Cyclic Threshold Shear Strains in Soils

Vučetić, Mladen

doi:10.1061/(asce)0733-9410(1994)120:12(2208)

Cited by 414 publications

(245 citation statements)

References 19 publications

Supporting

Mentioning

197

Contrasting

Unclassified

Order By: Relevance

“…Following each stage of cyclic shearing, drainage valves were opened, and post-cyclic deformations and volume changes were monitored for variable time intervals, as indicated in Table 1. Strain-controlled tests were preferred instead of stress controlled tests because prior work on other soil types has shown shear strain to be a more fundamental parameter controlling pore pressure generation and volume change (e.g., Vucetic, 1994). Cyclic, followed by extended consolidation (24 hrs) 9 9-3a 9 Cyclic, followed by extended consolidation 18 9-3a 9 Cyclic, followed by brief consolidation 42…”

Section: Tested Materials and Proceduresmentioning

confidence: 99%

Laboratory Investigation of the Pre- and Post-Cyclic Volume Change Properties of Sherman Island Peat

2013

View full text Add to dashboard Cite

Section: Tested Materials and Proceduresmentioning

confidence: 99%

Laboratory Investigation of the Pre- and Post-Cyclic Volume Change Properties of Sherman Island Peat

2013

View full text Add to dashboard Cite

“…Castro, 1975] and of the applied cyclic strain [e.g. Vucetic, 1994], where the applied cyclic loading presumably induces progressive compaction of a loosely or unevenly packed system [Youd, 1972]. In the current analysis of the pore pressure evolution mechanisms, parameters such as compaction potential or number of loading cycles are not accounted for explicitly.…”

Section: Estimating Liquefaction Potentialmentioning

confidence: 99%

The Mechanical Coupling of Fluid-Filled Granular Material Under Shear

Goren

Aharonov

Sparks

et al. 2011

Pure Appl. Geophys.

View full text Add to dashboard Cite

Abstract. The coupled mechanics of fluid-filled granular media controls the physics of many Earth systems such as saturated soils, fault gouge, and landslide shear zones. It is well established that when the pore fluid pressure rises, the shear resistance of fluid-filled granular systems decreases, and as a result catastrophic events such as soil liquefaction, earthquakes, and accelerating landslides may be triggered. Alternatively, when the pore pressure drops, the shear resistance of these geosystems increases. Despite the great importance of the coupled mechanics of grains-fluid systems, the basic physics that controls this coupling is far from understood. Fundamental questions that need to be addressed are what are the processes that control pore fluid pressurization and depressurization in response to deformation of the granular skeleton? and how do variations of pore pressure affect the mechanical strength of the grains skeleton? To answer these questions, a formulation for the pore fluid pressure and flow is developed from mass and momentum conservation, and is coupled with a granular dynamics algorithm that solves the grain dynamics, to form a fully coupled model. The pore fluid formulation reveals that the evolution of pore pressure obeys a viscoelastic rheology in response to pore space variations. Elastic-like behavior dominates with undrained conditions and leads to a linear relation between pore pressure and overall volumetric strain. Viscous-like behavior dominates under well drained conditions and leads to a linear relation between pore pressure and volumetric strain rate. Numerical simulations reveal the possibility of liquefaction under drained and initially over-compacted conditions, which were often believed to be resistant to liquefaction. Under such conditions liquefaction occurs during short compactive 1 phases that punctuate the overall dilative trend. In addition, the more established generation of elevated pore pressure under undrained compactive conditions is observed. Simulations also show that during liquefaction events stress chains are detached, the external load becomes completely supported by the pressurized pore fluid, and shear resistance vanishes.

show abstract

“…Consequently, at very small γ c there are no noticeable cyclic degradation and permanent cyclic pore water pressure changes. The amplitude γ c below which there is practically no cyclic degradation and above which a noticeable degradation occurs is known as the threshold shear strain for cyclic degradation, γ td (Tabata and Vucetic 2010;Vucetic 1994b). The amplitude γ c below which there is practically no permanent cyclic pore water pressure change with N and above which such a change is clearly noticeable is known as the threshold shear strain for cyclic pore water pressure generation, γ tp (Dobry et al 1982).…”

Section: Introductionmentioning

confidence: 99%

“…As opposed to that, if γ c > γ td the degradation will occur and it should be considered in the analyses. For example, in Vucetic (1994b) it is explained that the selection of the method for seismic site response analysis depends on the relative magnitude of γ td with respect to the magnitudes of γ c generated by the earthquake at the site. If γ c < γ td , the equivalent linear analysis that does not account for cyclic degradation, such as SHAKE (Schnabel et al 1972), is sufficient.…”

Section: Introductionmentioning

confidence: 99%

Threshold Shear Strains for Cyclic Degradation and Cyclic Pore Water Pressure Generation in Two Clays

Mortezaie¹,

Vučetić

2016

J. Geotech. Geoenviron. Eng.

Self Cite

View full text Add to dashboard Cite

Cyclic threshold shear strains are fundamental cyclic soil properties that have not been fully investigated. To learn more about the threshold shear strains for cyclic degradation, γ td , and cyclic pore water pressure generation, γ tp , in fully saturated clays, nine multistage cyclic strain-controlled NGI direct simple shear tests are conducted on laboratory-made kaolinite clay (PI ¼ 28) and kaolinite-bentonite clay (PI ¼ 55). Three levels of vertical effective consolidation stress, σ 0 vc (113 kPa, approximately 216 kPa, and approximately 674 kPa); three OCRs (1, 4 and 7.8); and two cyclic loading frequencies, f (0.01 and 0.1 Hz), were applied. In three tests on the normally consolidated (NC) kaolinite clay, γ td varied between 0.012 and 0.014% and γ tp between 0.014 and 0.034%. In two tests on the overconsolidated (OC) kaolinite clay with OCR ¼ 4, γ td was 0.013% and γ tp 0.016 and 0.017%. In two tests on the NC kaolinite-bentonite clay, γ td was 0.013 and 0.016% and γ tp 0.052 and 0.078%. In the test on OC kaolinite-bentonite clay with OCR ¼ 4, γ td was 0.014% and with OCR ¼ 7.8 it was 0.012%. For the same soil γ tp is typically slightly greater than γ td . Clear trends of γ td and γ tp with σ 0 vc , OCR, and f could not be identified given the relatively small number of tests. The results indicate that if these trends exist they are small. The comparison of the above results with those from the literature shows that γ td for six different soils ranges between 0.006 and 0.05% and γ tp for eight soils between 0.014 and 0.1%, and that there is a modest trend of γ td and moderate trend of γ tp increasing with PI.

show abstract

Cyclic Threshold Shear Strains in Soils

Cited by 414 publications

References 19 publications

Laboratory Investigation of the Pre- and Post-Cyclic Volume Change Properties of Sherman Island Peat

Laboratory Investigation of the Pre- and Post-Cyclic Volume Change Properties of Sherman Island Peat

The Mechanical Coupling of Fluid-Filled Granular Material Under Shear

Threshold Shear Strains for Cyclic Degradation and Cyclic Pore Water Pressure Generation in Two Clays

Contact Info

Product

Resources

About