scholarly journals Analysation of the Effect of the Contact Properties on Soil’s Penetration Resistance in Discrete Element Simulations

2019 ◽  
Vol 12 (2) ◽  
pp. 148-160
Author(s):  
Krisztian Kotrocz ◽  
György Kerényi

Cone penetration in-situ tests are commonly used to measure the cone index of the soils. This measurement process can be modelled very well with Discrete Element Method (DEM) if the parameters of the correct contact model are defined properly. In this paper the Hertz-Mindlin with bonding contact model are used and the effect of the properties of this contact model on soil’s penetration resistance is investigated. Our aim was to determine those contact parameters which play important role in the penetration process, thus are necessary to take into account while calibrating the discrete element soil model to the results of real penetration tests.

2001 ◽  
Vol 38 (6) ◽  
pp. 1241-1253 ◽  
Author(s):  
Der-Her Lee ◽  
C Hsein Juang ◽  
Chi-Sheng Ku

This paper examines the liquefaction performance of soils at the site of a partially completed ground improvement project at the Chang-Hwa Coastal Industrial Park during the 1999 Chi-Chi earthquake in Taiwan. The site is on land reclaimed by hydraulic filling. To meet the need of a planned construction, site characterization was carried out with standard penetration tests (SPTs) and cone penetration tests (CPTs) at 13 locations. Dynamic compaction was later performed to mitigate the potential liquefaction hazards at this site. Before completion of the ground improvement work, the site experienced a major earthquake, the Chi-Chi earthquake (magnitude Mw = 7.6). Evidence of liquefaction was observed in this earthquake in the unimproved area but not in the improved area. After the earthquake, additional site exploration was carried out using SPTs and CPTs. The data from these in situ tests carried out before and after the earthquake and in areas with and without ground improvement are analyzed and the results are reported.Key words: ground improvement, in situ tests, liquefaction, earthquake.


2000 ◽  
Vol 37 (3) ◽  
pp. 505-529 ◽  
Author(s):  
C E (Fear) Wride ◽  
P K Robertson ◽  
K W Biggar ◽  
R G Campanella ◽  
B A Hofmann ◽  
...  

One of the primary objectives of the Canadian Liquefaction Experiment (CANLEX) project was to evaluate in situ testing techniques and existing interpretation methods as part of the overall goal to focus and coordinate Canadian geotechnical expertise on the topic of soil liquefaction. Six sites were selected by the CANLEX project in an attempt to characterize various deposits of loose sandy soil. The sites consisted of a variety of soil deposits, including hydraulically placed sand deposits associated with the oil sands industry, natural sand deposits in the Fraser River Delta, and hydraulically placed sand deposits associated with the hard-rock mining industry. At each site, a target zone was selected and various in situ tests were performed. These included standard penetration tests, cone penetration tests, seismic downhole cone penetration tests (giving shear wave velocity measurements), geophysical (gamma-gamma) logging, and pressuremeter testing. This paper describes the techniques used in the in situ testing program at each site and presents a summary and interpretation of the results.Key words: CANLEX, in situ testing, shear wave velocity, geophysical logging, pressuremeter.


Author(s):  
P. S. Finn ◽  
R. M. Nisbet ◽  
P. G. Hawkins

AbstractBS 5930 provides little guidance on the specification, practice and interpretation of pressuremeter, flat dilatometer and cone penetration tests. This paper describes certain key elements in the successful use of such tests which are frequently overlooked in practice. The different types of pressuremeter available in the United Kingdom are reviewed and the importance of care in the installation of pressuremeters of all types is highlighted. The principles of operation of the flat dilatometer are presented and comments made on the interpretation and application of results. Cone penetrometer testing and the types of equipment available are also discussed. The necessity for frequent and thorough calibration of all testing devices is emphasised and requirements for data presentation and reporting of these in situ tests are indicated.


2020 ◽  
Vol 205 ◽  
pp. 04005
Author(s):  
Philip J. Vardon ◽  
Joek Peuchen

A method of utilizing cone penetration tests (CPTs) is presented which gives continuous profiles of both the in situ thermal conductivity and volumetric heat capacity, along with the in situ temperature, for the upper tens of meters of the ground. Correlations from standard CPT results (cone resistance, sleeve friction and pore pressure) are utilized for both thermal conductivity and volumetric heat capacity for saturated soil. These, in conjunction with point-wise thermal conductivity and in situ temperature results using a Thermal CPT (T-CPT), allow accurate continuous profiles to be derived. The CPT-based method is shown via a field investigation supported by laboratory tests to give accurate and robust results.


