Seismic Vulnerability And Functional Failure Probability Assessment Of Landing Communication Station

Communication system is one important lifeline system.After the earthquake,the extent to which the communication system in a region can work properly is directly related to whether the information in the disaster area can be transmitted to the outside world and whether the rescue work can be carried out smoothly and efficiently.Therefore,it is of great significance to evaluate and predict the seismic capability and the post earthquake functional status of a communication system in an area before the earthquake.In the past research on the seismic disaster prediction of communication systems,only the buildings of Mobile Switching Center(MSC)and Base Station Controller(BSC)were considered,the large numbers of Base Transceiver Stations(BTS)were ignored absolutely.This is not accurate.Communication system is a complex network and its functional state after an earthquake depends on every element in the system.Therefore,the research on seismic performance of various typical BTS is the basic component of the research on the seismic capability of communication systems.In this study,the usually used BTS now in China was investigated.The seismic vulnerability of various typical communication towers and various facilities in BTS were addressed.Finally,the functional state of BTS after the earthquake was evaluated by using the fault tree method.The main work of this thesis is:(1)The form of typical communication towers was summarized based on the survey data.The Pushover analysis and incremental dynamic analysis(IDA)were performed for the 50 m square tower,30 m square tower and 50 m single pipe tower.The damage index and various damage levels were defined.The seismic fragility curves of the said three types of communication towers were obtained.(2)The survey for BTS was carried out,the facilities that have great influence on functional state of BTS after an earthquake were identified.The Pushover analysis and incremental dynamic analysis(IDA)were performed for the color steel sandwich panel room,cabinet,wire rack and storage battery.The damage index and various damage levels were defined.The seismic fragility curves of these facilities were obtained.(3)Based on the fault tree method,a method for evaluating the failure probability of the whole communication base station after an earthquake is proposed.