The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Vincent P. Drnevich - One of the best experts on this subject based on the ideXlab platform.
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A Study of Effective Soil Compaction Control of Granular Soils
2007Co-Authors: Vincent P. Drnevich, Aaron C. Evans, Adam Buser ProchaskaAbstract:Although it is known that impact Compaction tests are not appropriate for granular soils, these tests continue to be widely used. Excessive settlements frequently occur in granular soils where specified field Compaction is based on Standard Proctor (ASTM D 698; AASHTO T 99) maximum dry unit weights. A laboratory test program evaluated alternative test methods for granular soil Compaction Control and showed that a Vibrating Hammer method (similar to British Standard BS 1377:1975, Test 14) has great promise for laboratory Compaction of these soils. A One-Point Vibrating Hammer test on an oven-dry soil sample is able to provide the maximum dry unit weight and water content range for effective field Compaction of most granular soils. The maximum dry unit weight obtained is comparable to that from other current methods such as the Vibrating Table test (ASTM D 4253) and the Modified Proctor test (ASTM D 1557), and is greater than that from the Standard Proctor test (ASTM D 698). The method is applicable to a broader range of soils than current vibratory table Compaction tests (up to 35 percent non-plastic fines and up to 15 percent plastic fines). The equipment is relatively inexpensive and is portable enough to be taken into the field. The test is easier and quicker to perform than the other methods mentioned above and provides reproducible and consistent results. Large sized granular soils/aggregates create potential problems for Compaction Control methods due to the presence of oversize particles. Oversize particles defined here are those retained on a 3/4-inch (19-mm) sieve. INDOT Specification 202.34 (b) 2 requiring correction of densities from laboratory Compaction tests on soils with oversized particles is not being used in practice. It is not being followed primarily because guidance is not provided. As a result, the values of maximum dry unit weight from standard Compaction tests will be significantly lower than those corrected for oversized particles. This finding may be the biggest reason why granular fills with oversized particles are under- performing. The proposed Vibrating Hammer Method of Compaction specifically addresses the influence of oversize particles. Based on the results from this research, a draft ASTM Standard for the Vibrating Hammer Method of Compaction has been written, is well into the balloting process, and should become an ASTM Standard Method of Test in late 2007 or early 2008. It is included in Appendix A. This report also introduces a simple calibration procedure to verify that the vibrating hammer is supplying sufficient energy to the soil. The Vibrating Hammer Method of Compaction is an alternative method for specifying maximum dry unit weights for granular soils. The method also establishes a water content range for field Compaction. This research expands the applicable range of granular soils to those containing oversize particles. An experimental program, along with review of previous Compaction research, was carried out to determine the effect of oversize particles on Compaction performance. Testing was performed in two sizes of Compaction molds, 6-inch and 11-inch, in determining this effect. An oversize correction method was considered for water content and dry density when performing a test in a 6-inch mold with scalping, i.e. removal of oversize particles. Results of an INDOT pilot implementation project used to determine the viability of using the Vibrating Hammer for field Compaction are reported. Results indicate that the Vibrating Hammer method is sufficient for use with oversize particles and that maximum dry unit weights may occur at or near saturation.
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time domain reflectometry for Compaction Control of stabilized soils
Transportation Research Record, 2004Co-Authors: Vincent P. DrnevichAbstract:Chemical stabilization is widely used in geotechnical engineering to improve the engineering properties of geomaterials. The interaction between the stabilizers and soil particles changes the physicochemical structure of these materials and increases their performance. Water content and density are the indicators used in field practice for construction quality Control of the stabilized soils. The nuclear method is currently the preferred technology for field measurement of water content and dry density in geotechnical engineering. However, the nuclear method has been found to give inaccurate results when used on stabilized soils. Researchers at Purdue University developed a procedure to measure soil water content and dry density using time domain reflectometry (TDR). Tests performed on conventional soils indicate that this procedure is accurate and fast. The feasibility of this technology on the stabilized soils was investigated; the preliminary conclusion was that TDR achieves satisfactory accuracy. In a...
Michael A. Mooney - One of the best experts on this subject based on the ideXlab platform.
