516
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Drainage basins of
Chenyulan Creek
Drainage basins
of Cishan River
Watershed of
Nahua reservoir
Drainage basins
of Laonong River
Drainage basins
of Ailiao River
Taitung Area
Drainage
Basin
County Line
Survey Area
Figure 2. Survey area conducted by Sinotech Engineering Consultants
survey team.
2 CAUSES AND MECHANISMS OF FAILURES
Flood and heavy rain are two main reasons causing slopeland
and road failures. Depending on different geological
environments, the survey team concluded ten mechanisms of
slopeland and road failures. Table 1 listed these mechanisms
and numbers of failures caused by each mechanism.
Figure 3 to Figure 12 show failures caused by Mechanism
No.1 to No.10. One mechanism should be noticed is Complex
Failure Mechanism. Complex Failure Mechanism means that
slopeland or road failures were caused by more than one
mechanism simultaneously. Damages caused by Complex
Failure Mechanism were usually severe and massive. Figure 12
shows one failure site (County Road 64 in Taitung County)
damaged by Complex Failure Mechanism which included
Erosion of Bottom Roadside Slope and River Channel Erosion
of Roadbed mechanisms.
Table 1. Failure Mechanisms and Number of Failures
No.
Failure Mechanism
# of
Failures
1 Erosion of Bottom Roadside Slope
35
2 Debris Flow
33
3 Erosion of Top Roadside Slope
27
4 Shallow Slope Failure
22
5 River Channel Erosion of Roadbed
21
6 Dip slope
4
7 Circular Failure of Slope
4
8 Barrier Lake
2
9 Deep Sliding Failure of Colluvium
2
10 Complex Failure Mechanism
15
Figure 3. Failure caused by Erosion of Bottom Roadside Slope
Mechanism (Provincial Highway 21 (228K+500)).
Figure 4. Failure caused by Debris Flow (County Road 179 in Nantou
County).
Figure 5. Failure caused by Erosion of Top Roadside Slope (County
Road 60 in Nantou County).
Figure 6. Failure caused by Shallow Slope Failure (River in Tao Yuan
District in Kaohsiung City).
