Abstract: Geohazards, such as, landslides, have plagued the urban development of Chenzhou City for years. Most of the potentially unstable slopes usually contain coal layers. Soil layers that containing coal lenses have the characteristics of uneven stiffness and compressibility; weak connections between the soil and coal layers; poorly structured; fast weathering after exposed in the ambient environment and fast slaking when adding water; extremely variable engineering properties and prone to significantly reducing the strength when their structure are disturbed. Project experience indicated that the conventional design and construction measures in mitigating the slope related geohazards by applying the current code are not completely satisfactory.  This paper presents a case history of the stability evaluation of a typical high cut slope with coal lenses in Chenzhou City. The progressive failure of a slope is three dimensional numerically investigated by using FLAC3D. The correlations among various construction sequences and the various degrees of stability are investigated. Mitigation measures for the landslides are proposed. The results indicate that the stability of the potential landslide area was improved.

Key words: Coal Strata, Slope Stability, Chenzhou Area