Chinanews, Xining, May 14 - This year, 4 earthquakes above magnitude 5 on the Richter Scale have hit the Qinghai-Tibet Plateau, including a magnitude 6.1 one and a magnitude 5.6 one in the early May. However, they have posed no threat to the busy Qinghai-Tibet Railway, which is designed and built to survive even tougher earthquakes.Two earthquakes happened in Qinghai, and the rest two in Tibet, all in uninhabited zones. Thus no severe damages were caused."The special geological structure of the Qinghai-Tibet Plateau is the main reason for frequent earthquakes here. Statistics show that Tibet ranks No.2 in the incidences of earthquakes in China, while Qinghai ranks No.4," said Chen Yuhua, the director of the Forecasting Center of Qinghai Provincial Seismological Bureau.The designers of the railway had taken the special conditions of the plateau into consideration in the very beginning of the project, and many anti-earthquake devices had been included."I was traveling aboard a train on the Qinghai-Tibet Railway during the last earthquake, and I didn't feel anything at all," said Li Shunping, the director of the Operation Department of Qinghai-Tibet Raiway Corp.