Flat Dilatometer (DMT) downloadable papers

Prof. S. Marchetti silvano@marchetti-dmt.it       Tel  +39 06 303.60.107

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 3rd International Conference on the Flat Dilatometer:  Rome - June 14-16  2015
  Visualize DMT'15 papers      Conference DMT'15 website

Abstract: A dilatometer test consists of pushing a flat blade located at the end of a series of rods. Once at the testing depth, a circular steel membrane located on one side of the blade is expanded horizontally into the soil. The pressure is recorded at specific moments during the test. The blade is then advanced to the next test depth.

The main application of the DMT is to estimate quickly and accurately Operative Moduli and Settlements of Foundations. Settlements are necessary to the designer e.g. to choose between a shallow foundation or a piled foundation.

Other design applications include: compaction control, detecting slip surfaces in slopes, liquefiability, laterally loaded piles and other geotechnical problems using the soil parameters for which the instrument provides estimates.

When CPT and DMT are executed in sand, three independent significant parameters are obtained : Qcn, KD, ED1 (ED1 = ED / sigma'vo), each one depending on Strength, Stiffness, Stress History. Since three unknowns require three equations, Qcn, KD, ED1 are all needed to solve for Strength, Stiffness, Stress History. Improved predictions are therefore expectable if one-to-one correlations are replaced by three-to-one correlations, or at least by two-to-one correlations. Example of existing three-to-one correlations : OCR = f (ED, KD, Qcn) (Jnl Asce Jan 2014). Example of two-to-one correlations : MDMT = f (ED, KD). For example the correlation relative density DR- Qcn strongly depends on the sand, while the correlation DR - KD strongly depends on OCR (KD increases with both DR and Stress History). It is expectable that a two-to-one correlation DR = f (Qcn, KD) will be better than the one-to-one correlations DR = f (Qcn) or DR = f (KD). Future research will possibly develop multiparameter correlations to replace current one-to-one correlations. A multi parameter CPT-SPT was not possible because both tests provide strength, and even more because SPT is a crude and unreliable test. With the advent of collateral significant independent in situ information - besides Qcn - a multi parameter approach appears a logical development.



2-3 Apr Dubai DFIMEC 2014 "Latest developments on in situ testing, pile-raft foundations and FEM". Lecture by S. Marchetti on DMT.
13 Apr Egypt Tanta University. Emerging Technologies in Field Testing and Soil Characterization. Lecture by Dr. Buselli on DMT - SDMT.
15-16 May Darmstadt Germany. Seminar "All aspects relating to Liquefaction" Technical University, Keynote Lecture by S. Marchetti: "Estimating Liquefaction Resistance taking into account Stress History by DMT".
30 May Hamilton-Ontario CANADA. Workshop on Flat Dilatometer and Seismic Dilatometer by Marchetti, Crapps, Failmezger.
2-6 June Bali Indonesia ICOLD Conf. BALI 2014 - Lecture by Dr. Buselli on DMT - SDMT.
17 June St. Petersburg Russia. Workshop on Flat Dilatometer & Seismic Dilatometer by D. Marchetti ay St. Petersburg Mining University.
2-14 July Australia Brisbane, Newcastle, Adelaide, Melbourne. Workshops on DMT - SDMT by S. Marchetti.
1 Aug Aalborg Denmark. Workshop on Seismic Dilatometer at University of Aalborg, Lecture by D. Marchetti: "Seismic Dilatometer: Description, Results and Applications" .
9-13 Sept Goiania Brazil XII Brazilian Congress on Soil Mechanics & Geot. Engineering, COBRAMSEG 2014. Short Course on DMT - SDMT by D. Marchetti and Dr. Buselli.
22-23 Sept Poznan POLAND 5th International Conference on CPT - DMT. Lectures by D. Marchetti, S. Marchetti, P. Monaco.
9 Oct Pisa Workshop on in Situ Testing at Pisa University, Lecture by S. Marchetti: "Estimating Liquefaction Resistance taking into account Stress History by DMT".
11-12 Nov Jakarta PIT-XVIII Geot. Eng. for Future Infrastructure Development in Indonesia. Lecture by Dr. Buselli "DMT and SDMT for Settlement Prediction of Shallow Foundations and Liquefability Evaluation".
12 Nov Toronto Canada. Presentation on DMT/ SDMT by G. Sedran. Dinner-lecture Canadian Geotechnical Society - Toronto Branch.
18 Nov Bologna Italy. One day Seminar on "In situ investigations" Viale della Fiera Sala BCD della Regione Emilia-Romagna. Sara Amoroso : DMT - SDMT Description of equipment. Results.
1 Dec Concepcion Chile. Presentation on DMT - SDMT by D. Marchetti at "Universidad Catolica De La Santisima Concepcion" Auditorium.
2 Dec Santiago Chile. Presentation on DMT - SDMT by D. Marchetti at " Pontificia Universidad Católica de Chile", Santiago Campus San Joaquín Av. Vicuña Mackenna 4860 Dpto. De Ingeniería Estructural y Geotécnica Sala DIEG, from 13:00 to 14:00.
4 Dec Lima Peru Presentation on DMT - SDMT by D. Marchetti at "Colegio De Ingenieros Del Peru" Av. Arequipa Nº 4947 Miraflores, Lima.
3-5 Dec Moscow Russian Geotechnical Conference. Presentation on DMT - SDMT on 3 Dec by S. Marchetti.
18-20 Dec Kakinada Indian Geotechnical Conference IGC-2014. Presentation on DMT - SDMT at Plenary Session 18 Dec by S. Marchetti.


