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Hungarian experience about the correlation of CPT and DPH results is summarized. A historical review of CPT-DPH and CPT-SPT correlations is presented, and the reliability of the published CPT-DPH correlations is analyzed using recent data from Hungarian geotechnical practice. Based on these data the paper defines soil types where reliable correlati...
Citations
... CPTu static sounding and DPH dynamic probing are widely used to assess the geotechnical parameters of the subsoil [1][2][3][4][5][6][7][8][9][10][11]. These two methods differ significantly in the way of penetration of the cone, the required equipment, measured parameters and interpretation possibilities [12][13][14]. ...
... where: D 30 -size of the particle corresponding to 30% finer The distribution of the above parameters based on 78 samples is shown in the histograms below (Figs. [6][7][8]. ...
This paper attempts to relate the parameters obtained from CPTu static sounding and DPH dynamic test conducted in non-cohesive alluvial deposits of the Vistula River. The investigation was carried out in eight test stations located on the left bank of the Vistula River in Warsaw. The presented theses were based on the results of static CPTU and dynamic DPH tests obtained at 8 test stations. Additionally, in order to associate the obtained sounding results to the lithological type of the tested medium, drillings and grain size analyses were performed. The correlation of the different test methods stems from the need to identify and explain observed discrepancies against the background of different geological conditions, such as moisture content or grain size distribution. The comparative analysis of the parameters obtained from static and dynamic probing, is relevant to the alluvial sediments formed the lower over-flood terrace (called “the Praski terrace”) of Warsaw. Based on the comparison this paper proposes a correlation between the cone penetration resistance the sleeve friction and the number of blows, expressed by the functional relationship. Differences in the matching formulas were shown depending on the saturation of the tested sediments. Correlations were referred to a soil type, which enabled to specify the range of applicability of the proposed relationships. The results of the study were further used to show their diversity using statistical methods. This made it possible to assess the variability of the parameters of the non-cohesive soil, which forms a single lithogenetic unit.
... When executing DPH and DPM a falling weight equal to 50 and 30 kg is used respectively (DIN EN ISO 22476-2 2013). In practical engineering, the density is often evaluated based on blow counts in non-cohesive soils (Bagińska 2020;Czaczkowski et al. 2015;Mahler and Szendefy 2009). ...
The compaction control of earth works is an essential task in geotechnical engineering. In order to build more sustainably and to reduce project costs, fine-grained materials are more often used for embankment construction nowadays. The quality control of compacted soil layers is usually defined in terms of deformation moduli obtained from static and dynamic plate load tests or based on the degree of compaction, which is generally related to the Proctor density. Penetration tests, such as cone penetration tests (CPT), seismic flat dilatometer tests (SDMT) or dynamic probings (medium heavy dynamic probings (DPM)), show a potential for assessing the compaction along vertical profiles but no standardized quality criteria have been elaborated yet. The present work investigates the effects of different water contents and degrees of soil stabilization on results of CPT, SDMT, DPM, plate load tests and Proctor tests for an 8 m high trial embankment, characterized by a clayey to silty material. CPT and DMT results were found to strongly correlate with deformation moduli of static and dynamic plate load tests, enabling the definition of new quality criteria for compaction control.
... As far as the authors are aware, little research has been carried out into the dependence of the penetration resistance of dynamic probing in sandy gravels with D 50 around 2-10 mm as present in Dike A21 (e.g., Melzer [24] examined sands with a maximum D 50 of 4 mm and Biedermann [2] does not provided relationships for gravels). A newer study investigating the correlation between CPT and DPH results by Mahler and Szendefy [22] (who investigated soils with a D 50 of up to 10 mm) suggests that such correlations can be applied up to d p / D 50 & 5, with a larger scattering being observed for D 50 [ 2 mm. Furthermore, the work by Karray and Hussien [16] which synthesized a number of studies comparing the cone penetration resistance obtained from the CPT with shear wave velocities indicates an increase in the fluctuation with increasing mean grain size. ...
... Several interpretation models for DPH test results can be found in the literature, one of which is the empirical correlation from Kralik [18] between the cone penetration resistance, q c (in MPa), and the number of blow counts for 20 cm penetration, N 20 , which simplifies to: Mahler and Szendefy [22] proposed a relationship based on a normalized CPT-DPH ratio, taking into consideration the mean grain size and the vertical stress, with after considering an average grain size of the inner core of 10 mm, treatment depth of 12 m and buoyant unit weight of c 0 ¼ 10:6 kN=m 3 the following relationship can be obtained: ...
