application of geological data for geotechnical work (clean version) · 2018-03-21 · application...
TRANSCRIPT
Application of geological data for geotechnical work
Tim Chapman BE MSc DIC CEng FICE FIEI FREngArupDirector, Leader of Arup’s Infrastructure design group in London Geotechnical [email protected]
Large project next to Waterloo station
Plan showing a site with dense network of tunnels, shafts and escalators under one end of the building
The solution that received planning permission
Photos showing that viewing corridors are a more significant constraint as they preclude the granting of Planning Permission – hence the foundation solution has to cope with extreme geotechnical constraints
The geotechnical engineer struggles with….
• 19 different consultants all clamouring for client attention
• Many project constraints and drivers in addition to the ground
• We don’t generate enough crises! (fortunately…)
• Urban planning- Viewing corridors, transport access, section 106 payments
• Building planning- Fire, M&E plant space, letting configurations
How is geological data used?
Design – standard processesStratigraphy
Characterisation of strata
Water pressure distribution
Parameters for design
Risk mitigation – “drama”!Topography
Man‐made- Archaeology ‐ protect- Contamination- Tunnels ‐ protect- Obstructions – avoid?
Geology and hydrogeology- Faults- “Scour hollows”- Changes in stratigraphy- Unexpected clay swell !- Water flow
Conundrum
• Cost of investigating ground is shockingly low
• Yet ground risks are one of main causes of
project delay (50%), and of• Insurance claims on completed projects – eg NHBC
• Serious for buildings – 0,1% of project budget spent on SI
• Can be catastrophic for major infrastructure eg tunnelling
• Challenge to the industry is for even greater efficiencies
• 33% cut in project costs sought by government
“… as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns— the ones we don't know we don't know.”
Expect the Unexpected
Former U.S. Secretary of Defense Donald Rumsfeld explained a state of intelligence at a US Defense Department Briefing on 12 February 2002
Data flows – geological data at the macro level
Enable much better appreciation of geological hazards – desk study
Turn “unknown unknowns” into “known unknowns”
Reduce ignorance!
“If you do not know what you should looking for in a site investigation, you are not likely to find much of value”
– Rudolph Glossop (1968 Rankine Lecture)
Industryshares data
Body gathers data
Synthesise data Disseminate
Big data! First of the 8 great technologies
The future!
“The Government Construction Strategy was published by the Cabinet office on 31 May 2011. The report announced the Government’s intention to require: collaborative 3D BIM (with all project and asset information, documentation and data being electronic) on its projects by 2016”
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Information Management
Information Modelling
BIM maturity level
0
1
2
3 ‘holy grail’
No project wide common standard for flow and
production of information
A project wide consistent approach to flow and
production of information
As BIM level 2
2D CAD and paper issue
2D/3D CAD produced independently by team
members
3D models produced by all team members to common level of detail using common tools
Single project model
BIM maturity level definitions
A project wide consistent approach to flow of
information
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HS2 catalyst for change….
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Potential of BIM to transformgeological data flows at the project level
• GI data and our interpretation
• All reports will be completely public, all interpretation will be open to scrutiny
• Collaboration through the design process – real or formal?!
GI Data Piling contractorConsultant
Drawings
Site tablet
Piling
RecordsSetting out
Other site opsMaterial properties
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BIM attributes for a geotechnical element
Design of the elementLevels of Development LODs Attributes
Ground investigationChoice of GI techniques and locations
Desk studyUnderstanding all of the issues
ART ART
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Great new geological data… developed knowledge!
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Insatiable demand for data processing
But is it wise?
How to feed the beast while maintaining quality
Geological risks are wildly random and so not directly amenable to statistical reduction
John Burland’s “well winnowed experience”
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The “Second machine age”a new dawnPower of machines to replace manual tasks• now mastering complex tasks like driving• autonomous vehicles now on our roads
Future opportunities to exploit power is exponential ‐ thanks to Moore's law
Far more agile data collection and handling, Automation of on‐site processes, Instrumentation much cleverer• How far will this intrude into geotechnical data collection and design?• How can better geological data systems be most useful?
People• Shortage of skilled people• What happens to the people without skills? Can they find other jobs?!
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A better future?
Process and efficiency versus wisdom and reliability
Let us master the copious data, improve our processes but not neglect wisdom, or we lose the reliability that we need
