Abstract: The accurate identification of stratum properties is very important to ensure the stability of the slope engineering projects. Under some restrictive conditions, the design of the engineered slope may not be able to obtain the soil and rock samples during the investigation, resulting in the division of actual strata varies from different staff, which lack of an objective basis. The soil and rock engineering properties cannot be accurately characterized thus it could affect the design and construction of a stable slope. The testing while drilling method can capture the soil and rock information carried by the drilling process itself, there is a lack of reliable data analysis methods. By using the Drilling Process Monitoring (DPM) method, this paper proposes a new analytical method of test data during drilling process. By smoothing the space and time scale of the drilling speed, it solves the problem of the random fluctuation of the drilling machine dynamic parameters. This paper presents a case history of a cut slope section from Xiaomangyang to Mohan section in Kunmo Expressway in Yunnan Province. The drilling process of the ground anchor is monitored throughout the entire process, and the monitored data are analyzed smoothly in time and space. The relationship between the drilling penetration rate and lithology is established and the soil/rock strata are identified, which provides a reliable basis for the engineered slope design.

Key words: Weathered Rock, Instability, Drilling Process Monitoring (DPM), Drilling, Monitoring, Penetration Rate