P-wave-based Prediction Of Three Stage Disposal Ground Motion Threshold For High-speed Railway

Earthquake is a disastrous hazard regarding the safety and stability of high speed railway,though the probability of its occurrence is relatively small.In recent years the railway earthquake emergency disposal has developed,which is one of the effective means to reduce the earthquake disasters in high-speed railway.China is an earthquake-prone country,and the high-speed railway develops rapidly.Therefore,it is urgent to build a railway earthquake emergency disposal system.To meet the requirements of timeliness and effectiveness of the railway earthquake emergency disposal,it is significant to solve the technical problems of lacking disposing time and alarm accuracy in the method.Aimed at acquiring the emergency disposal PGA timely and accurately,the study focuses on threshold-based earthquake early warning for high-speed railway,with Japan's K-net strong motion observation data,and the linear relationship between the warning parameters of P band and earthquake magnitude,emergency disposal PGA.The research contents are summarized as follows:1.The linear statistical relationship of characteristic period ?_c and magnitude,the warning parameters of P band and the emergency disposal PGA(0.05-5Hz filtered horizontal acceleration records combined value)is established,using Japan's K-net strong motion observation data.Based on linear regression analysis method,it is clearly that the displacement amplitude P_d and the square of the velocity integral IV2 are the warning parameters of P band which have a great linear relationship with the emergency disposal PGA.In view of the above research,the value of P_d and IV2 in P band threshold corresponding to the emergency disposal PGA values 40 gal,80gal,120 gal and ?_c values corresponding to magnitude 6 are transformed.2.This research studies the two-parameter emergency disposal PGA prediction method based on the displacement amplitude P_d and characteristic period ?_c,the square of the velocity integral IV2 and characteristic period ?_c,and defines the success disposal,success not disposal,omission alarm and false alarm of this method.Based on the Japanese K-net strong motion observation data,this paper shows statistical data of success disposal,success not disposal,mission alarm and false alarm rate of this method,and analyzes the reasons of mission alarm and false alarm.3 Based on the observation data of K-net strong earthquake in Kumamoto earthquake in Japan on April 14,2016,the validity and timeliness of the method are analyzed.