Prediction of the influence of the proposed Beijing metro line 16 on a precise instrument of Peking University
GENG Wanli;LIU Dunyu;CAI Yongen;ZHANG Qiong;LEI Jun;School of Earth and Space Sciences,Peking University;
In this paper,using observed accelerations from the rails of Beijing metro as vibration sources,we build a three-dimensional metro model containing floating slab-tunnel-formation system to study the influence of the surface vibration caused by the proposed Beijing subway line 16 on a high precision electron microscope,Tecnai F30( hereinafter referred to as the F30),of Peking University,which is about 200 m from the rail alignment. To do this,firstly,we simulate the vibration of Beijing metro line 4 passing through the east gate of Peking University station and its influence on the F30,and then the acceleration measurements of the Shanghai metro line 7 is selected as vibration source for the proposed Beijing subway line 16 model in consideration of that they have the same orbit radius of rail and the same vehicle model. The results show that: the simulation results of the metro line 4 show that at 140 m observation point,no matter single or double operation,there are part of the spectrum( 3 ~ 5 Hz) to get into the F30 non-working range,and for the 16 line at the distance of 200 m,there is only part of the spectrum getting into the abnormal-working range: the horizontal acceleration at 0 ~ 0. 8 Hz and 4 ~ 6 Hz and the vertical acceleration at 5 ~ 6 Hz are in the abnormal-working range of the F30,respectively.