Dilatometry is a thermoanalytical method for measuring the shrinkage or expansion of materials over a controlled temperature regime. The flat dilatometer astm 6635 was developed by dr. It is a relatively simple test and its use in geotechnical investigations becomes. Gabr abstract changes in the lateral stress condition in soil in the immediate vicinity of the blade of the flat dilatometer during the penetration of the device were ex perimentally investigated in a laboratory study. We were the organizers of the second international conference on the flat dilatometer test 2006. Flat plate dilatometer and koblade correlations in the coastal plain in delaware. The amount of expansion or shrinkage is dependent on the characteristics of. Pdf in situ tests by flat dilatometer researchgate. Once the test depth is reached, a circular steel membrane located on one side of the blade is expanded horizontally into the soil, the operator records two pressures a. Guide to insitu testing 2006 glossary i glossary this glossary contains the most commonly used terms related to cpt and are presented in alphabetical order. A dilatometer test consists of pushing a flat blade located at the end of a series of rods. In the last decades there has been a massive migration from laboratory testing to in situ testing, to the point that, today, in situ testing is often the major part of a geotechnical investigation.
With continued refinement of empirical correlations and worldwide acceptance, the dmt test continues to be used on some of the most significant engineering projects in the world. Proceedings of the first international conference on the flat. Pdf this report presents an overview of the dmt equipment, testing procedure, interpretation and design applications. The blade is jacked into the ground and at 20 cm depth intervals the jacking is stopped and the membrane is inflated by means of pressurized gas.
For applications requiring lower or higher temperatures vertical arrange ment ist better suited vertical arrangement zero friction design sample is only in contact with the end knob and the pushrod. The flat dilatometer dmtin situ test is an for the determination of various key soil parameters used for geotechnical design. Flat dilatometer test and its applications in geotechnical. The test is rapid, accurate, simple and costeffective. Dilatometry is a method for characterizing dimensional changes of a material as a function of temperature. Design, use and interpretation of an instrumented dilatometer test. With a dilatometer, test samples are quickly and easily measured for determining firing ranges and. When at rest, the external surface of the membrane is flush with the surrounding flat surface of the blade. A dilatometer capable of meeting the requirements is described in the journal of scienti. Introduction video on the use of the marchetti dilatometer. Dilatometry dil l76 dil l75 horizontal dil l75 vertical. The flat dilatometer test dmt was developed in italy by silvano marchetti.
Totani and schedar marchetti and paola monaco and marcello calabrese, year2000. Use of the flat dilatometer test dmt in geotechnical design. Each test consists of an increment of penetration, generally vertical, followed by the expansion of a flat, circular, metallic membrane into the surrounding soil. To assure high quality control, all dilatometer tests are performed by a registered professional engineer. The wide diffusion of the dmt lies on the following reasons lutenegger 1988. Marchetti flat dilatometer dmt sdmt test marcoisin. Dmt test results may be used to obtain information about the stratigraphy of the subsoil, stress condition, deformation properties and shear strength. A flat blade shaped tip, with a thin flat circular steel membrane fitted flush with one side, is jacked into the ground. The flat dilatometer insitu testing device dmt has been used frequently north america and europe during the short period of time since its introduction. Seismic dilatometer test sdmt sdmt is a combination of the standard flat dilatometer dmt with a seismic module. The flat dilatometer test dmt in soil investigations a report by the issmge committee tc16 marchetti s. Pdf use of the flat dilatometer test dmt in geotechnical.
Flat dilatometer test dmt the dmt consists of a stainless steel blade with a thin flat circular expandable steel membrane on one side. The marchetti dilatometer dmt consists of a flat steel blade having a thin, expandable, circular steel membrane mounted on its surface. It consists of a 240 mm long, 95 mm wide and 15 mm thick stainless. The flat dilatometer test dmt in soil investigations. The seismic module is a tubular element placed above the dmt blade, equipped with two receivers located 0. In brief, the flat dilatometer consists of a stainless steel blade with a thin flat circular expandable steel membrane on one side. Applications and recent developments diego marchetti.
