger under the action of large earthquake.The floor response spectrum is established,and the equivalent lateral force method and the floor response spectrum method are used to calculate the seismic action of the seismic support of the pipeline.The comparison of the two methods shows that the seismic action quantitative value of the support calculated by the equivalent lateral force method is less than that calculated by the floor response spectrum method,and the floor response spectrum method is safer for the seismic design of the seismic support.(3)The influence factors of seismic response of pipeline are analyzed.The main structure type,pipe diameter and the influence of flexible connection on seismic response of opposite pipe are studied respectively.The results show that the internal force of pipeline in frame shear wall structure with larger lateral stiffness is smaller than that in frame structure;the calculation results of pipeline with different pipe diameter in frame structure are analyzed,and it is found that the internal force of pipeline is smaller with the pipe diameter.The internal force of the pipeline after setting the flexible support is greatly reduced.When the flexible support is set at the connection of the pipeline and the structure,the support stiffness is within the range of 2×10~6N/m-2×10~7N/m,which has a better effect on the reduction of the internal force of the pipeline.(4)Taking an 8-story hospital building as an example,taking the peak ground acceleration as the seismic intensity index and the maximum displacement angle between floors as the engineering demand parameter,the vulnerability analysis of the main structure based on the incremental dynamic analysis is carried out.The failure probability of the structure under different performance levels is obtained,and the vulnerability curve is drawn.The probability of a certain damage state of the structure under different earthquake intensity is calculated,and the results show that the structure meets the seismic design standard of our country.The vulnerability of the vertical riser of the building is carried out with the peak ground acceleration as the earthquake intensity index and the maximum displacement angle between floors as the engineering demand parameter.Through the analysis,the exceeding probability of the pipeline in the state of leakage and failure damage is obtained;the overall model of building seismic support is established,the peak acceleration of ground acceleration is taken as the index of ground motion intensity,and the peak acceleration of each floor is taken as the engineering demand parameter.The vulnerability analysis of anti-seismic support is carried out and compared with the ordinary support,which shows that the seismic support can effectively improve the Seismic performance of pipeline system.