Study on Ground Surface Settlement of Beijing Metro Line 5

309 ground surface settlement measuring points were collected based on the 10 mining sections of Beijing metro line 5. According to the method of the selection of the data, 288 effective points were picked out for statistics analysis. The average settlement is 32.4mm, 45% of the points' settlement is less than 30mm, 69% of the points' settlement is less than 40mm, the number of the points whose settlement is less than 30mm doesn't reach 50%, and it is means that the control standard of 30mm for ground surface settlement used now is not available and need correction. The curve of settlement measuring points' ratio exists inflection point in 40mm which means settlement probability density reaches peak in 40mm. Based on measuring data and whole process control method, new settlement control standard for mining section of Beijing metro line is put forward. The critical settlement for ground surface is made to be 40mm, the prewarning settlement is made to be 24mm, and the alarm settlement is made to be 32mm.