scholarly journals Cyclic Shear Behavior of Unsaturated Soil with Varying Pore Water and Pore Air Condition

2019 ◽  
Vol 19 (5) ◽  
pp. 5_170-5_183
Author(s):  
Toshiyasu UNNO ◽  
Yusuke MIDORIKAWA
Keyword(s):  
Pore Water ◽  
Unsaturated Soil ◽  
Shear Behavior ◽  
Cyclic Shear

TIME TO THE END OF PRIMARY CONSOLIDATION (EOP) OF SOFT CLAYEY SOILS: CONCERNING THE EFFECT OF ATTERBERG’S LIMIT AND CYCLIC LOADING HISTORY

2019 ◽  
Vol 128 (2B) ◽  
pp. 29-41
Author(s):  
Trần Thanh Nhàn
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Clayey Soils ◽  
Loading History ◽  
Cyclic Shear ◽  
Wide Range ◽  
Primary Consolidation ◽  
Time Required

In order to observe the end of primary consolidation (EOP) of cohesive soils with and without subjecting to cyclic loading, reconstituted specimens of clayey soils at various Atterberg’s limits were used for oedometer test at different loading increments and undrained cyclic shear test followed by drainage with various cyclic shear directions and a wide range of shear strain amplitudes. The pore water pressure and settlement of the soils were measured with time and the time to EOP was then determined by different methods. It is shown from observed results that the time to EOP determined by 3-t method agrees well with the time required for full dissipation of the pore water pressure and being considerably larger than those determined by Log Time method. These observations were then further evaluated in connection with effects of the Atterberg’s limit and the cyclic loading history.

Stress–strain pattern–based criterion to assess cyclic shear resistance of soil from laboratory element tests

2016 ◽  
Vol 53 (9) ◽  
pp. 1460-1473 ◽  
Author(s):  
Dharma Wijewickreme ◽  
Achala Soysa
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shear Stiffness ◽  
Large Strains ◽  
Fundamental Parameter ◽  
Stress Strain ◽  
Cyclic Shear ◽  
Excess Pore Water Pressure ◽  
Excess Pore

The cyclic shear response of soils is commonly examined using undrained (or constant-volume) laboratory element tests conducted using triaxial and direct simple shear (DSS) devices. The cyclic resistance ratio (CRR) from these tests is expressed in terms of the number of cycles of loading to reach unacceptable performance that is defined in terms of the attainment of a certain excess pore-water pressure and (or) strain level. While strain accumulation is generally commensurate with excess pore-water pressure, the definition of unacceptable performance in laboratory tests based purely on cyclic strain criteria is not robust. The shear stiffness is a more fundamental parameter in describing engineering performance than the excess pore-water pressure alone or shear strain alone; so far, no criterion has considered shear stiffness to determine CRR. Data from cyclic DSS tests indicate consistent differences inherent in the patterns between the stress–strain loops at initial and later stages of cyclic loading; instead of relatively “smooth” stress–strain loops in the initial parts of loading, nonsmooth changes in incremental stiffness showing “kinks” are notable in the stress–strain loops at large strains. The point of pattern change in a stress–strain loop provides a meaningful basis to determine the CRR (based on unacceptable performance) in cyclic shear tests.

Experimental study and evaluation of shear behavior of unsaturated soil-steel interfaces

2014 ◽  
pp. 1341-1347
Author(s):  
Yue Liang ◽  
Chang-Xian Wang ◽  
Guang-Chun He ◽  
Shi-Liang Zhou
Keyword(s):  
Experimental Study ◽  
Unsaturated Soil ◽  
Shear Behavior

Cyclic shear behavior and seismic response of partially saturated slopes

2012 ◽  
Vol 42 ◽  
pp. 71-79 ◽  
Author(s):  
Rolando P. Orense ◽  
Norimasa Yoshimoto ◽  
Masayuki Hyodo
Keyword(s):  
Seismic Response ◽  
Shear Behavior ◽  
Cyclic Shear ◽  
Partially Saturated

Evaluation of a simplified soil constitutive model considering implied strength and pore-water pressure generation for one-dimensional (1D) seismic site response

2020 ◽  
Vol 57 (7) ◽  
pp. 974-991 ◽  
Author(s):  
Xuan Mei ◽  
Scott M. Olson ◽  
Youssef M.A. Hashash
Keyword(s):  
Constitutive Model ◽  
Shear Strain ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Site Response ◽  
Water Pressure ◽  
Generation Model ◽  
Cyclic Shear ◽  
Centrifuge Tests ◽  
Spectral Accelerations

Pore-water pressure (PWP) generation can lead to soil softening and liquefaction of sandy soils during earthquakes, with potential influence on site response and seismic design. The authors evaluated the generalized quadratic/hyperbolic (GQ/H) constitutive model, which captures small-strain stiffness, large-strain shear strength, and is coupled with a widely used cyclic strain–based PWP generation model (termed GQ/H+u). A suite of cyclic direct simple shear tests with a range of relative densities (∼30%–80%) and effective vertical stresses (∼25–200 kPa) and dynamic centrifuge tests with liquefiable sands were used to evaluate the ability of the GQ/H+u model to simulate cyclic soil behavior. Results indicate that GQ/H+u provides reasonable estimates of PWP increase during cyclic shear, with differences between measured and computed excess PWP ratios (ru) for both element and centrifuge tests generally smaller than 0.1. Computed spectral accelerations are comparable to centrifuge test measurements, with almost no bias at medium to long periods (T > 0.4 s) when the computed maximum shear strain (γmax) was smaller than the limit shear strain (γlimit). When computed ru > 0.8 and computed γmax > γlimit, spectral accelerations may be underestimated at both short and long periods as dilative behavior is not captured by GQ/H+u.

scholarly journals PORE AIR PRESSURE EFFECT ON CYCLIC SHEAR BEHAVIOR OF UNSATURATED SANDY SOIL

2013 ◽  
Vol 69 (3) ◽  
pp. 386-403 ◽  
Author(s):  
Toshiyasu UNNO ◽  
Ryosuke UZUOKA ◽  
Noriaki SENTO ◽  
Motoki KAZAMA
Keyword(s):  
Sandy Soil ◽  
Pressure Effect ◽  
Shear Behavior ◽  
Air Pressure ◽  
Cyclic Shear

Cyclic and post-cyclic shear behavior of low-plasticity silt with varying clay content

2015 ◽  
Vol 75 ◽  
pp. 112-120 ◽  
Author(s):  
Shuying Wang ◽  
Ronaldo Luna ◽  
Honghua Zhao
Keyword(s):  
Clay Content ◽  
Shear Behavior ◽  
Cyclic Shear
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