Abstract：Due to the trend of road paralleling to the axis of the folds，cataclinal slopes are abundant in Hurong Highway in Hubei Province. Of all these cataclinal slopes，the moderate-dip cataclinal hardrock slopes with the bedding plane dip angles ranging between 20° to 60° account for 30 percent，so the stability and treatment are very important to highway construction. Aiming at these problems，this paper presents the character of landform and engineering geology of these types of slopes，and the deformation characterization and sliding process are also analyzed by means of deformation monitoring. Based on the works，the failure mechanism of this type of slope is studied. The result indicates that the penetrative discontinuities have expanded intensely because of weathering，corrosion，tectonic effect and gravity for a long time，and are filled with mud in a certain depth，and thus its shear strength reduces，which is the dominate factor leading to sliding of the moderate-dip cataclinal slopes of hardrock. The conclusion may be useful for assessment of stability and treatment of Hurong Highway and similar engineering.
