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The Clay Research Group Issue 109 – June 2014 –

The Clay Research Group

Monthly Bulletin

TheClay Research

Group

June 2014Edition 109

RESEARCH AREAS

Climate Change Data Analysis Electrical Resistivity Tomography

Time Domain Reflectometry BioSciences Ground Movement

Soil Testing Techniques Telemetry Numerical Modelling

Ground Remediation Techniques Risk Analysis

Mapping Software Analysis Tools

The Clay Research Group Issue 109 – June 2014 – Page 1

CONTENTSIssue 109, June, 2014

Page 1 & 2The Aston Subsidence Conference.

Page 3Intelligent Systems ‐ Introduction

Page 4Google Tablets and Apple Phones

Page 5Higher Temp = Fewer Claims

Page 6Conservatories are High Risk

Page 7Sundry Updates

Page 8 & 9Clay – the frequency risk

Page 10 & 12Aston Conference – 10 years on

Page 13Research News

Aston Subsidence Conference

We are looking forward to the conference this year.Attendees will have the opportunity of catching upwith the latest news and developments in case law,but also the growing use and value of analytics in ourindustry. We will see and how they are being used bycompanies to improve their performance and insome cases, change the way service is delivered.

Understanding ‘how many of what sort’, ‘when’ and‘where’ is central to what we do. Without somerecord, every claim is a surprise. The use of so‐calledBig Data helps us to understand what we do, anddrives improvement.

Tony Boobier sets the scene when he tells us abouthis unique experience spanning subsidence handlingat all levels and managing analytics for the insurancedivision at IBM.

Later in the day, Paul Stanley reveals how he usesnew technology to speed up the claims process.Removing touches and providing the insured withoptions on service delivery by using live streamingand a ‘self‐serve’ option. What tools are availableand how might they be used to drive down cost andspeed claim settlements?

Tom Clinton and Steve Plante will be providingupdates on current research and explaining theirobjective ‐ to reduce the trauma of subsidence.

Measuring the success or otherwise of thesedevelopments is essential, which leads us back to theuse of analytics. Richard keeps the whole thingtogether ensuring the day runs smoothly, concludingby talking about the state of adjusting.

Find out how things are changing by attending thesubsidence conference at Aston.

Aston ‐ 10th Anniversary

It is the 10th anniversary of the AstonSubsidence Conference and previoustopics are reviewed in this edition.

A recurring theme has been the marriagebetween technology and service. Doesone really exclude the other? How canthey best be combined to improve ourexpertise, speed up the claims processand ensure high levels of satisfaction foreveryone concerned?

This year continues the theme and wehear how technology and research isreinforcing service delivery.


This is the 10th Anniversary of the AstonSubsidence Conference and a review of pastprograms helps to describe its objective.

In 2004, Richard Driscoll chaired the day andspoke about the need for data and pondered thebenefit of 30 years of research, reflecting on thework of the Building Research Department in histime as Head of Foundation Research.

Giles Biddle spoke about “Mitigation, Educationand Investigation”. He wondered about thebenefit of soils investigations and said “In thevast majority of cases all other investigations(trial pits, boreholes, soil analysis) areunnecessary. They are usually a complete wasteof money, and, worst still, a distraction and causeof delay.”

Both talks are as relevant today as they were tenyears ago.

In 2005 we heard from the insurance claims andadjusting community, including John Parvin,Robert Sharpe, Gary Strong and Nigel Barham.

Nigel’s talk was entitled “Startreck ‐ the nextfrontier”. Robert spoke about “Global Warming –Modelling the Effects and Discussing theImplications”

Again, topics as relevant today as then and arecurring theme over 10 years.

Hilary Skinner from the BRE gave a talk on theCRG proposal to explore electrokinesis osmosis(EKO), something that has been threatening foryears and an area that is only recently reachingfruition thanks to the efforts of Tom Clinton, JohnPeterson (Foundation Piling) and Dr Ian Jefferson(Birmingham University).

In 2006, Gary was joined by Jill Hunt fromLloyds TSB when they asked if there was roomfor both service and technology.

Tim Freeman reinforced the views expressedearlier by Giles when he promoted the use ofprecise levels. Tim’s background working at theBRE led him to the view that they are the mostuseful of tools to diagnose subsidence. Tim isthe author of “House your House got Cracks?”.

Nigel Cassidy from Keele University reviewedalternative techniques of sub‐soil investigationincluding ground imaging and electricalresistivity – something the Glenda Jones, thePhD student from Keele, spoke about at a laterconference.

