Page 15 - Building Regulation and Design Guidelines - Structural (Grey Code)

SECTION: 1 GEOTECHNICAL GUIDELINES & REGULATIONS SECTION: 1 GEOTECHNICAL GUIDELINES & REGULATIONS

safe temporary slope of 35 degrees to the horizontal. Recommendations 1.3.5 DEWATERING: Care should be taken during dewatering to ensure
for the safe angle for open excavation in different related soil and / or that fines are not removed during pumping since this could result in
rock materials are to be provided, in accordance to related technical unpredicted settlements of the surrounding ground and associated
guidelines and local requirements. structures.
1.3.3 BACKFILL MATERIALS AND COMPACTION CRITERIA: The material used - Fig. (1.10) Indicates Surface Dewatering System (French Drains).
for backfilling purpose (Maximum 2.00 m thickness) shall be of selected
fill composed of sand/granular mixture free from organic materials - Fig. (1.11) Indicates Well Point Dewatering System
or other deteriorates substances. The Plasticity Index of the backfill - Fig. (1.12) Indicates Deep Wells Dewatering System.
material shall not exceed 10%. The maximum particle size of backfill
material shall not exceed 75m and the percentage passing 75m Sieve - Fig. (1.13) Shows the Well Pit Details during running dewatering and
shall not exceed 20%. The organic materials content should not exceed after dewatering
2% and the water soluble salt content shall not exceed 5%. The backfill - Fig. (1.14) Indicates the Details of Dewatering Deep Well
materials shall be placed in layers of thickness 150mm to 250 mm and
to be compacted to not less than 95% of the maximum dry density.
The specialist must state whether the material available in site could
be used for general backfilling or not after performing the necessary 50-100 cm
analysis. Sand cone test may be carried out to determine the degree of
compaction while the plate load test (as per ASTM D1195/D1195M– 09)
also is an acceptable test where the bearing capacity corresponds to the
allowable settlement will be confirmed. m
o

0 100-150 mmPVC Slotted Pipe
1.3.4 RETAINING STRUCTURES: The specialist must recommend the most 0 1 -
preferable shoring system, Fig. (1.9), (if required) as well as the soil 0 8 Geo Textile Wrap
parameters to be adopted for the design as per Table (1.3).
Step Walls Concrete Water
Seal above
Ground
Complicated
Ground Final Excavation Level

Deadman
and
Brace Raker Helix
and
above Fixed Tieback Typical Section of French Drain System
Ground Length Anchor
Fig. (1.10): Surface Dewatering System (French Drains)
E-80
Cooper
ah External
av Railroad
Force
Surcharge on Wall
and Lagging
Limited Embedment Earthquake Spacing
due to bedrock
Fig. (1.9): Shoring Systems
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