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anisotropy in the spatial distribution of roller measured soil stiffness
International Journal of Geomechanics, 2010Co-Authors: Norma W Facas, Reinhard Furre, Michael A. MooneyAbstract:The geostatistical analysis of roller-measured soil properties (from continuous Compaction Control and intelligent Compaction) is required for advanced quality Control/quality assurance of earthwork and asphalt Compaction. This paper explores the existence of anisotropy in the spatial distribution of roller-measured soil stiffness and the effect of anisotropy on kriging. Field testing was conducted to collect roller measurement value (MV) data over typical roadway embankment evaluation areas and on a large square area to enable a robust investigation of anisotropy. The semivariogram analysis of the field data clearly indicates that range anisotropy exists. The spatial distributions of roller MV data are different in the longitudinal x -direction than in the transverse y -direction. Magnitudes of range anisotropy ( x-range/y-range ) varied from 2.4 to over 5. The observed range anisotropy is not due to the roller measurement system; rather, it is likely due to the directional nature of earthwork constructi...
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comparison of stress states and paths vibratory roller measured soil stiffness and resilient modulus testing
Transportation Research Record, 2009Co-Authors: Robert V Rinehart, J R Berger, Michael A. MooneyAbstract:Vibratory roller-based measurement of soil stiffness during intelligent Compaction and continuous Compaction Control can be used for performance-based quality assurance of unbound materials. To realize this potential, the relationship between the roller-measured soil stiffness and the soil modulus, particularly resilient modulus, must be understood. The in situ stress states and paths experienced by soil beneath a vibratory roller were compared with stress states and paths during laboratory resilient modulus testing. Observed stress fields within the 1-m depth of influence varied considerably for both vertically homogeneous embankment soil and layered base over subgrade conditions. During low excitation force vibration, roller-induced levels of deviator stress were notably greater than those used during laboratory resilient modulus testing, whereas levels of mean stress were less. Predicted modulus variation with depth was strongly influenced by modulus function parameters. With typical granular soil parameters, modulus was found to be constant with depth for the embankment conditions. With modulus parameters of more fine-grained behavior, modulus increased considerably with depth.
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vibratory roller integrated measurement of earthwork Compaction an overview
Seventh International Symposium on Field Measurements in Geomechanics, 2007Co-Authors: Michael A. Mooney, Dietmar AdamAbstract:This paper provides a state of the art overview of vibration based measurement systems used on vibratory roller compactors to continuously measure soil properties during and after earthwork Compaction. The European community initiated the development of roller integrated measurement and continuous Compaction Control (CCC) over 30 years ago. Roller measurement values have since evolved towards the estimation of more mechanistic soil parameters, e.g., stiffness, modulus. Independent assessment of these measurement values has proven their efficacy.
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surface wave testing to investigate the nature of roller determined soil stiffness
20th EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, 2007Co-Authors: Nils Ryde, Michael A. MooneyAbstract:Continuous Compaction Control (CCC) with instrumented vibratory roller compactors is an effective tool to estimate the relative soil stiffness over the complete area of a construction site. However, research is still needed to extract roller measured stiffness values directly comparable with pavement design parameters and laboratory measurements. In this study we have used surface wave testing over a compacted subgrade along with CCC to study the influence depth of the roller measured stiffness value. Results show that shear wave velocity with depth profiles can be useful to study the influence depth of roller measured stiffness values.
Dietmar Adam - One of the best experts on this subject based on the ideXlab platform.
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fundamentals of roller integrated Compaction Control for oscillatory rollers and comparison with conventional testing methods
Transportation geotechnics, 2018Co-Authors: Johannes Pistrol, Dietmar AdamAbstract:Abstract Oscillatory rollers are used for Compaction work in sensitive areas like inner city construction sites or near vibration-sensitive structures due to their ability to cause very low ambient vibrations. The fundamentals of oscillatory roller Compaction and Continuous Compaction Control (CCC) with oscillatory rollers are discussed within the present paper. The influence of the soil stiffness on the motion behaviour of an oscillatory drum was studied to introduce a novel CCC value for oscillatory rollers based on these findings. The algorithm for the calculation of this novel CCC value for oscillatory rollers is tested on real acceleration measurements obtained from experimental field tests. Moreover, the CCC value is extensively compared to the results of dynamic load plate test by means of the Light Falling Weight Device and to the results of CCC measurements with vibratory rollers.
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continuous Compaction Control ccc with oscillating rollers
Procedia Engineering, 2016Co-Authors: Johannes Pistrol, Sebastian Villwock, Werner Volkel, Fritz Kopf, Dietmar AdamAbstract:Abstract CCC systems are the state of the art method for an assessment of the achieved Compaction success with vibratory rollers. However, CCC systems were not available for oscillatory rollers, which differ from vibratory rollers not only in their construction, but also in their motion behaviour and way of dynamically loading the soil. Experimental field tests were performed to analyse the motion behaviour of an oscillatory drum and a CCC value for oscillating rollers is presented based on empirical observations and a semi-analytical modelling of the drum-soil interaction. Moreover, the algorithm of the CCC value is tested on measurement data of the experimental field tests and the influence of weak spots on the CCC values is investigated.
