The prevention and control of instability in slopes are important research aspects in geotechnical engineering. The ideas of slope stability analysis are changed with accumulating the practical experience. It is significant to analyze the slope stability and express the appropriate method to avoid the slope failure. The protection of any slope from sliding, side collapse or against weather conditions and erosion is properly illustrated.To meet the requirements of different construction conditions, there are varieties of slope classification.
(1) According to the cause of slope formation, it can be divided into two categories: natural slope and man-made slope. The natural slope is the naturally formed slope such as hillside, riverbank. The man-made slope is artificial slope like embankments, cuttings, excavations and landfills (Cha and Kim, 2011).
(2) Regarding properties of the soil, it can be classified into clayey, gravel, loess and rocky slopes.
(3) According to the section of the slope, there are vertical slopes, inclined slopes and stepped slope as shown in Figure 1.1. These three forms can form a composite slope, as shown in Figure 1.2.
(4) By service life, it can be classified into the temporary slope and permanent slope, the service life of permanent slope is more than two years.
In addition to the above classification, the slope can be classified due to the form of supporting structure (Zhao, He and Wang, 2003).
There are many types of slope failure, collapse and landslides that are common. Part of the rock and soil in front of the steep slope suddenly separated from the main part, the process of tumbling crash caving or falling to the bottom known as the collapse.