Lingzikou Tunnel is located at 30 km north-east of Shaotong city in Yunnan Province, the adjoining rock stability analysis and evaluation. Engineering geological conditions in Lingzikou Tunnel are complicate. The rocks are mainly sandstone, dolomite, marl and calcareous mudstone. Three small alluvium landslide in the entrance of Lingzikou Tunnel belong to unfavorable geotechnical conditions. The ratios of all rock strength stress are more than 6, so that plastic, shear and flexure deformations would be seld...