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vibratory roller integrated measurement of earthwork Compaction an overview
Seventh International Symposium on Field Measurements in Geomechanics, 2007Co-Authors: Michael A. Mooney, Dietmar AdamAbstract:This paper provides a state of the art overview of vibration based measurement systems used on vibratory roller compactors to continuously measure soil properties during and after earthwork Compaction. The European community initiated the development of roller integrated measurement and continuous Compaction Control (CCC) over 30 years ago. Roller measurement values have since evolved towards the estimation of more mechanistic soil parameters, e.g., stiffness, modulus. Independent assessment of these measurement values has proven their efficacy.
Rolf Becker - One of the best experts on this subject based on the ideXlab platform.
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use of time domain reflectometry to estimate moisture and density of unbound road materials laboratory calibration and field investigation
Transportation Research Record, 2017Co-Authors: Habibullah Bhuyan, Alexander Scheuermann, Didier Bodin, Rolf BeckerAbstract:Soil moisture content and dry density of unbound granular pavement materials are important properties for Compaction Control that influence pavement performance under cyclic loading. Under these loading conditions, increasing moisture content can accelerate significant changes in density. Time domain reflectometry (TDR) is a method for measuring the moisture content and density of soils with rod probe sensors. This paper introduces new calibration functions for TDR measurements using these rod probe sensors embedded in the soil. TDR measurements were taken in the laboratory for a typical road base material at two basically different conditions: at constant moisture content with different dry densities and at constant dry density with different moisture contents. In this study, a relationship was developed between the voltage drop occurring for the passage of an electromagnetic wave through the soil and the bulk density. The permittivity of the soil sample obtained from the travel time of TDR signals was u...
I. Paulmichl - One of the best experts on this subject based on the ideXlab platform.
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Heavy tamping integrated dynamic Compaction Control
Proceedings of the Institution of Civil Engineers - Ground Improvement, 2007Co-Authors: D Adam, H Brandl, F Kopf, I. PaulmichlAbstract:Heavy tamping is a deep dynamic Compaction technique and has been increasingly used since the beginning of the 1970s. The present paper reports on in situ measurements and theoretical investigations referring to the decay of free soil vibrations caused by the falling weight after each impact. This behaviour is significant for the respective soil—falling mass interaction and enables a site-specific optimisation of the heavy tamping technique. The field tests comprised acceleration measurements of the falling mass and the soil whereby the falling height was changed repeatedly. The decay of the amplitudes of free vibrations provided a damping coefficient and a damped natural frequency, which are used to determine the Poisson's ratio and the E-modulus of the ground after each impact from numerical calculations. The scope of the research project was to gain a reliable indicator for the degree of Compaction of the soil immediately after each impact, and hence obtain a method for Compaction Control and documenta...
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untersuchungen des statischen lastplattenversuches mit der randelementmethode test results obtained by the static load plate test using the boundary element method
OESTERREICHISCHE INGENIEUR- UND ARCHITEKTENZEITSCHRIFT OEIAZ, 2005Co-Authors: F Kopf, C Adam, I. PaulmichlAbstract:Fuer die Untersuchung des statischen Lastplattenversuches wird in der Arbeit der Versuch mit der Randelementmethode numerisch modelliert. Dabei wird der Untergrund als linear elastischer Halbraum mit aufliegender Deckschicht beschrieben. Auf der Grundlage von umfangreichen Parameterstudien wird der Einfluss lageweise unterschiedlicher Bodenparameter bei der Verdichtungskontrolle von Erdbauwerken mit der statischen Lastplatte bewertet. Die Auswirkungen von unterschiedlichen Messvorrichtungen, wie Dreiuhren- und Einuhrmessgeraet, und Lastumlagerungen bei der Kraftaufbringung auf die Messtiefe werden quantifiziert und eingehend diskutiert. Die Unterschiede zwischen der praktischen Versuchsdurchfuehrung und den theoretischen Annahmen fuer die Versuchsauswertung werden aufgezeigt. ABSTRACT IN ENGLISH: In the paper the reliability and quality of test results obtained by the static load plate test are analyzed by means of computer simulation utilizing the Boundary Element Method. In the numerical model of the subsoil an elastic layer is placed on an elastic halfspace. Based on extensive parameter studies the influence of layerwise varying soil properties on the Compaction Control is evaluated. The effects of different measurement equipments, such as the device with three gauges and the device with only one gauge, and load redistribution during application of the force on the measuring depth are quantified and discussed in detail. Differences between the practical test implementation in the field and simplified assumptions for the test evaluation are identified. (A)