Page 10 - Building Regulation and Design Guidelines - Structural (Grey Code)

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

Term RQD (%)
Very Poor 0 - 25
Poor 25 - 50
Fair 50 - 75
Good 75 -110
Excellent 90 -100

Table (1.4): Rock Fracture State

Uncon ned
Term compressive
strength (MN/m)
Very weak <1.25
Weak Gravel size lumps can be broken in half by heavy hand pressure. 1.25 to 5
Moderately weak 5 to 12.5
pressure
Moderately strong When held in the hand rock can be broken by hammer blows. 12.5 to 50
Low priority range Intermediate High Very High Extremely High Strong When resting on a solid surface, rock can be broken by hammer blows. 50 to 100
L I H V E Very strong Rock chipped by heavy hammer blows. 100 to 200
Extremely strong Rock rings on hammer blows. Only broken by sledgehammer. <200
Table (1.5): Rock Strength Classification
Plasticity index % Parameters Sandstone Conglomerate

Dry Density (Mg/m 3 )
1.35 to 1.83
1.50 to 1.63
0.81 to 3.18 3.14 to 5.15
Strength (MN/m 2 )
Table (1.6): Sandstone / Conglomerate Properties
Liquid Limit, %
Reference: BS:5930.1999
Table (1.2): Soil Classification System Type of Soil Modulus of Elasticity (MN/m 3 ) Poisson's Ratio

Soil Parameters Loose to Medium Dense to Engineered Loose Sand 10.35 - 24.15 0.20 - 0.40
Medium dense dense to very dense Medium Dense Sand 17.25 - 27.60 0.25 - 0.40
dense
Bulk Density (Mg/m 3 ) 1.6 1.8 1.9 2.0 Dense Sand 34.50 - 55.20 0.30 - 0.45
Submerged Density (Mg/m 3 ) 0.6 0.8 0.9 1.0 Silty Sand 10.35 - 17.25 0.20 - 0.40
Internal Friction Phi (degrees) 25 - 30 30 - 35 35 - 40 > 40 Sand and Gravel 60.00 - 172.50 0.15 - 0.35
pressures K 0.58 - 0.50 0.50 - 0.43 0.43 - 0.36 0.36 Soft Clay 4.10 - 20.70
K 0 a 0.44 - 0.33 0.33 - 0.27 0.33 - 0.22 0.22 Medium Clay 20.70 - 41.40 0.20 - 0.50
K p 2.46 - 3.00 3.00 - 3.60 3.00 - 4.50 4.50 41.40 - 96.60

Table (1.3): Soil Properties Correlations Table (1.7): Elastic Parameters for Various Soils

18 19