This article presents an interpretation and statistical analysis of heavy dynamic probing (DPH) tests carried out on the compacted core of Dike A21, of the Diavik Diamond Mine. Due to the inhomogeneous and inherently random nature of soil and the uncertainties associated with even well controlled field tests such as DPH tests, the evaluation of in situ properties (such as density) should take into consideration the natural variability of the soil. Aided by the large amount of relatively concentrated field data, this paper presents a methodology for not only evaluating the field tests statistically through Kriging, but also for judging the compaction effort, taking into consideration the variability. This paper documents the necessary normalization procedure, analyzing a number of external factors such as the temperature, time since compaction (aging) and the presence of nearby works that may affect the field data. It was shown that the appraisal of soil improvement measures should consider the presence of natural and unavoidable fluctuations of the fill material. The Kriging estimate combined with an averaging procedure and subsequent comparison with the expected variability, quantified by the variogram, was applied which enabled the assessment of areas with insufficient compaction. Additionally, the influence of aging of the fill was demonstrated, where a clear increase in the DPH tests between 0 and 14 days since compaction was observed. It was also found that over-compaction leads typically to a lower relative density. The authors note that this statistical analysis was performed following the control and acceptance of the compaction of the dike and as such had no impact on the acceptance of the dike construction.
... It remains to be verified whether the findings of Salgado & Prezzi [29] regarding the influence of the shape of the cone tip can be extrapolated to gravelly soils. In this respect, Mahler & Szendefy [51] found the ratio between q c and N 10 to be generally influenced by grain size. However, for gravelly soils, no definitive conclusion could be drawn due to the high variation of their data. ...
Despite the widespread availability and superior information provided by the cone penetration test (CPT), dynamic probes like the DPH (dynamic probe heavy) remain an important soil investigation method under certain circumstances. In order to make use of the results of the DPH in the context of the vast body of interpretation and design methods developed for CPT tests, the drop count N 10 of the DPH is correlated to the tip resistance q c of the CPT. There are numerous correlations between both values available in the standards and in the literature. However, any soil‐related differences, limitations, and factors influencing those correlations are not necessarily obvious. The present paper presents a simple framework for the illustration of influencing factors and the interpretation of correlations between DPH and CPT. The proposed framework is based on the information provided in EN ISO 22476‐1 and published scientific literature. Linear correlation factors based on the proposed framework are derived. These factors are then compared with our own field data and information from the literature.
... Therefore, it seems important to search for new correlations established for various local conditions and various non-cohesive soils (Czado and Pietras 2012;Lingwanda et al. 2015;Kodicherla and Nandyala 2016;dos Santos and Bicalho 2017). Research should also include finding the relationship between CPTu measurements and various dynamic probing techniques (Dynamic Penetrometer Light, Medium, super Heavy), as well as SPT (Standard Penetration Test) results, as indicated by Gadeikis et al. (2010); Pinheiro et al. (2018) and Ampadu et al. (2018) for non-cohesion soils and by Mahler & Szendefy (2009) for cohesive soils. ...
This paper presents a comparison of geotechnical soil testing with the use of Piezocone Penetration Test (CPTu) and Dynamic Probing Heavy (DPH) in a uniform coarse-grained medium located in southwest part of Poland. The soil medium was identified in detail. The interpretation of results included both grain-size analysis of samples from drillholes and soil behavior type results obtained from the Robertson nomograph (Soil behaviour type from the CPT: an update. In: 2nd international symposium on cone penetration testing, USA, 2010). Cone penetration resistances qc obtained in the static CPTu tests were compared with the results of dynamic probing N10H and of dynamic point resistance qd obtained in the dynamic DPH tests. The evaluation of soil density index was based on both dynamic DPH and static CPTu probing. The obtained results were analyzed and plotted in a form of graphs corresponding to the Eurocode 7 and other works describing coarse-grained soils.
... Korrelationen zwischen CPT und DPL an einem Standort aus tonigem bis schluffigem Sand werden in [28] entwickelt; eine geringfügige Verbesserung ergibt sich, wenn auch die lokale Mantelreibung einbezogen wird. Beziehungen zwischen CPT und DPH in [29] werden in Abhängigkeit vom mittleren Korndurchmesser angegeben und berücksichtigen a priori den Einfluss des Überlagerungsdrucks. Vergleiche von SPT-mit DPSH-Schlagzahlen für Sande und schluffige Sande sind in [30] angegeben. In [7] werden schließlich auch Beziehungen für die elek trische Maihak-CPT-Sonde q cM und die niederländische CPT q c vorgeschlagen. ...
... Bild 2. Ergebnisse aus Versuchen in Kalibrierungskammern in [8] und [52] und aus ungestörten Proben in [51] sowie Ausgleichskurve nach Gl. (26) mit zugehörigem 95-%-Vertrauensintervall Fig. 2. Results from calibration chamber tests [8] [52] and from undisturbed samples [51], and approximation curve according to eq. (26) with the corresponding 95 % confidence interval Bild 3. Auswertung der Versuchsdaten in [7] für die beiden Drucksonden zusammen mit der Regressionskurve nach Gl. (29) Fig. 3. Evaluation of the experimental data in [7] ...
... Eine Gegenüberstellung der empirischen Gl. (26), (27) und (29) findet sich in Bild 4. Man erkennt daraus, dass alle drei empirischen Beziehungen bei q c1N = 100 zusammenfallen mit einem Wert I D = 0,55. Es sollte hervorgehoben werden, dass die druckabhängige Normierung bei allen Gleichungen über Gl. (8) mit Begrenzung nach Gl. (9) erfolgte. ...