Malcolm Cooper provided an underwriters viewof subsidence. Not the most costly of perils, butcapable of delivering a nasty surprise.

In 2011 we heard from four of the majorpractitioners in the arboricultural world. Gilesspoke again, but this time proposing “ARealistic General Protocol for Investigation ofTree‐Related Subsidence”. Mike Lawson talkedabout “Planning for City Trees – PuttingSubsidence in Context”. Peter Osbornemischievously posed, “Councils – the root ofthe problem?” and finally Paul Thompsondelivered a thought provoking video entitled“Mitigating the Environmental Impacts ofBuilding Subsidence”.

Mike Lawson spoke again in 2012. “An Analysisof Clay Soil, Climate and Plant Interaction asthis Relates to Claim Numbers 1975‐2011”.Other speakers included Paul Harris and MaciekKawecki. Many more speakers on a wide rangeof topics, but we see the theme


Intelligent Systems ‐ Analytics

The industry has dealt with over one‐and‐a‐half million subsidence claims over the last 50years. We have a reasonable understanding of the risk posed by the geology, the interactionbetween clay soils and vegetation, drains and non‐cohesive soils, age of house and so forth.In this and subsequent editions we look at those relationships with a view to developingsystems to assist practitioners and improve the business process.

The above illustration contains some of the modules we will be examining in future editions.Spatial distribution of claims, their periodic signature (where it exists) and how we mightbuild a series of intelligent modules that learn from their experience.


Surveys using Google Tablets and Apple iPhones

In Issues 105 and 107 we looked at developments in surveying. LiDAR cameras fixed towobbly springs that took millions of readings and allowed the surveyor to carry out adetailed survey of the Leaning Tower of Pisa in about 20 minutes.

How far off are we from being able to plug into this technology? A browse of the webrevealed that Apple had already lodged a patent application to incorporate this into itsiPhone using what they call iBeacon technology.

This was only a few months ago.

Such is the excitement amongst the larger technology companies that they may havefound a route into the domestic subsidence market (yes, we do have our tongue in ourcheek), Google have reported that they will be offering a tablet that can measurerooms and build 3D maps under their “Project Tango”. The cost is likely to be around£600 and 4,000 beta test kits will be available in the next month or so.

£600 isn’t expensive when we consider the value in time saving alone for the busysurveyor plus the accuracy it delivers. Having a base map that can be digitally sharedby all – homeowner, insurer, repair contractor etc. – is a huge step forward.

The press release explains “the device maps the world in 3D through the use of twocameras, one on the front that can see 120 degrees, and a 4MP camera on the rear. Amotion tracking camera on the back also helps the mapping process, in addition to anintegrated depth sensor. These sensors allow the phone to make over a quarter million3D measurements every second, updating it’s position and orientation in real‐time.”

This opens the door to the nextgeneration of claims handlingsoftware. Instead of having asketch pad with a hand‐drawnmap scanned into your systemas a pdf file, we can start tothink how we might automatemore of the processes. As forservice, fast, accurate surveysthat lead to accurate diagnosisand improved pricing has tobenefit everyone.


Higher Temperatures = FewerClaims

The temperature may have levelled outover the last 15 years or so, but where arethe claims?

Bottom right, the trendline analysisreveals that since 2006 claim numbershave been reducing which may seemperverse. The industry was anticipating anincrease.

Although temperatures may have reacheda temporary plateau, they are amongstthe highest since records began and thisperiod of apparent temperature stabilitycontains some of the hottest years inrecorded history.

The reason for the reduction in claimsappears to be related to the associatedincrease in atmospheric humidity. Theresult has been a trend towards wettersummers.

The figure, centre right, plots the totalrainfall in July, August and September. It’slittle use summing rainfall throughout thewinter when many trees are out of leaf.Here we have attempted to see whathappens in the summer months using MetOffice data gathered from their station atHeathrow.

See also editions 94 & 95 for rainfallanalysis by Cyril Nazareth.

If this is the case, the hotter we get, thefewer claims the industry receives.

Subsidence claim numbers from the ABI showinga diminishing trend over the 10 year period

plotted.

Rainfall in the summer months of July, Augustand September showing an increasing trend.

A range of temperature graphs exist but settingaside any dispute around causation, station

variability and methodology, there is agreementthat temperatures are rising.


