Re-thinking site investigation

Len Threadgold Geotechnics Limited

Presentation to the Site Investigation 2018

Conference London

28th June 2018

THE PURPOSE OF SITE INVESTIGATION

DEFINED LAYOUT DEFINED FRAMEWORK MATERIALS USED ARE SELECTED SPECIFIED and QUALITY- CONTROLLED

GEOLOGICAL LEGACY HUMAN LEGACY

A STRUCTURE IS

THERE IS AN INTIMATE LIFETIME RELATIONSHIP Between a

STRUCTURE and THE GROUND

MANUFACTURED

BUT

INHERITED

IT IS NOT SPECIFIED!!

THE GROUND IS

THE GROUND MODEL

• Every site needs a ground model

• Requires 4D thinking in

space and time

• Investigation should be undertaken with humility; in effect asking the ground about its form, history and properties

• Groundwater profiles and behaviour are an important part

SITE INVESTIGATION IS A PROCESS NOT A PRODUCT

• Engineers have to respond to A HIGHER AUTHORITY - NATURE

• EVERY PROJECT IS A PROTOTYPE

• THE GROUND NEVER LIES – It is unaware of the qualifications of those assessing it or of the sophistication of any analysis used

• For lawyers the OPINION OF THE JUDGE is the highest authority, but they can only make judgements ON THE FACTS AS THEY SEE THEM

THE IMPORTANCE OF SITE INVESTIGATION

• Much guidance has been written about the nature and importance of Site Investigation

• It is vitally important for efficient, sustainable and safe design

• Should be: o of good quality o well funded o well resourced o well structured o timely

• Inadequate investigation leads to:

o cost overruns o delays o inefficiency o waste o unnecessary & inappropriate

environmental impact

THE IMPORTANCE OF SITE INVESTIGATION

Unfortunately, what is blindingly obvious to the geotechnical, engineering geology & environmental communities does not appear to be recognized or accepted by many of its clients, structural engineers, quantity surveyors, developers, insurers and funders

Their focus appears to be on short term costs not long term value or benefit. Perhaps, at the design stage, such costs seem to be a high proportion of early expenditure, before commitment to full project costs. When this has been done SI costs seem trivial.

“PLEASE PROVIDE A QUOTATION”

Clint Eastwood in “Dirty Harry” once said “How lucky do you feel….?”.

John Ruskin once said “There is hardly anything in this world that some man cannot sell a little cheaper and make a little worse. Those who consider price only are this man’s lawful prey”.

Professor Skempton once said “Optimism and overconfidence may impress one's clients, but they have no influence on the great forces of nature”.

We certainly can

PROCUREMENT

• If the differential between prices for SI was 10% of SI cost, appointment of the lowest tenderer would appear to save 0.12% of average project cost overruns or

• Average project cost overruns were 833 times the apparent cost savings on SI by appointing the lowest tenderer for SI

• Actual cost of investigation was 0.21% of original project cost

• Average cost overruns from unforeseen ground conditions = 17.5% of project cost or 83.3 times the SI cost

PROCUREMENT

• This Figure shows a similar picture to the previous one and both feature in ICE 2013 and New Zealand 2017 publications so are still believed to be representative of current practice

PROCUREMENT

VALUE = FUNCTION COST

• The aim of value is understood but..

• The strategy should be to increase value by improving function and seeking quality rather than the lowest price for Investigation, the price of which is dominated by the cost of drilling holes & backfilling

• Investors argue that their salaries reflect the need to pay for quality. Why should this logic change when appointing key specialists?

• Focus should be on confidence and costs for the main project • Appointment should be on merit following a quality-driven agenda

PERCEPTIONS

• Why is this logic not better recognised by investors, insurers and clients?

• Clients need to realise the uniqueness of their site and its interaction with the structure they require.

• How can our industry be better ambassadors?

• Site Investigation is “Site-Specific Research”. Would this be a better term to use?