Author(s):  
Meen-Wah Gui ◽  
Dong-Sheng Jeng

The application of cavity expansion theory in the back estimation of cone penetration tests conducted in calibration chambers has been carried out by many researchers. However, the theory is seldom employed by centrifuge modelers. Based on the work of spherical cavity expansion of previous researchers, this study proposed an analytical solution that incorporates the effects of cone geometry and surface roughness and the effect of compressibility to estimate the cone tip resistance. The calculated results are compared with the measured cone penetration resistance of four cone penetration tests performed in the centrifuge. The cone penetration tests were conducted in granular soil specimens having relative densities ranging between 54% and 89%. The comparison demonstrates the capacity of the cavity expansion theory in the prediction of the centrifuge cone penetration resistance.


2020 ◽  
Vol 57 (9) ◽  
pp. 1369-1387 ◽  
Author(s):  
A. Khosravi ◽  
A. Martinez ◽  
J.T. DeJong

This paper presents a study on the simulation of cone penetration tests (CPTs) using the discrete element model (DEM) method. This study’s main objective is to investigate the effect of different modeling parameters and simulation configurations on the ability of three-dimensional DEM simulations to replicate realistic CPT tip resistance (qc) and friction sleeve shear stress (fs) measurements. The CPT tests were simulated in virtual calibration chambers (VCCs) containing particles calibrated to model the behavior of sand. The parameters investigated included the granular assembly properties, interparticle contact parameters, particle–probe interface characteristics, and simulation configuration. Results indicate that the interparticle contact parameters, boundary conditions, and void ratio have an important role in the tip resistance and friction sleeve measurements obtained from the simulations. Particle-level interactions such as particle displacements and rotations and interparticle contact forces were analyzed throughout to provide insight into the differences in measured CPT response. Interpretation of the qc and fs measurements using soil behavior type (SBT) charts for soil classification indicates that the simulated CPT response is representative of the response of coarse-grained soils measured during field soundings. Analysis of results within the SBT framework can provide insight into the influence of soil particle properties on CPT-based soil classification.


1983 ◽  
Vol 20 (4) ◽  
pp. 734-745 ◽  
Author(s):  
P. K. Robertson ◽  
R. G. Campanella

This paper is the second of two parts and presents a summarized work guide for practicing engineers for interpretation of parameters for undrained conditions during the cone penetration test such as, undrained shear strength, overconsolidation ratio, and deformation characteristics of clay. The advantages, use, and interpretation of the piezometer cone are also discussed. Factors that influence the interpretations are discussed and guidelines provided. The companion paper, Part I: Sand, considers drained conditions during the test and summarizes interpretation of parameters such as relative density, friction angle, and deformation characteristics of sand. The authors' personal experiences and current recommendations are included. Keywords: static cone penetration testing, in-situ, interpretation, shear strength, modulus, stress history, pore pressures, permeability, consolidation.


2021 ◽  
pp. 106252
Author(s):  
Yongfeng Deng ◽  
Haochen Xue ◽  
Yongxin Wu ◽  
Tongwei Zhang ◽  
Zilong Wu ◽  
...  

Author(s):  
Nayyar Zia Siddiki ◽  
Athar Khan ◽  
Daehyeon Kim ◽  
Travis Cole

Since 1994, the Indiana Department of Transportation has constructed numerous recycled materials projects that use bottom ash, fly ash, foundry sand, crushed glass, and tire shreds in transportation facilities. All these projects were constructed in accordance with procedural specifications based on conventional compaction control tests such as the nuclear gauge. However, the nuclear gauge does not give accurate density and moisture content results because of the presence of numerous elements in recycled materials. In addition, sand cone tests are cumbersome and time-consuming. There is a need to develop criteria for in situ test methods such as the dynamic cone penetration test and lightweight deflectometer (LWD) testing. Once an initial criterion is established, criteria for compaction control of similar recycled materials can be developed. In a study, a test pad using coal ash was constructed with a combination of roller passes. On the basis of the results of dynamic cone penetration and LWD tests conducted in the test pad, in conjunction with a combination of roller passes, the criteria for compaction control of bottom ash was provided for the construction of the remaining 11-m-high embankment. The subsequent construction monitoring and postconstruction evaluation of the bottom ash embankment revealed that the criteria are very effective.


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