Table 1 Evaluation factors and grading standard of highway landslide hazard.
From: Evaluation modeling of highway collapse hazard based on rough set and support vector machine
Evaluation index | Evaluation grades | ||||
|---|---|---|---|---|---|
I (C1) | II (C2) | III (C3) | IV (C4) | ||
Topography | (x1) Slope shape of slope | Fold line slope (4) | Concave slope (3) | Straight slope (2) | Convex slope (1) |
(x2) Aspect of slope | Sunny slope (4–3) | Shady slope (2–1) | |||
(x3) Slope of slope/° | > 60 | 40–60 | 20–40 | < 20 | |
(x4) Height of slope/m | > 150 | 100–150 | 50–100 | < 50 | |
Geologic structure | (x5) Meso structure | Development (4) | More development (3) | Less development (2) | No Development (1) |
(x6) Exposed structural face | Development (4) | More development (3) | Less development (2) | No Development (1) | |
Stratum | (x7) Stratum lithology | Loose rock (4) | Cemented chasten (3) | Well cemented half hard (2) | Hard rock (1) |
(x8) Weakness interlayer | Clear (4) | More clear (3) | Less clear (2) | No clear (1) | |
(x9) Relationship between weakness face and free face | Consequent slope (4) | Oblique crossing (3) | Cross slope (2) | Reverse slope (1) | |
Climatic and hydrological geological condition | (x10) Mean annual rainfall/ mm/year | > 1500 | 1000–1500 | 500–1000 | < 500 |
(x11) Rainfall erosion/m | > 0.5 | 0.3–0.5 | 0.1–0.3 | < 0.1 | |
Other factors | (x12) Vegetation cover rate/% | < 5 | 5–15 | 15–30 | > 30 |
(x13) Weathering degree of rock/% | > 30 | 10–30 | 5–10 | < 5 | |
(x14) Earthquake intensity/° | > 8 | 5–8 | 3–5 | < 3 | |
(x15) Human activity intensity | Big (4) | Bigger (3) | Lesser (2) | Small (1) | |