Der Einsatz von Rammsonden zur Abschätzung der Lagerungsdichte von nichtbindigen Böden ist in Deutschland sehr verbreitet. Die zugehörigen empirischen Korrelationen aus der inzwischen zurückgezogenen DIN 4094‐3 wurden teils in die DIN EN 1997‐2 und teils in die DIN 4094‐2 übernommen. Die Abhängigkeit der Schlagzahl von der Tiefe und somit vom Spannungsniveau wird dabei nicht explizit berücksichtigt und es wird lediglich zwischen Situationen über und im Grundwasser unterschieden. Der Einfluss des Überlagerungsdrucks wird auch bei den Drucksondierungen nicht berücksichtigt. Bedingt durch die verfeinerte Instrumentierung und die damit verbundene Möglichkeit einer differenzierteren Charakterisierung des Baugrunds gewinnen Drucksondierungen zunehmend an Bedeutung, so dass für diesen Sondierungstyp der Fundus von Korrelationen in der internationalen Fachliteratur groß ist. Im Rahmen einer Vergleichsuntersuchung werden die Anwendungsgrenzen und die Zuverlässigkeit der in den Regelwerken vorgeschlagenen empirischen Beziehungen kritisch bewertet und durch neue Ansätze erweitert. Besonderes Augenmerk wird dabei auf Korrelationen zwischen den Ergebnissen der beiden Sondierungstypen gelegt.
... intact Kiscelli Clay) [3], CPT is more applicable to calculate pile bearing capacity with additional in-situ test (e.g. dynamic probing) [4]. In this study, the profiles of the stress history were analysed by triaxial and oedometer test results. ...
... Results, e.g. void ratio,-moisture content,-shear strength,-major stress at failure,-oedometer,unloading-reloading modulus,-overconsolidation ratio as functions of depth were already analysed previously [3][4][5][6]. The fundamental idea for the present article was provided by the research result associated with Fig. 2, where preconsolidation stress evaluation from small-strain shear modulus was analysed by [7]. ...
The study is about the estimation of preconsolidation stress using a correlation method. Disturbance of soil samples can result in the yield point of void ratio-log vertical stress data from oedometer test being unreadable. Therefore, correlations were calculated to estimate preconsolidation stress using effective vertical stress (Formula Presented), oedometer modulus (Eoed) from oedometer tests and unloading-reloading modulus (Eur) from triaxial tests. Profile of stress history: Overconsolidation ratio (OCR), overconsolidation difference (OCD) and overconsolidation gradient (OCG) were determined in Kiscelli Clay based on new equations. An additional new parameter, ratio of mechanical preloading component of overconsolidation is defined and analysed.
... It is possible to determine the value of preliminary loading with the use of oedometer tests in the course of laboratory investigations and in-situ tests on the site although it is not possible to establish further soil-or rock-mechanical properties of an overconsolidated layer. [8,10,11] The optimum method to determine vertical and horizontal stresses is the use of local, in-situ investigations since these measurements have the least disturbing effects on the original stress conditions of a soil layer under test. ...
The study is about the general genesis process of overconsolidated soils, as well as the effects of the overconsolidated ratio to structures. It will demonstrate the possible methods for the determination of the values of overconsolidated ratio and of earth pressure at rest and of the other soil-physical parameters; further, the processing of measurement results, through which the values of OCR (Overconsolidated ratio) and of λ0 (Earth pressure at rest) and of c, E soil-physical parameters (friction angles, cohesion and Young modulus) in the Kiscelli Clay Marl have been determined by Selfboring Pressuremeter.
... The best method to determine horizontal and vertical stresses is the use of local, in-situ investigations because these measurements have the least disturbing effects on the original stress conditions of a soil layer under test. The behaviour of the soils is determined by CPTu which is one of the world-wide best-known in-situ measurements [6] but horizontal earth pressure can be determined in indirect way. Three different in-site investigations have been performed in order to determine the overconsolidated ratio and the earth pressure at rest: measurement with an earth-pressure cell; measurement with a borehole cell; and a measurement with a selfboring pressuremeter. ...
The study is about the general genesis process of overconsolidated soils, as well as the effects of the overconsolidated ratio to structures. It will demonstrate the possible methods for the determination of the values of overconsolidated ratio and of earth pressure at rest; further, the processing of measurement results, through which the values of OCR (Overconsolidated ratio) and of λ 0 (Earth pressure at rest) in the Kiscelli Clay Marl have been determined.
In Tanzania, standard penetration test (SPT) is the most commonly used in situ test for foundation design site investigations. In an effort to increase the amount of geotechnical information at low cost, the quicker and much cheaper dynamic probing of light (DPL) hammer is sometimes performed along with SPT to supplement the expensive SPT. Nevertheless, the information gathered with DPL has been applicable only for site stratification. Recently, the static cone penetration test (CPT) has also been introduced in the country with a view to combining these methods in site investigations. In this study, side by side testing was performed with the three in situ methods and correlations established through regression analysis and arithmetic mean methods. Results indicate that DPL data correlate better with CPT than SPT data, with lower magnitudes of transformation uncertainty. The local SPT-CPT correlations compare fairly well to those in the literature. The established correlations extend the function of DPL data to analysis and design.
