Page 20 - Building Regulation and Design Guidelines - Structural (Grey Code)

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

• Range of soil (particle size-sieve analysis) suitable for vibratory
techniques are zoned in Fig. (1.19) Indicating the best improvement Stone Columns Dynaminc Replacement Controlled Modulus Coloumns
technique suitable for such soil. Fig. (1.20) Shows the most suitable +
techniques for both cohesive and granular soils. Preload
• The prices per cubic meters of the treated soil with respect to
depth for surface compaction, dynamic compaction and deep vibro
compaction are presented in Fig. (1.21) to ease the decision for the +80-100 in
proposed improvement technique with respect to cost for granular +25-36 in
soils COHESIVE SOILS: Clays, Sites, Peats
Range of soils suitable for vibratory techniques
100% Dynamic Compression
90%
80%
70% Compressive Soil
60%
50%
40% D C B A GRANULAR SOILS: Gravel, Sand, Fill
30%
20% Fig. (1.20): The Most Suitable Improvement Techniques for both
10% Cohesive and Granular soils
0%
0.001 0.01 0.1 1 10 100 1000
Particle size (mm)
Price per
0 m 3 treated soil
Zone A: The soils of this zone are very well compactable.
2
The right borderline indicates an empirically found limit
where the amount of cobbles and boulders prevents 4 HEIC
compaction because the vibroprobe cannot reach the (Impact Roller)
compaction depth. DC
6 (Weight Dropping)
Zone B: The soils in this zone are suited for Vibro Compaction. Vibro Compaction
They have a fines content of less than 10%. 8 (Depth Vibrator)
Zone C: Compaction is only possible by adding suitable back-
fill (Material from zones A or B) from the surface (stone 10
columns or sand columns).
Treatment
Depth [m]
Zone D: Stone columns are a solution for a foundation in these
soils. There is a resulting increase in bearing capacity
and reduction on total and differential Fig. (1.21): Cost Comparison for the Different Improvement
Techniques for Granular Soils
Fig. (1.19): Range of Soils Suitable for Vibratory Techniques

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