THE TEAM

• Follow the lead by Sir John Egan in his report “Re-thinking Construction – Constructing the team”

• Establish teams of Consultants, Specialists and Clients with project commitment

• Good communication

CLIENT

DESIGNER SPECIALIST PROJECT

• Collaboration seeks to work to everyone’s strengths • Confrontation seeks to exploit others’ weaknesses

THE TEAM

• Absence of an adversarial approach • The value of mutual trust should not be underestimated • Client-driven focus on overall value rather than short-term cost

• Client ultimately pays for all works

• Phased investigation responding to emerging picture to be promoted

• More time allowed but emerging

electronic communications can minimise the time for this process

TECHNIQUES

• Knowledge of techniques and logistics is the lifeblood of SI specialists • Many techniques with various attributes are part of the armoury • Don’t blame a hammer for not being a good screwdriver • Some are old fashioned but so is the ground – literally!

DRILLERS

• Have valuable expertise and experience

• Have knowledge of access capabilities for rigs and equipment

• Work with Engineers on site to best effect

DRILLERS

• The Royal Shakespeare Theatre at Stratford upon Avon

• Working together! • The show must go on!

LOGGING IS FUNDAMENTAL

• Design engineers need to work with logging engineers and geologists as part of the team

REPORTING - PRESENTATION

• In the past many copies of printed reports were often required. Printing, collating & binding took much time and was costly.

• eg Skipton Western Bypass printed 40 copies of 28 volumes. Delivered to Client by furniture van!

INNOVATION - DATA IN THE AGS FORMAT

• Created by the industry for the industry

• Overcame software incompatibility between providers and users

• All data is rendered accessible for current and future use

• Was BIM compliant 20 years before the term came in to common use

• Was an industry and world-leading initiative

Bites and Terabytes

25th Anniversary Celebration 2017

REPORTING DATA AND INTERPRETATION

NATIONAL DATA

• Glasgow trial - GSPEC • Standardised & validated

subsurface data • Validated data to existing industry

& AGS digital standards • data easily re-useable • data efficiently transferred

between consultants, contractors, local authorities and BGS

• better data sharing – better

understanding – better engineering - efficiency savings

NATIONAL DATA

• Upscaling from Glasgow to UK

• ASK South Wales – UK

launch building and adapting foundations from Glasgow

• Pioneers – key

stakeholders and pilot cities

• Establishing exemplars

and identifying key Knowledge Exchange pathways for followers to emulate

"DATA,""FILE_DOCT"",""REP"",""Report"",""AGS4"",""""" "DATA,""GCHM_CODE"",""WS"",""Water-soluble sulphate (as mg/l SO4)"",""AGS4"",""""" "DATA,""GCHM_CODE"",""PH"",""Acidity/alkalinity (pH to nearest 0.1)"",""AGS4"",""""" "DATA,""GCHM_TTYP"",""WATER"",""Water"",""AGS4"",""""" "DATA,""GEOL_LEG"",""101"",""Topsoil"",""AGS4"",""""" "DATA,""GEOL_LEG"",""204"",""Gravelly CLAY"",""AGS4"",""""" "DATA,""GEOL_LEG"",""220"",""Sandy gravelly CLAY"",""AGS4"",""""" "DATA,""GEOL_LEG"",""504"",""Sandy GRAVEL"",""AGS4"",""""" "DATA,""GEOL_GEOL"",""TS"",""Topsoil"",""AGS4"",""""" "DATA,""GEOL_GEOL"",""WBC"",""Weathered Boulder Clay"",""AGS4"",""""" "DATA,""GEOL_GEOL"",""BC"",""Boulder Clay"",""AGS4"",""""" "DATA,""GEOL_GEOL"",""GG"",""Glacial Gravels"",""AGS4"",""""" "DATA,""GEOL_GEO2"",""CLAY"",""Clay"",""AGS4"",""""" "DATA,""GEOL_GEO2"",""GRAVEL"",""Gravel"",""AGS4"",""""" "DATA,""GEOL_BGS"",""WITI"",""Wilderness Till Formation"",""BGS Lexicon"",""""" "DATA,""HDPH_TYPE"",""CP"",""Cable percussion (shell and auger)"",""AGS4"",""""" "DATA,""HDPH_TYPE"",""IP"",""Inspection pit"",""AGS4"",""""" "DATA,""LOCA_TYPE"",""CP"",""Cable percussion (shell and auger)"",""AGS4"",""""" "DATA,""LOCA_TYPE"",""IP"",""Inspection pit"",""AGS4"",""""" "DATA,""LOCA_TYPE"",""TP"",""Trial pit/trench"",""AGS4"",""""" "DATA,""ISPT_TYPE"",""C"",""Cone"",""AGS4"",""""" "DATA,""ISPT_TYPE"",""S"",""Split spoon"",""AGS4"",""""" "DATA,""MOND_TYPE"",""GCD"",""Carbon dioxide concentration"",""AGS4"",""""" "DATA,""MOND_TYPE"",""GOX"",""Oxygen concentration"",""AGS4"",""""" "DATA,""MOND_TYPE"",""WDEP"",""Depth to water from LOCA_ID datum"",""AGS4"",""""" "DATA,""SAMP_TYPE"",""B"",""Bulk disturbed sample"",""AGS4"",""""" "DATA,""SAMP_TYPE"",""D"",""Small disturbed sample"",""AGS4"",""""" "DATA,""SAMP_TYPE"",""U"",""Undisturbed sample - open drive"",""AGS4"",""""" "DATA,""SAMP_TYPE"",""W"",""Water sample"",""AGS4"",""""" "DATA,""TRAN_STAT"",""DRAFT"",""Draft"",""AGS4"",""""" "DATA,""FILE_DOCT"",""CAL"",""Calibration data"",""AGS4"",""""" "DATA,""GCHM_CODE"",""CL"",""Chloride (as mg/l)"",""AGS4"",""""" "DATA,""MONG_TYPE"",""SP"",""Standpipe"",""AGS4"",""""" "DATA,""MONG_TYPE"",""GMP"",""Gas monitoring point"",""AGS4"",""""" "DATA,""FILE_TYPE"",""DWG"",""AutoCAD document"",""-"",""""" "DATA,""FILE_TYPE"",""DOC"",""Word97 format document"",""-"",""""" "DATA,""FILE_TYPE"",""JPG"",""Image"",""-"","""""

