Da Nang – Quang Ngai highway is one part of the North South Expressway with 139.52 km long, 24.5m wide. Tunnel is section of package 4 with station Km 22+500 – Km 23+000. Region tunnel located at Duy Son and Duy Chung commune, DuyXuyen district, Quang Nam province. Tunnel was designed to go through the small hill at altitude of about 120m above sea level. Bedrock is a sedimentary rock (alternation of sandstone and conglomerate).
Authors have detected incorrect at geotechnical investigation report and in situ analysis of intact rock. In situ intact rock have 2 fault system with grade V, location of faults in region South portal of including tunnel North and South. Intact sandstone location in left side of South portal of tunnel north has 3 faults system and bedding system. The bedding system has direction angle 150- 200, fault system perpendicular with bedding system have direction angle 75–80o; fault system overlap with face of rock slope have direction angle perpendicular with axis tunnel.
Application discontinuity model and failure criterion for anisotropic rock, analysis stability rock slope at left bank of south portal of North tunnel – Da Nang – Quang Ngai expressway.
Da Nang – Quang Ngai highway is one part of the North South Expressway with 139.52 km long, 24.5m wide. Tunnel is section of package 4 with station Km 22+500 – Km 23+000. Region tunnel located at Duy Son and Duy Chung commune, DuyXuyen district, Quang Nam province.
Tunnel was designed to go through the small hill at altitude of about 120m above sea level. Bedrock is a sedimentary rock (alternation of sandstone and conglomerate). Line of strike of the terrain is Northeast – southwest with strike angle about 600 from the North, bedding dipping 30° to the Northwest.
