Week 2 Ground Investigation Flashcards
What is the definition of ‘Ground Investigation’ according to BS5930:2015?
Ground Investigation (GI) is the broad process of gathering all relevant information regarding a site.
What was the previous terminology used for ‘Ground Investigation’?
Site Investigation (SI)
Which standard outlines the sequence and considerations for Ground Investigation?
BS5930
What does Eurocode 7 cover?
Details regarding requirements for laboratory and field tests, interpretation and evaluation of results, and derivation of geotechnical parameters and coefficients.
What factors may lead to inadequate Ground Investigation?
- Procured on the lowest price
- Not designed/supervised by a geotechnical engineer/engineering geologist
- Not accommodating the final construction option adopted
- Budget spent on other aspects of GI/SI
What should a Ground Investigation aim to obtain according to BS5930 Section 1?
- Reliable information for economic and safe design
- Assess hazards associated with the ground
- Meet design and construction requirements
- Verify and expand previously collected information
What is a geotechnical ‘risk register’ (GRR)?
A document that identifies risks that the ground conditions could pose to the proposed construction project.
What are the phases of a Ground Investigation?
- Phase 1: Desk study and field reconnaissance
- Phase 2: Preliminary investigation
- Phase 3: Detailed investigation
- Phase 4: Control investigations
What does a Preliminary Sources Study Report (PSSR) provide?
A preliminary engineering assessment based on the desk study information.
What is included in a Geotechnical Design Report (GDR)?
Design of planned works and a risk assessment based on ground hazards.
What should the objectives of fieldwork be?
- Ensure economical and appropriate foundation design
- Evaluate risks and potential design constraints
- Reduce uncertainty about ground conditions
What factors affect the nature of the fieldwork in Ground Investigation?
- Character and variability of the ground
- Nature of the engineering project
- Amount of existing information
- Spacing of investigation locations & depth of interest
What are the three broad categories of methods used to investigate ground properties?
- Intrusive methods
- Non-intrusive methods
- Testing methods
What are intrusive methods?
Methods which disturb, excavate or remove soil/rock.
What are non-intrusive methods?
Methods which do not disturb the ground material.
What are testing methods in Ground Investigation?
In-situ methods which test soil/rock properties directly.
Fill in the blank: The depth of interest below foundation/excavation depth for raft foundations should be at least _______.
1.5x the smallest side of the proposed foundation/structure width