NATIONAL DATA

• COMMON WEALTH OF DATA • NATIONAL RESOURCE FOR UK LTD

HEALTH & SAFETY

PLANNING Toolbox Talks before work starts on site

Planning vital to ensure permissions granted and access available on all projects before a start on site

PEOPLE

• The value of data can only be unlocked by those with experience

• The Register of Ground

Engineering Professionals (RoGEP) was established to provide a reference point for clients seeking help

• A collaboration between

ICE, GSL and IOM3

MONITORING

Instrumentation and monitoring may be considered to be the best means of “undisturbed sampling”, or at least sampling and

testing under the degree of disturbance created by the works

• Data for design • Remote reading has safety benefits

• Data on performance • Feedback for future design

SMART MONITORING

Toe feature of historic landslip Merry Hill, Dudley 1984 aerial photograph (before failure)

• Simple instrument showed movement

• Smart engineers needed to complement Smart technology

Down-Slope direction

Canal

CONCLUSIONS

• BETTER PROCUREMENT STRATEGIES for Site Investigation are needed to SEEK VALUE AND QUALITY rather than lowest cost, to the ECONOMIC BENEFIT OF THE OVERALL PROJECT

• COLLABORATION between the Client, Consultant and Ground

Investigation Specialist team is essential for better engineering and project certainty

• The Industry must BETTER PROMOTE its capabilities and importance

• If gaining knowledge is considered expensive REFLECT ON THE COST OF IGNORANCE

CONCLUSIONS

• EXPENDITURE on Site Investigation of 1% to 2% OF PROJECT COST, approaching 3% FOR TUNNELLING CAN BE JUSTIFIED on both technical and economic grounds.

• Legislation to ensure competent Site Investigation and setting up a body similar to

GEO in Hong Kong would have major benefits to individuals and Companies in the UK in ENSURING SAFETY, SECURITY, ECONOMY AND SUSTAINABILITY

• There have been MAJOR ADVANCES IN THE AVAILABILITY AND USE OF DATA • An accessible ‘COMMON WEALTH OF DATA’ can provide a vital national resource

for the future following the lead by AGS and BGS • BETTER COMMUNICATION by this industry and its ambassadors is essential to get

Clients, funders, lawyers, insurers and government TO BETTER RECOGNISE THE VALUE AND IMPORTANCE OF WHAT WE DO

Any questions or comments?