Traditional soil particle sphericity, roundness and surface roughness by computational geometry

Zheng, Junxing; Hryciw, Roman D.

doi:10.1680/geot.14.p.192

Cited by 319 publications

(117 citation statements)

References 43 publications

(58 reference statements)

Supporting

Mentioning

114

Contrasting

Order By: Relevance

“…The morphology of agglomerates in the slurry with PIBM was found to be more spherical than that in the slurry with PAANH 4 . The sphericity of particles (SP) was employed to evaluate the shape of agglomerates:

SP = \frac{D_{ins}}{D_{cir}},

where D ins is the diameter of the largest inscribing circle, and D cir is the diameter of the smallest circumscribing circle. Figure presents the statistical sphericity of 1600 agglomerates collected from the slurries with PIBM and PAANH 4 , respectively.…”

Section: Discussionmentioning

confidence: 99%

Density difference in pressure‐filtrated wet cakes produced from spontaneous gelling slurries

Shimai

Jian-Gao

et al. 2019

J Am Ceram Soc

View full text Add to dashboard Cite

Pressure filtration is a key process in ceramic forming; however, the influences of density difference in different parts of a pressure‐filtrated wet cake on subsequent drying and sintering have not yet been explored. In the present work, alumina slurries dispersed by copolymers of isobutylene and maleic anhydride (PIBM) and ammonium salt of polyacrylic acid (PAANH4) were pressure filtrated to examine the impacts of density difference in the as‐prepared wet cakes. In comparison to the wet cake produced from PAANH4, the wet cake with PIBM had much higher bulk density and smaller density difference between its upper and bottom parts (height of ~23 mm). Furthermore, in order to reveal the differences between these two wet cakes, the nature of agglomerates in their slurries was investigated. The slurry with PIBM contained agglomerates with a wider size distribution, bigger average size, and higher sphericity, producing a wet cake with a higher particle packing density and more homogeneous packing structure after pressure filtration. Hence, almost no deformation occurred in a large wet cake (280 mm × 130 mm × 20 mm) with PIBM, whereas that with PAANH4 experienced a severe deformation after sintering.

show abstract

SP = \frac{D_{ins}}{D_{cir}},

Section: Discussionmentioning

confidence: 99%

Density difference in pressure‐filtrated wet cakes produced from spontaneous gelling slurries

Shimai

Jian-Gao

et al. 2019

J Am Ceram Soc

View full text Add to dashboard Cite

show abstract

“…Sphericity is quantified as the radius ratio between the largest inscribed and the smallest circumscribing sphere. Regularity is the mean of roundness and sphericity (Krumbein & Sloss, 1963;Cho et al, 2006;Cavarretta et al, 2010;Zheng & Hryciw, 2015).…”

Section: Ae Measurement Systemmentioning

confidence: 99%

Early detection of first-time slope failures using acoustic emission measurements: large-scale physical modelling

2017

View full text Add to dashboard Cite

Early warning systems for slope instability need to alert users of accelerating slope deformation behaviour to enable safety-critical decisions to be made. This study shows that acoustic emission (AE) monitoring of active waveguides (i.e. a steel tube with a granular backfill surround installed through a slope) can both detect shear surface development and quantify increasing rates of movement during slope failure, thereby providing an early detection of slope instability. A large-scale physical model was designed and built to simulate slope failures on elements of soil, through which full-scale active waveguides were installed. A shear surface develops in each test and the sliding mass accelerates during failure, reaching velocities greater than 300 mm/h and shear deformations of 50 mm. Continuous measurements were obtained to examine the behaviour of active waveguides subjected to first-time slope failure dynamics (i.e. development of new shear surfaces and accelerating deformation behaviour). Comparisons with continuous subsurface deformation measurements show that AE detection began during shear surface formation, and AE rates increased proportionally with displacement rates as failure occurred. Empirical AE rate-slope velocity relationships are presented for three granular backfill types, which demonstrate that generic AE rate-slope velocity relationships can be obtained for groups of backfill types; these relationships allow displacement rates to be quantified from measured AE rates to provide early detection of slope instability.KEYWORDS: deformation; failure; field instrumentation; landslides; monitoring; slopes INTRODUCTION Shear surfaces can develop in slopes formed of strain-softening materials (e.g. overconsolidated clay) after very small deformations (millimetres) (Skempton, 1985;Bromhead, 2004). Shear zones develop when the shear stress exceeds the peak shear strength locally within the slope, causing reductions in strength to occur. These shear zones propagate through the slope, developing a continuous shear surface, leading to slope failure (Skempton, 1964;Skempton & Petley, 1967;Chandler, 1984;Leroueil, 2001). These first-time failures can have high post-failure velocities and experience large displacements, leading to potentially catastrophic consequences. During this failure process, the rate of movement increases by orders of magnitude; from the gradual development of a shear surface producing low velocities, to the high velocities that are reached after the shear surface forms, shear strength reduces and failure occurs. Early warning of this process (i.e. shear surface development and accelerating deformation behaviour) is critical to enable evacuation of vulnerable people and timely repair and maintenance of critical infrastructure.The Selborne cutting stability experiment (Cooper et al., 1998) provides a detailed example of a first-time failure. The progressive failure process began at the toe of the slope shortly after the cutting was formed, and the shear surface retrogressed up-slope le...

show abstract

“…The largest distance value and its location identify the radius and the center of the maximum inscribed sphere. The similar method was utilized by Zheng and Hryciw [14] to obtain the maximum inscribed circle from 2D particle outlines, whereas 3D algorithm was used in this study. Fig.…”

Section: Definition Of Particle Roundness Indexesmentioning

confidence: 99%

“…Recently, a novel method has been proposed to quantify roundness, a scale dependent variable, by fitting circles to the identified corners of a particle outline [14]. A more complex and theoretical method, Fourier mathematical method, has also been developed.…”

Section: Introductionmentioning

confidence: 99%

3D quantitative shape analysis on form, roundness, and compactness with μCT

2016

View full text Add to dashboard Cite

Particle shape plays an important role in determining the engineering behaviour of granular materials. In this regard, characterisation and quantification of particle shape are essential for understanding the behaviour of granular materials. X-ray micro-computed tomography (μCT) enables observation of particle morphology at ever-greater resolutions. The challenge has thus become extracting quantified shape parameters from these rich three-dimensional (3D) images. In this paper, we implement X-ray μCT to obtain 3D particle morphology and utilize image processing and analysis techniques to quantify it at different scales. A novel framework is proposed to measure 3D shape parameters of form, roundness, and compactness. New 3D roundness indexes were formulated from the local curvature on reconstructed triangular surface mesh. Subsequently, this method is utilized to study the change of particle shape by single particle crushing tests on Leighton Buzzard sand (LBS) particles. It is found that compactness value (i.e., sphericity) could be influenced by both form and roundness. Then, the distributions of shape parameters are characterised by Weibull statistics. It shows that single particle crushing tests generate more irregular fragments which have smaller shape parameters with larger variance for the measured shape parameters.

show abstract

Traditional soil particle sphericity, roundness and surface roughness by computational geometry

Cited by 319 publications

References 43 publications

Density difference in pressure‐filtrated wet cakes produced from spontaneous gelling slurries

Density difference in pressure‐filtrated wet cakes produced from spontaneous gelling slurries

Early detection of first-time slope failures using acoustic emission measurements: large-scale physical modelling

3D quantitative shape analysis on form, roundness, and compactness with μCT

Contact Info

Product

Resources

About