| Soil Condition | I | 
| In the case of hard rock (e.g., granite, limestone, basalt, hard sandstone) in a structure of uniform strength | 1.0 | 
| In the case of soft rock (e.g., soft sandstone, clay shale, marl stone) and in the case of hard rock with alternating stratification or with numerous fissures | 1.1`1.2 | 
| In the case of mantle rock (e.g., non-cohesive soils such as gravel, sand, cohesive soils, silts or clays with a consistency better than stiff) | 1.2`1.4 | 
@
: Reduction factor depending on structure class (See Table 3, Table 4)