Standards and reports

Standards we work to

We use the edition named in the contract or, if none is named, the current one. Where a project calls for another national code, we say so in the report.

Investigation and logging

BS 5930

Code of practice for ground investigations: planning, description and logging of soil and rock.

GB 50021

Chinese code for investigation of geotechnical engineering, used where the designer or client works to Chinese codes.

Field tests

ASTM D1586

Standard Penetration Test (SPT) and split-barrel sampling.

BS 1377-9

In-situ tests on soils for civil engineering purposes.

ASTM D1143

Static axial compressive load tests on piles.

IS 9214

Modulus of subgrade reaction (k value) from field plate load tests.

Laboratory tests

BS EN ISO 17892

Laboratory testing of soil, including particle size distribution (part 4).

Foundation design

IS 6403

Bearing capacity of shallow foundations.

IS 8009

Settlement of foundations.

IS 2911

Design and construction of pile foundations.

Quality

ISO/IEC 17025

General requirements for testing laboratories. Our lab quality system is aligned to it; see quality at Sidco Lab.

ILAC G8

Guidance on decision rules and statements of conformity.

Analysis methods

• SPT N values corrected for hammer energy and overburden, using the corrections of Skempton, Liao and Whitman, and Robertson and Wride.
• Bearing capacity of shallow foundations to IS 6403, checked against settlement (Meyerhof).
• Pile shaft and toe capacity from SPT results.
• Modulus of subgrade reaction from plate load tests, corrected for plate size.
• Liquefaction screening of loose, saturated sands.

What a SIDCO report contains

A sample contents list for a geotechnical investigation report. Each report follows the agreed scope, so a small job may have fewer sections.

1. Introduction: objectives and scope, the proposed structure, and the codes used.
2. Desk study: site location, geology, seismic setting and climate.
3. Fieldwork and laboratory testing: drilling method and equipment, SPT procedure, sampling and the laboratory test schedule.
4. Results and ground model: ground profile from the boreholes, SPT values corrected to N60 and (N1)60, particle size results, design parameters, safe bearing capacity and modulus of subgrade reaction.
5. Foundation recommendations: raft, strip and pad footings, driven and bored pile capacity, and the limitations of the investigation.

Appendices

• Borehole logs
• Particle size distribution results
• Groundwater chemistry
• Liquefaction assessment
• Footing and pile calculations
• Document control sheet