Centrifuge modelling of active earth pressures

2010 ◽  
pp. 531-536
Keyword(s):  
Centrifuge Modelling ◽  
Earth Pressures

Earth pressures on unyielding retaining walls of narrow backfill width

2001 ◽  
Vol 38 (6) ◽  
pp. 1220-1230 ◽  
Author(s):  
W A Take ◽  
A J Valsangkar
Keyword(s):  
Earth Pressure ◽  
Friction Angle ◽  
Retaining Walls ◽  
Centrifuge Modelling ◽  
Reasonable Estimate ◽  
Interface Friction ◽  
Centrifuge Tests ◽  
Earth Pressures ◽  
Nonlinear Calibration ◽  
Good Agreement

Arching theory predicts a significant reduction in earth pressures behind retaining walls of narrow backfill width. An extensive series of centrifuge tests has been performed to evaluate the use of flexible subminiature pressure cells in the centrifuge environment and their subsequent use to measure lateral earth pressures behind retaining walls of narrow backfill width. Although the flexible earth pressure cells exhibit hysteresis and nonlinear calibration behaviour, the extensive calibration studies indicate that stiff diaphragm type earth pressure cells may be used with replicate models to measure earth pressures. Measurements of lateral pressures acting on the unyielding model retaining walls show good agreement with Janssen's arching theory. Tests on backfills bounded by vertical planes of dissimilar frictional characteristics indicate arching theory with an average interface friction angle provides a reasonable estimate of lateral earth pressures.Key words: fascia retaining walls, silos, earth pressures, pressure cells, centrifuge modelling.

Measurement of earth pressures by means of the flat jack test

1953 ◽  
Author(s):  
P. Habib ◽  
R. Marchand ◽  
Severine Britt
Keyword(s):  
Earth Pressures

scholarly journals Geomechanical Behaviour of Uncemented Expanded Polystyrene (EPS) Beads–Clayey Soil Mixtures as Lightweight Fill

Geotechnics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 38-58
Author(s):  
Pouyan Abbasimaedeh ◽  
Ali Ghanbari ◽  
Brendan C. O’Kelly ◽  
Mohsen Tavanafar ◽  
Kourosh Ghaffari Irdmoosa
Keyword(s):  
Clayey Soil ◽  
Expanded Polystyrene ◽  
Environmental Cost ◽  
Dry Density ◽  
Engineering Practice ◽  
Clayey Sand ◽  
Earth Pressures ◽  
Lightweight Fill ◽  
Soil Foundation ◽  
Geotechnical Testing

Lightweight fill can be advantageous in embankment construction for the purposes of reducing the (i) bearing pressures on the underlying soil foundation, (ii) destabilizing moments for constructed earthen slopes, and (iii) earth pressures acting behind retaining walls. This paper investigates the merits/limitations of particulate expanded polystyrene (EPS) beads mixed with clayey sand (CS) soil as lightweight fill, considering both geotechnical and environmental perspectives. The bench-scale geotechnical testing programme included standard Proctor (SP) compaction, California bearing ratio (CBR), direct shear (sheardox), oedometer and permeability testing performed on two different gradation CS soils amended with 0.5, 1.5 and 3.0 wt.% EPS, investigating two nominal bead sizes equivalent to poorly-graded medium and coarse sands. Compared to the unamended soils, the compacted dry density substantially decreased with increasing EPS beads content, from 2.09 t/m3 (0 wt.% EPS) to as low as 0.33 t/m3 for 3 wt.% (73 v.%) of larger-sized EPS beads. However, from analyses of the test results for the investigated 50 to 400 kPa applied stress range, even 0.5 wt.% (21 v.%) EPS beads caused a substantial mechanical failure, with a drastic decay of the CBR and compressibility parameters for the studied CS soils. Given the more detrimental environmental cost of leaving myriads of separate EPS beads mixed forever among the soil, it is concluded that the approach of adding particulate EPS beads to soils for producing uncemented lightened fill should not be employed in geotechnical engineering practice.

The Principle of Effective Stress Theory Research Based on Channel Rate

2013 ◽  
Vol 275-277 ◽  
pp. 336-342
Author(s):  
Xiao Feng Wu ◽  
Guang Fan Li ◽  
Wan Cheng He
Keyword(s):  
Effective Stress ◽  
Permeability Coefficient ◽  
Cohesive Soil ◽  
Stress Equation ◽  
Jump Problem ◽  
Stress Theory ◽  
Conventional Calculation ◽  
Earth Pressures ◽  
Stress Surface ◽  
Theory Research

Based on the debate of effective stress principle applicability on cohesive soil in recent years and the predecessor's research achievements, this paper puts forward the idea that the effective stress surface including hydrated film surrounding soil particles. And we obtained the extended soil effective stress equation by establishment of the model of channel rate.Combined with the physical significance of permeability coefficient and substantial experimental data, it can establish the fitting equation between permeability coefficient and new proposed physical parameter channel rate. A new calculation method to unify the separate calculation and combined calculation of water and earth pressures is proposed to carry out the transition between results of the two conventional calculation methods and provide a new idea for solving the jump problem between the two results.

Earth pressures exerted on an induced trench cast-in-place double-cell rectangular box culvert

2012 ◽  
Vol 49 (11) ◽  
pp. 1267-1284 ◽  
Author(s):  
Olajide Samuel Oshati ◽  
Arun J. Valsangkar ◽  
Allison B. Schriver
Keyword(s):  
Earth Pressure ◽  
Test Results ◽  
Overburden Pressure ◽  
Centrifuge Testing ◽  
Geotechnical Centrifuge ◽  
Drag Forces ◽  
Field Instrumentation ◽  
Earth Pressures ◽  
Box Culvert ◽  
Base Contact

Earth pressure data from the field instrumentation of a cast-in-place reinforced rectangular box culvert are presented in this paper. The instrumented culvert is a 2.60 m by 3.60 m double-cell reinforced cast-in-place rectangular box buried under 25.10 m of fill constructed using the induced trench installation (ITI) method. The average earth pressure measured across the roof was 0.42 times the overburden pressure, and an average of 0.52 times the overburden pressure was measured at mid-height of the culvert on the sidewalls. Base contact pressure under the rectangular box culvert was also measured, providing field-based data demonstrating increased base pressure resulting from downward drag forces developed along the sidewalls of the box culvert. An average increase of 25% from the measured vertical earth pressures on the roof plus the culvert dead load (DL) pressure was calculated at the culvert base. A model culvert was also tested in a geotechnical centrifuge to obtain data on earth pressures at the top, sides, and base of the culvert. The data from the centrifuge testing were compared with the prototype structure, and the centrifuge test results agreed closely with the measured field prototype pressures, in spite of the fact that full similitude was not attempted in centrifuge testing.

Centrifuge modelling of wet deep mixing processes in soft clays

Géotechnique ◽  
2006 ◽  
Vol 56 (10) ◽  
pp. 677-691 ◽  
Author(s):  
F. H. Lee ◽  
C. H. Lee ◽  
G. R. Dasari
Keyword(s):  
Centrifuge Modelling ◽  
Mixing Processes ◽  
Soft Clays ◽  
Deep Mixing
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