Slide 1Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Evaluation of Geophysical Techniques to Investigate River Embankments

E. Niederleithinger (BAM), A. Weller (TUC), R. Lewis (PGSL) & U. Stötzner

Slide 2Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Elbe Flood 2002

Motivation Methods & Results Conclusions

Slide 3Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Problems

Recent floods (2002, 2005) caused embankment failures

Many embankments more than 100 years old

No maps or drawings, structure of levees and the soil below unknown

Flood protection state affair: different measures in different states

Geophysics not part of standards and regulations (until now)

Motivation Methods & Results Conclusions

Slide 4Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

What is geophysics?

Measurement of physical fields from the surface to detect subsurface features and parameters

Non-destructiveFastCost-effectiveAvoid data gaps

MotivationMotivation Methods & Results Conclusions Methods & Results Conclusions

Indirect propertiesSometimes difficult to interpretNeed some time and budget

Slide 5Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

The project

Partners:

Standard methods DC-Geoelectrics / resistivity Induction EM Refraction seismics GPRInnovative methods IP/SIP RMT MASW GPR arrays

Test sites Old homogeneous levee (clay) Old inhomogeneous levee

(clay/sand) New levee (according to standards)

Calibration Boreholes, CPT, lab…..

Motivation Methods & Results Conclusions

Slide 6Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Test Sites

Motivation Methods & Results Conclusions

Friedersdorf

Löbnitz

Torgau

Slide 7Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Test Site Löbnitz

Motivation Methods & Results Conclusions

Slide 8Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Standard methods:resistivity (1)

distance [m]

elev

atio

n [

m]

top soil

clay,siltl

gravel

sand

Motivation Methods & Results Conclusions

resistivity [Ohm*m]

profile 2road crest

terrain surf.

Slide 9Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Standard methods:resistivity (2)

Profile 1

elev

atio

n [

m]

top soil

clay,silt

gravel

sand

Motivation Methods & Results Conclusions

resistivity [Ohm*m]

land waterProfile 1

distance [m]

Slide 10Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Innovative methods:RMT

position [m]

dep

th [

m]

Motivation Methods & Results Conclusions

Slide 11Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Innovative methods:MASW

position [m]

elev

atio

n [

m]

shear wave velocity [m/s]

Motivation Methods & Results Conclusions

Slide 12Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

(Innovative) methods: GPR (array)

position [m]

elev

. [m

] piperoad

layererratic block?

Motivation Methods & Results Conclusions

Slide 13Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Comparison with reality

Content Motivation Content Motivation Methods & ResultsMethods & Results Outlook Outlook

Calibration (by boreholes, sampling, CPT) absolutely required!

Slide 14Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Test Site LöbnitzRapid reconaissance methods

Induction EM (BfG Lorenz, U Köln)

Geoelektrics „pulled array“ (IGM/IRIS)

GPR-Array (GBM)

Content Motivation Content Motivation Methods & ResultsMethods & Results Outlook Outlook

Slide 15Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Geoelektrik „pulled array“ (IGM/IRIS)

Radar-Array (GBM)

Test Site Löbnitz3D-GPR

Content Motivation Content Motivation Methods & ResultsMethods & Results Outlook Outlook

Slide 16Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Recommendations

Motivation Methods & Results Conclusions

Slide 17Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

RecommendationsIntegration of geophysics into investigation procedures

Motivation Methods & Results Conclusions

Slide 18Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Motivation Methods & Results Conclusions

Slide 19Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Motivation Methods & Results Conclusions

Slide 20Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Conclusions and Outlook

Handbook In German www.deistrukt.bam.de Out this month Translations planned

Regulations New national standard and

recommendations on river embankments out this year

Geophysics recommended/required Deistrukt handbook as reference

Outlook automatisation, multichannel Fast „non-contact“ methods International network?

Motivation Methods & Results Conclusions

Slide 21Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Motivation Methods & Results Conclusions

Slide 22Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Motivation Methods & Results Conclusions

Slide 23Niederleithinger BAM VIII.2 Flood Defence 2008 Toronto

Thank you!

www.deistrukt.bam.dewww.bam.de