13 Jan Cesano, Rome Italy Short Course on DMT/SDMT with Field Demonstration.
9-14 May Santa Cruz Bolivia. Geotechnical Conference. Presentation on DMT - SDMT by S. Marchetti.
14-16 June Rome Italy 3rd International Conference on the Flat Dilatometer DMT'15, www.dmt15.com. Under the auspices of Techn. Committee TC-102 of ISSMGE, of the Italian Geot. Society and L'Aquila University. Parco dei Principi.

Using the DMT: The last decades have seen a massive migration from laboratory testing to in situ testing. In situ tests are fast, economical, reproducible, provide many data, have a small scatter, cost much less than sampling and testing. CPT and DMT are today considered practical and fast in situ tests for everyday design (see e.g. State of the Art at the last Geotechnical World Conference 2009). CPT is faster than DMT, hence, in simple jobs, it may be preferable and sufficient. However in important jobs, where accurate settlement predictions are needed, CPT may be not sufficient, because of the well known weakness of CPT to predict accurately settlements (e.g. Robertson 1986, Leonards 1988, Jamiolkowski 1988, Schnaid 2009). The slight additional cost of DMT has been found by many designers a fraction of the savings produced by a better designed foundation. DMT also provides better information on Stress History, which is important for settlements prediction and liquefaction evaluations. When used for monitoring compaction, the DMT's has been found to be twice as sensitive as CPT (Schmertmann 1986). The DMT is also considerably more sensitive to horizontal stresses. Due to the flat shape, arching is negligible, opposite to axi-symmetric probes, where arching obscures the horizontal stress.

Distinctive features of DMT:

The higher ability of DMT to predict settlements is due to:
1. The blade distorts the soil substantially less than conical tips
2. The DMT executes a mini-load test, hence obtains a modulus. A modulus to modulus correlation is closer than a modulus to a penetration resistance, which is a rupture parameter
3. DMT is a genuine two-parameter test, one of which, KD, closely related to Stress History, a parameter having a substantial influence on Settlements and Resistance to Liquefaction.
Arching. The penetration of cylindrical probes creates a stiff soil ring surrounding the probe (Robertson & Hughes 1995). Such obstacle/parasitic screen reduces the sensitivity to sigma-h (Huang 1994). The arching effect is nearly nonexisting with the DMT flat blade, resulting in a higher sensitivity to sigma-h.


Cape Kennedy Space Center
Rome Metro underground
San Andreas Fault area
Nearshore Investigations by DMT
Score table of various in-situ test


SDMT in Costarica

Juan Santamaria Intnl. Airport

courtesy of MYV - San José

September 2011 DMT automatic acquisition

Editorial July 2010 Direct-push in situ tests : will they be the basis of our investigations ? Can direct-push replace lab? Notions emerged at CPT'10. Differences CPT - DMT.

Sand liquefaction based on DMT A recent KD-CRR correlation was obtained by Robertson in 2012. by replacing Qcn with 25 KD in the Robertson and Wride (1998) Qcn - CRR correlation. In 2006 Idriss and Boulanger (2006) updated the Robertson and Wride 1998 correlation - making it somewhat more conservative. By repeating the above mentioned substitution, i.e. replacing Qcn with 25 KD in the new consensus Idriss and Boulanger Qcn - CRR correlation, the following combination is obtained:
CRR = exp [(Qcn/540) + (Qcn/67)2 - (Qcn/80)3 + (Qcn/114)4 - 3] with Qcn =25 KD
The above equation is the today (2014) recommended correlation for predicting CRR based on KD.

Key References

(downloadable – see links below)

Dilatometer (DMT):

TC16 DMT Report by the ISSMGE (2001): a comprehensive document incorporating all the most important information
DMT Course Notes (2001) (Marchetti and Monaco): usable as a "User's manual" by DMT technicians. Procedure. Maintenance. Quality checks.

