Abstract:The proposed Chuanwen Expressway traverses the Songpan-Garzê fold belt and the West Qinling fold-fault belt on the eastern margin of the Qinghai-Tibet Plateau, and passes through the Maowen Fault Zone, Minjiang Fault Zone and other areas with intense neotectonic activities where strong earthquakes have occurred in history in the form of tunnel or bridge engineering. The tectonic background of this area is very complex with lofty mountains, deep river valleys, steep terrain and fragile ecological environment. The poor geological conditions are widely distributed with diverse types and large scales. The giant and large-scale gravitational geological phenomena are everywhere along the Minjiang River Valley, and the poor geological conditions such as landslides, rock piles, collapses and debris flows are distributed in groups, which have a very serious impact on linear engineering projects like expressways. Combined with the geological survey and special geological research conclusion of the Chuanwen Expressway, the characteristics of the main geological disasters in this area are analyzed, and the comprehensive geological route selection is studied. The route selection schemes for the Tongzhong section, the Manaoding to Shaba section and the Yanmen section of the line are compared and selected. The principles of geological route selection are expounded from three perspectives, and a set of comprehensive route selection strategies applicable to complex geological conditions is proposed.