Because the flat dilatometer testing process is new, we have been very curious to see how well it can predict actual soil behaviour. This method involves a stainless blade shaped probe with a thin circular steel membrane mounted on one side. The flat dilatometer test dmt is an insitu testing method used to determine the strength and deformation characteristics of finegrained soils. Cone penetration test video cone cpt module viewing coal tar demonstration vertek ara duration.
The use of dilatometer test for the determination of undrained shear strength in organic soils. This paper presents an interpretation of the flat dilatometer test in clay based on simplified theoretical solutions of cavity expansion in modified cam clay. The flat plate dilatometer dmt sdmt has proven to be an essential insitu test for many geotechnical applications. Note this document fulfils the requirements for flat dilatometer tests as part of the geotechnical investigation and. Pdf the flat dilatometer test dmt in soil investigations a. In engineering practice the empirical correlations or charts are often use to determine soil. The pressure is recorded at three specific moments during the test. This paper presents an overview of the dmt and of its design applications, in the light of the experience accumulated over the last 20 years. Design applications silvano marchetti faculty of engineering, laquila university, italy bsmci since the writers 1980 asce paper marchetti, 1980. Pdf on jan 1, 2001, s marchetti and others published the flat dilatometer test dmt in soil investigations find, read and cite all the. Marchetti dilatometer test to soft ground in japan, geocoast 91, sept. Flat dilatometer test dmt 77 pressuremeter test pmt 80 main references 86. Marchetti dilatometer test or flat dilatometer, commonly designated by dmt, was created by silvano marchetti 1980 and is one of the most versatile tools for soil characterization, namely loose to medium compacted granular soils and soft to medium clays, or even stiffer if a good reaction system is provided. Effects of test procedure on flat dilatometer test dmt.
Proceeding from the second international conference on the flat. Pdf sand liquefiability assessment by flat dilatometer. It was initially introduced in north america and europe in 1980 and is currently used in over 40 countries. A dilatometer test dmt consists of pushing flat blade into the soil, to a desired depth using a cpt rig. Cptu cone penetration test with pore pressure measurement piezocone test. The results are highly repeatable and independent from the operator. The blade has a cutting edge to penetrate the soil and is inserted into the ground at the desired depth. These conditions rule out the use of most pushrod type dilatometers. Dilatometry can be used to test a wide range of material including traditional and advanced ceramics, glasses, metals, and polymers. The flat plate dilatometer dmt is an insitu test device with specific advantages that can useful on certain projects. From a corrected first reading p 0 and a corrected second reading p 1 one can calculate soil parameters such as. The flat dilatometer, or dmt, is an insitu device used to determine the soil insitu lateral stress and soil lateral stiffness and to estimate some other engineering properties of subsurface soils. The flat dilatometer test dmt, in troduced by mar chetti 1980, is increasingly use d in the last years, als o stimulated by the diffusion of its efficient allinone. The test is initiated by forcing the steel, flat plate, dilatometer blade 2, with its sharp cutting edge, into a soil.
This report presents an overview of the dmt equipment, testing procedure, interpretation and design applications. The evaluation of rate effects on the flat dilatometer test dmt can best be developed with some knowledge of the excess pore pressures generated during penetration, dissipation, and subsequent membrane expansion. The flat dilatometer test dmt, developed in italy in 1980, is currently used in over 40 countries both for research and practical applications. Pdf the use of dilatometer test for the determination of. The test is initiated by forcing the steel, flat plate, dilatometer blade, with its sharp cutting edge, into a soil.
Table 1 from use of the flat dilatometer test dmt in. A dilatometer is a precision instrument for the measurement of dimensional changes in material as a function of temperature. However, it is not yet used as frequently as the cone penetration test cpt in engineering practice. This report presents an overview of the dmt equipment. The pressure is recorded at specific moments during the test. Orton dilatometers can be used to determine coefficient of thermal expansion cte, softening point, glass transition temperature, curie point, crystalline transformation, phase transition, shrinkage, warping, bloating, sintering rate, isothermal creep, and stress relaxation.
780 648 595 562 1286 781 599 749 1405 733 638 1632 23 928 266 827 1547 324 525 1040 1354 1088 831 1024 434 321 1279 428 751 458 500 1297 894 111 156 1284 750 1023 202 10 1361 1008