The Study On Railway Ecological Environment Evaluation Index

Zhengzhou-Xi'an Railway Passenger Special Line is 458.279 kilometers long totally and has 38 tunnels, 76703 meters long, most of which are loess tunnels. And Tong Luochuan tunnel, 3817meters long, is a typical large section collapsible loess tunnel of the line.There were many studies and reports about loess domestic and abroad these years and many loess tunnels were, constructed which gave us rich practical experiences. However, there is no large section tunnel up to 170 m~2, 15.20 meters wide and 13.18 meters high. Due to cognition limitation and affect of design theory, the ground settlement, serious crack and vault settlement appear during large section loess tunnel construction which not only affect ground environment esp. the section with highway or railway underside, but also affect construction safety and progress.This paper mainly studies on project general situation, design parameter, construction measures, deformation data simulating calculation, deformation rule during construction and controlling measures of large section loess tunnel such as Tong Luochuan tunnel of Zhengzhou-Xi'an Railway PDL, and puts forward some questions and proposals based on present construction.