Research On The Stability Of Expansive Rock Slope In The Nanning Basin

Expansive rock is a special type of soft rock, and it is of potential for shrinking and swelling which can be caused by the change of water content. Because the engineering characteristics are complex and varied, a lot of hazards of expansive rock slope occur frequently and cause hidden dangers for works construction and communications and transportation, and at the same time the cost of it's treatment is very expensive. Due to above causes, the engineering characteristics, the stability of slope and engineering measures of expansive mudstone in the Nanning basin are studied in the paper.1. The physical and mechanical properties and geologic features in the field of expansive mudstone in the Nanning basin are introduced. The swelling mechanism and engineering characteristics of this kind of expansive rock are discussed. In addition, the engineering classification of expansive rock in the Nanning basin is given.2. The characteristics of deformation and the type of destruction of expansive rock slope and the major factors to influence the stability of slope are generalized. The destruction mechanism and destruction mode of roadcut slope in expansive rock and the influences of groundwater on slope are analyzed systematically. Combine with the calculation of landslide thrust and the choice of strength parameters, the factors and problems which must be considered for calculating the stability of expansive rock slope are pointed out.3. The design rules, treatment countermeasures and engineering measures are put forward. The effects of adopting gentle slope, wide platform, strengthening the foot of slope and suitable protection on the surface of slope are introduced particularly with two engineering instances. At last, some important measures for ensuring stability of roadcut slope such as forbidding construction at rainy season, draining water away, keeping wet and preventing seepage, and constructing fast are presented.