Interestingly, the primary cause of damage has been rootinduced clay shrinkage as shown below. Foundations onclay soils have not been taken deep enough to cater for theinfluence of roots from nearby vegetation.

It also appears that the FOS are hardening their approachTo such claims and supporting repudiations under theDefective Design or Construction exclusion where theimplicated vegetation was present at the time ofconstruction.

Claim Incidence ‐ Conservatories

The number of valid subsidence claims relating to damaged conservatories is plottedbelow, by year of notification, rather than date of construction. Although subsidenceclaim numbers in general have been reducing over recent years, the percentagewhere conservatories are involved is rising steadily.

The data has been taken from a sample of around 36,000 valid claims.

We would be interested to hear from anyone willing to share FOS decisions on thistopic.


Aerial Survey Update

Bluesky are updating their aerialsurvey of the UK.

James Eddy, Technical Director ofBluesky International explains on theirweb site, “previous estimates of treecover were around 10 per cent forEngland and 13 per cent for the UK asa whole,” commented

“Using our National Tree Map we haveestimated this figure to be marginallyhigher at around 13.5 per cent forEngland and Wales.”

Levels –v‐ Cracks

Plotting a small sample of crack andlevel readings undertaken byGeoServ (see right) reveals anapparent relationship. We arehopeful that Tim Freeman, their MD,will have time to plot data from hislibrary of claims and provide a moredetailed report to understand if therelationship is robust over a largersample.

Bluesky completed the National tree Map in 2013. “Itincludes three individual map layers, detailing more

than 280 million trees with a canopy cover in theregion of 20,000 square kilometres.”

http://www.bluesky-world.com/

A Global View

An application from New Scientist is wellworth a look. Drag the blue marker toany part in the world, and thetemperature line for the last 100 yearsappears in the top, right hand corner.See the variations around the world

http://warmingworld.newscientistapps.com/


Across the UK, the picture isn’t very different. Although there are over 2.5 times the number ofhouses not built on clay soil than ‘other’ (mixtures of sands, gravels rock and so forth) thefrequency of subsidence claims related to houses on clay soils is 2.5 times greater than houses builton these non‐clay soils.

In last months edition we saw that the frequency of valid claims relating to houses built on clay soilwas 0.2% (for the sample we hold), compared with 0.07% for ‘other’ soil types, indicating thatLondon clay is nearly 3 times riskier than the alternative, non‐cohesive, soils.


Private Housing‐v‐

Social Housing

Using the same UK sample fromthe previous page, but excludingsocial and Local Authorityhousing, we see the risk to theinsurer of private residentialhousing increases by just over22% on ‘other’ soil types, andjust under 26% for houses onclay.

This is because a frequencycalculating including all houses,insured or not, distorts the riskfactor significantly.

SMD UpdateData Courtesy of the Met Office

Soils in the south east are still quite wet(see below) and there is no suggestion yetof a surge year.

The caveat is shown above. 2006 started lateand followed the current profile before rapiddrying took place later in June to deliver highclaim numbers.


The Aston Subsidence Conference has beenrunning for 10 years in its present form.Earlier conferences were largely directedtowards describing underpinningtechniques, or the need for sleeving andanti‐heave measures when piling.

If we cast our mind back to how things usedto be, we can see just how much thingshave changed.

In the 1990 surge, an adjuster would makean initial inspection and report back toinsurers using what was referred to as aPreliminary Advice. If the claim was ikely tobe valid, they would request permission toappoint an engineer.

The engineer would inspect, produce areport and pass it back to the adjuster who,in turn, would forward it on to the insurerwith their comments on liability. Often theywould be asking permission to undertakefurther investigations ‐ trial holes andtesting drains. Possibly sink boreholes.

Little industry data was available for thepractitioners. The insurance claims handlerwould be working off the company main‐frame. They would log policy details, claimvalidity and register payments, but theywould have little objective idea of howadjusters and engineers were actuallyperforming.

The absence of data also hampered theadjuster and engineers development.

The large number of subsidence claimsnotified in 1990 was a wake‐up call to theindustry and led to significant change. Theroles of adjuster and engineer were mergedover the next five to ten years andadjusting practices started to employengineers and train them in policyinterpretation and insurance law.

Claim departments and adjusting practicesstarted to build their own computerapplication to measure performance andproduce MI. This wasn’t always a pleasantexperience. Questions were asked – “whydoes ‘x’ engineer, living in a safer part ofthe country in terms of subsidence risk,underpin more properties than his or hercounterpart living in a riskier part of theUK?” and “How do the spends compare?”.

