algerian earthquake resistant regulations « rpa 99 - IISEE

CHAPTER II - GENERAL RULES FOR CONCEPTION
2.1. SELECTION OF THE SITE
For the selection of the site, a special attention should be paid to the following unfavourable
or penalizing conditions:
• presence of known active faults
• suspected zones of liquefaction potential
• unstable soils
- unstable slopes, edge of cliffs, banks and shores subjected to erosion
- saturated poorly drained soils subjected to settlement or flooding
- presence of underground cavities
- presence of non compacted fills
• Uneven surface topography
- ridges, peaks
- banks of deep valleys
- surrounding of important slope changes
• Presence of alluvial deposits of variable thickness at the toe of a slope or of important
thickness in the middle of valleys (possibility of amplification).
• Presence of different geological formations.
The final choice of the site will be made on the basis of the investigations the importance of
which will be in accordance with the planned project.
The type and importance of these investigations can be oriented by the results of the seismic
microzonation studies where they have been made.
2.2. SOIL INVESTIGATIONS AND STUDIES
Except for the constructions having a basement with 3 stories at most or having an average
height of 11m (as for individual housing or assimilated buildings) with a total floor area less
than 400m 2 , the soil investigations are mandatory for the constructions classified as of middle
importance and more, sited in zones having a seismicity ranging from moderate to high.
These studies are in principle the same as in the case of non seismic situations but they should
in addition permit to classify the site and to detect the zones of liquefaction and / or other
instabilities
Additional investigations can be necessary especially in the presence of liquefiable or instable
zones and also to take into account the dynamic properties of the soils in design process.
2.3. SITING OF THE CONSTRUCTIONS
While siting the constructions it would be necessary:
- to absolutely avoid the immediate proximity to a known active fault in case of
constructions classified as of medium importance or more. If the lineament of the fault has
been located during a previous site investigation study, the constructions of a medium
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