Abstract: This paper documents a case history of the Tong-Luochuan Tunnel construction in the Zhengzhou-Xi'an high speed passenger rail project. The construction aspects of the construction of a large cross section with shallow covered slope in the collapsible loess are introduced. These techniques include: Long pipe roof with guide wall and small diameter guide pipe grouting preshielding; Cross Diaphragm (CRD) method; Observation Method (construction is guided with the observed information). The construction practice indicated that these construction techniques effectively reduced the deformation during the construction and prevented the tunnel collapsing accidents.

Key words: Long Pipe Roof, Small Diameter Guide Pipe Grouting, Cross Diaphragm (CRD) Method, Monitoring and Surveying