These changes combined with the controlsenabled by IT systems (together with theadvantage offered by a VAT free service)led to the introduction of DelegatedAuthority. The adjuster/engineer no longerhad to refer back to the insurer forinstructions at every stage. They could takedecisions. Decisions that would bemeasured by all parties to provide a degreeof comfort and speed the claims process.

On the technical side and in parallel,excellent work was being undertaken bythe Building Research Establishment. Aseries of informative Digests supported theidea that underpinning wasn’t alwaysnecessary.

Constant Change and Development


The BRE provided advice on how siteinvestigations might be conducted, explainedthe use of precise levels and promotedimprovements in soil testing andinterpretation. They measured groundmovement over a period of years usingground rods set at differing depths toimprove our understanding of root inducedclay shrinkage.

This was supplemented by the work ofconsultants from across the industry. GilesBiddle’s “Tree Root Damage to Buildings” isstill a reference work for us all and is oftenused by experts in litigation.

Clive Bennett from MatLab developed newmethods to detect desiccation in clay soilsfaster and at less cost.

The net benefit of exploring newtechnologies and business procedures hasled to a 50% reduction in the settled cost ofclaims, taking into account inflation. Fewerhouses are underpinned and piling isexceptional.

Education, technology and systems led to animprovement in claims handling. No more‘it’s in the post’ communication delays. Costsfell. Companies knew where they were –those that had built systems at least.

Some still clung to the idea that progress is astep in the wrong direction. Too muchautomation is an issue. Measuring the adviceprovided by professionals using MI isregarded by some as an affront to their skills.

The fact of the matter is, there are no trainingcourses dealing with domestic subsidence orsmall scale geotechnics for engineers,adjusters or surveyors. Practitioners are oftenleft to learn on the job. This lack of experienceand expertise no doubt had a role in theapparent over‐spend 20 years ago.

Professionals would see a black, silty muddysoil beneath a foundation damaged by aleaking drain, and would almost certainly haveunderpinned on the basis that the groundwould not recover. This wasn’t based on anyparticular geotechnical expertise, althoughsome geotechnicians may have said the samething.

Empirically we discovered that, in most casesat least, by repairing the drain and allowingthe soil to dry stability usually returned.

So, back to Aston. What is the point?

Claim numbers have been falling steadily overa period of time when the speed of change hasbeen increasing rapidly. It would be easy tolose interest. After all, subsidence is one of thelower value (although more technical) perilsfor insurers.

There have been many exciting developmentsover the last 10 years, and Aston hasshowcased most of them.

LEGAL ‐ tree root litigation is being refinedwith almost every new case, andinterpretation remains central when assessingliability. Aston has had a legal expertaddressing the audience most years to keep usabreast of developments.

Changes … continued


ARBORICULTURAL. Arboriculturalists andplant physiologists carry out a huge amountof research. Given that 70% of claims relateto trees in a busy year, their role is centraland they have been represented nearly everyyear, sharing their expertise in terms of risk,diagnosis and litigation.

One of the more interesting talks in this fieldwas delivered by Jake Tibbetts, the TreeOfficer from Islington Council.

Jake described in detail the issues faced byTree Officers on a daily basis and identifiedsome of the areas where insurers and localauthorities can reduce the conflict by talkingto one another in a language everyoneunderstands.

Simply presenting a bundle of technicalpapers and asking for a tree to be felleddoesn’t help when the Tree Officer has todeal with objections from residents,Councillors and so forth.

His slides illustrated cases where thehomeowner with the damaged house wasobjecting strongly to the tree that wascausing the damage to be felled. He wantedhis insurers to underpin his home.

In a similar vein, Paul Harris reinforced theproblems faced by tree officers whenengineers submit technical reports withoutexplanation. Not everyone is a geotechnicalengineer, or can understand monitoringrecords.

Paul also found the automation of reportproduction unhelpful. Detailed description ofgeological series for example, taken fromstandard text, didn’t add much in his view.

GEOTECHNICS – Methods of testing clay soilsfor desiccation have moved on. Progress hasbeen made refining the suction test andidentifying some initial teething problemsassociated with filter paper calibration.MatLab led the field when they refined theoedometer tests to cater for disturbedsampling and delivered a fast service withimproved estimates of swell.

Clive Bennett then went on to develop a newsensor that would allow samples to be testedwhilst in the back of the van on their way tothe laboratory from the test site.

