Page 15 - Handbook GEOTEKNIK_Final_Neat

Typical Geotechnical Design Criteria

DESIGN COMPONENT MODE OF FAILURE MINIMUM DESIGN LIFE Remarks
FACTOR (durability of
OF materials)
SAFETY
1. Slope / Unreinforced 1.1 Local & Global Stability 1.3 75 years Analysis should be according to GEOTECHNICAL MANUAL FOR CONTENTS
Embankme 1.2 Bearing (fill) 2.0 SLOPES (1984), GEO Hong Kong
nt (not on
soft ground) Reinforced or 1.3 Local & Global Stability 1.5 75 years
Treated 1.4 Bearing (fill) 1.5
2. Embankment on Soft 2.1 Bearing (short term) 1.4 75 years 5 years post construction settlement:
Ground 2.2 Local & Global Slope 1.3 (i) within 50m from structures approach < 100mm
Stability (short term) 1.2 (ii) within 100m remote from structures < 150mm
2.3 Local & Global Slope (iii) Road < 250mm (Total Settlement)
Stability (long term) Page Page Page
3. Permanent Anchors 3.1 Tensile Resistance 2.0 75 years Geo Spec 1 (1989), GEO Hong Kong BS8081
3.2 Resistance at Soil Grout 3.0 1-29 31-76 79-106
Interface 3.0
3.3 Creep/corrosion
4. Rigid Retaining Structures 4.1 Overturning 1.8 75 years Max. permissible vertical Max. Max.
4.2 Sliding 1.6 movement: permissible permissible
4.3 Overall Stability 1.5 15mm along face of wall lateral differential Site Investigation Foundation Slope
4.4 Bearing 2.0 Geoguide 1 (1983), Geo movement: movement:
Hong Kong 15mm along 1 : 150 along and Laboratory Engineering Stabilization
face of wall face of wall Testing
5. Reinforced fill walls / External Stability BS 8006 120 years Verticality: Alignment Max.
structures ±5mm per metre height along top permissible
Internal Stability (horizontal): differential
±15mm movement: Page Page Page
reference 1 : 100 along
alignment face of wall 109-125 127-137 138
6. Individual Foundation Piles 6.1 Shaft Resistance 2.0 75 years Allowable settlement:
(mainly under axial loads) 12mm along axis of pile at pile head at design load
6.2 Base Resistance 3.0 38mm or 10% pile size at pile head at twice design load Disclaimer
Residual settlement not exceed 6.5mm
BS8004 and JKR Road Specification
7. Individual Foundation Piles Ultimate Lateral Resistance 2.5 75 years Allowable settlement: Max. permissible lateral Ground Instrumentation 139
(mainly under lateral & 12mm along axis of pile at movement: Improvement
bending loads perpendicular pile head at design load 12mm perpendicular to axis of
to axis of pile) BS8004 pile at design load Acknowledgement
8. Pile Group Block Bearing Capacity 2.0 75 years Allowable settlement 12mm at Working Load BS 8004
9. Piles as Retaining As for 4, 6 & 7 above As item 6 75 years As 4 above rigid retaining structures BS 8004
Structures above
xiv PUBLIC WORKS DEPARTMENT MALAYSIA GEOTECHNICAL ENGINEERING HANDBOOK xv