Seismic Dilatometer (SDMT):

Marchetti et al. (2008) Schmertmann Volume
Monaco et al. (2009) "Interrelationship ..", IS-Tokyo2009

Students: Schnaid's textbook "In Situ Testing" - Chapter 6 on DMT      

Manual DMT Briaud (1992) - US DOT Federal Highway Admin.

Content of 1-day Course on DMT and Seismic DMT (SDMT)

- Hardware, Working Principle, Procedure, Standards, Maintenance, Field equipment for running the test on land and offshore, testable soils.
- Using the results in the profession : Soil parameters, Settlements of shallow foundations and assessment of their accuracy by comparisons between observed and DMT-predicted settlements, Kh behind diaphragm walls from MDMT, Moduli before-after compaction, Moduli in roads subgrade, Laterally loaded piles, Detecting slip surfaces in slopes.
Seismic Dilatometer. Measurement of the shear wave velocity Vs, Combining the "low-strain" shear modulus Go with the "working strain" modulus Mdmt - both provided by SDMT - to help selecting the G-Gamma decay curves.
Liquefaction resistance evaluated by SDMT in two independent ways : from Vs and from KD.. Sensitivity of KD to aging, Importance of accounting for aging.
- Data reduction, presentation of results, diagrams, seismograms, Auto-Report generation.
- Troubleshooting, Quality controls, FAQ. Case-histories presented by invited experts.
- Participants will have the opportunity of executing a few measurements.

2nd International Conference on the Flat Dilatometer - Washington, D.C. April 2006
Index of the Conference papers
Proceedings and full Video of the Conference are available from R. Failmezger

Special Lectures at the Conference:
- John Schmertmann “How the Dilatometer moved the Cape Hatteras Lighthouse”
- Michele Jamiolkowski “Zelazny Most Tailings Pond: Site Characterization”
- Michele Maugeri “Liquefaction Potential Evaluation by SDMT”
- Silvano Marchetti “Summary of DMT Interpretation and Applications”
- Diego Marchetti “Software for handling combinedly Dilatometer and Seismic data”
- Failmezger R. (2006) "Thank you for attending the DMT 2006 Conference" (message)

Comparison between observed and DMT predicted modulus


  VIDEO (20 MB) by R. Failmezger

  VIDEO (70 MB) by N. Cruz

  Slide show on (S)DMT:  (824 KB),  (print version 2.6MB)

  Seismic DMT offshore (8 slides 2.9 MB)


  Photos DMT and SDMT   Test Layout   Machines for DMT Insertion
  Examples of Results   Settlement-Moduli Comparisons   Cu comparisons


  Interpretation Formulae   Database DMT sites in Italy   Soils testable by DMT
  Working principle animation   Software: update, download ...   Specifications (Engl   Ital)
  Dmt Users Community   Quality Certification   Bibliography
  Choice of Rig and Rods   Reading Hints   Field Data Sheets ( Engl   Ital )
  Compaction   Plaxis Parameters   Settlement Prediction
  Troubleshooting Hardware   Troubleshooting Interpretation   Troubleshooting


READING HINTS . For a general overview, see the following comprehensive documents:

Readers unfamiliar with DMT: Totani et al. 2001 Bali, 6 pages      (in Italian: Totani et al. 1999 Parma).

More detailed and extensive treatment : (a) In the form of paper : Marchetti 1997 Cairo and especially  TC16 2001 Bali.   
    (b) In the form of a series of slides: Marchetti 1999 Tokyo, Marchetti 2001 Torino.   (c) In the form of Course Notes - User's Manual: Course Notes 2001 Bali

Papers (of the above list) grouped by topic - all downlodable

Settlements and compressibility: Schmertmann 86, Lacasse 86, Leonards 88, Hayes 90, Iwasaki 91, Geopac 92, Jendeby 92, Woodward 93, Steiner 94, Tanaka 98, Failmezger 98-2000, Failmezger et al. 99, Pelnik et al.99, Schnaid et al 2000, Tice & Knott 2000

PMT and DMT : Schmertmann 87 Digest 9, Geopac 92, Kalteziotis 91, Lutenegger 88 and 90, Wong 93, Sawada 95, Ortigao 96, Schnaid 2000

Ch and K by DMT: Robertson 88, Schmertmann 88, Marchetti 89, Totani 98

Liquefaction: Marchetti 82, Robertson 86 , Reyna 91, Tanaka 98, Milestones on liquefaction 98, TC16 2001

For personal or educational non-commercial use only.

The documents *.pdf, require Acrobat Reader, freely downloadable at : http://www.adobe.com/products/acrobat/readstep.html

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