Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education Lanzhou University Lanzhou 730000 China;
Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education Lanzhou University Lanzhou 730000 China;
Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education Lanzhou University Lanzhou 730000 China;
Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education Lanzhou University Lanzhou 730000 China;
Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education Lanzhou University Lanzhou 730000 China;