Environmental Engineering Reference
In-Depth Information
Figure 3.34.
Air photo showing the scar of an old landslide in folded limestone, near the Mubi River,
Papua New Guinea.
overlying beds. Retreat of these beds has produced broad valleys bounded by steep
escarpments, with hanging tributary valleys. James considers these almost “glacial-like”
valleys to be useful indicators of the presence of limestone in areas devoid of outcrop.
3.7.11
Dewatering of excavations in carbonate rocks
Excavations below the water table in carbonate rocks containing cavities are likely to
require more continuous pumping at higher rates than equivalent excavations in non-soluble
rocks. Also because the sizes and distribution of cavities are usually so variable and irreg-
ular, a number of borehole pumping tests at carefully selected locations may be needed to
get a reliable estimate of the inflow rates.
3.7.12
Carbonate rocks - check list of questions
- Category
O or Y
?
- Cavities, air-filled or water-filled?
- Cavities, soil-filled?