All of these developments have beensupported and explored at conferences.

CLAIMS HANDLING has also been overhauledand this year’s conference touches on somerecent innovations.

Now we have improved communications anda choice of how we make contact betweenthe various parties.

These coincide with the current thinking ofthe FCA who have recently asked foralternative communication routes to beintroduced. Again, Aston is where we havethe opportunity to see this new technologyas applied to insurance claims.

Aston – 10 year review – Topics and Speakers


Risk modelling software has improved andsupporting applications have kept pace. TheViscat style of modelling, building a uniquegeology of the UK specific to risk, datareading software, models that take accountof tree species, metrics, climate, soil andproperty have all been displayed at Aston.

RESEARCH ‐ several alternative groundtreatments are being explored and ourcurrent thinking is they may well becombined in one form or another to resolveroot induced clay shrinkage claims quicklyand cheaply.

Recognising the environmental issues weface, the objective is to retain the treewherever possible. This means replacingunderpinning and piling with less intrusivesolutions that are easy to apply, and costeffective.

BUSINESS ‐ Knowing more of what we do,where and ‘counting the beans’ has led tothe introduction of new business models.Data analytics – the world of Big Data – iswith us and every month the CRG share theoutput from their analysis, some of which isdelivered at Aston.

Hopefully the CRG newsletter helps thosewith limited access to subsidence data. Thearticles describe ‘how many of what, where,when’ and sometimes even, ‘why’. Theyassociate geology and trees with risk anddeliver it as a numeric value as we see in thisedition.

So, ‘Why Aston?’ Well, the conference isn’tsponsored by anyone for commercial gain.

The speakers are giving their time withoutcharge to share their knowledge. It is ameeting place for the subsidence industrywith the objective of improving standardsthrough innovation and to share breakingnews on current developments.

We welcome hearing from anyone whowould like to speak at future events. If youhave advice on how we might improve theday, or topics you would like covered, pleaselet us know.

A welcome pack will be sent through shortlyproviding details on how to get theretogether with the program. On the dayattendees will receive copies of summarypapers provided by speakers.

A program can also be downloaded from ourweb site at www.theclayresearchgroup.orgtogether with issues covering pastconferences. Please contact us if you requireany help.

Aston – 10 year review. Why Aston?


"Arctic study sheds light on tree-ringdivergence problem: Changes in light

intensity may impact density of tree rings."ScienceDaily. 7 May 2014

Stine, an assistant professor of Earth & climatesciences at San Francisco State Universityexplains that tree rings consist of a low densityring, which forms early in the growing season,and a high density ring that forms late in thegrowing season. In colder parts of the world,the dense latewood rings tend to be denserduring warm years.

“Temperature records inferred from Arctic treerings do a good job of tracking temperature upuntil the 1960s, but subsequent Arctic tree‐ringdensities did not correspond with increases intemperature, a discrepancy that is called thedivergence problem.”

The divergence is not a problem forunderstanding modern climate change in theArctic, Stine explained, "because we havethermometers and those thermometers tell usit's warming.

“But it's a problem because if we want to usethese tree rings as a proxy for temperatures ofthe past, we need to make sure that weunderstand what's happening now."

Stine hopes the new findings will lead to amore informed discussion about climatechange.

Ding, et al., “Tropical forcing of the recentrapid Arctic warming in northeastern

Canada and Greenland”.Nature, 2014

Atmospheric scientists from the University ofWashington have estimated that up to half ofthe recent warming in Greenland andsurrounding areas may be due to climatevariations that originate in the tropical Pacificand are not connected with the overallwarming of the planet. Still, at least half thewarming remains attributable to globalwarming caused by rising carbon dioxideemissions.

Greenland and parts of neighbouring Canadahave experienced some of the most extremewarming since 1979, at a rate of about 1degree Celsius per decade, or twice the globalaverage.

"Our work shows that about half of thewarming signal in Greenland comes from thepredictable part ‐ forcing of climate byanthropogenic greenhouse gases ‐ but abouthalf comes from the unpredictable part," Steigsaid. “This makes shorter‐term forecastsdifficult, but helps scientists to make moreaccurate long‐range projections.”

On the face of it, a perverse view given that inthe UK certainly, the Met Office say theopposite.

It is also questioned by some why CO2 getssuch a bad press when, although it continuesto rise unabated, the temperature is fairlysteady and has been for the last 17 years orso.

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