scholarly journals Intensive Measurements of Soil Pore Water Pressure for Analyzing Heterogeneous Hydrological Processes on a Hillslope

2010 ◽  
Vol 3 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Naoya MASAOKA ◽  
Yosuke YAMAKAWA ◽  
Ken'ichirou KOSUGI ◽  
Takahisa MIZUYAMA ◽  
Daizo TSUTSUMI
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Hydrological Processes ◽  
Soil Pore Water

Laboratory calibration of pressure transducer-tensiometer system for hydraulic studies

1994 ◽  
Vol 74 (3) ◽  
pp. 315-319 ◽  
Author(s):  
R. H. Azooz ◽  
M. A. Arshad
Keyword(s):  
Pore Water ◽  
Pressure Transducer ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Hydraulic Gradient ◽  
Gradient Distribution ◽  
Pressure Transducers ◽  
Soil Pore Water ◽  
Laboratory Calibration ◽  
Influence Of Temperature On

Pressure transducer-tensiometer (PTT) systems can be used to continuously monitor soil pore water pressure and the hydraulic gradient distribution in a field, and under laboratory conditions over relatively short time intervals. A reliable laboratory calibration of a PTT system can determine the effects of temperature fluctuations on output readings in the field. Laboratory calibrations of 20 PTTs were conducted under constant pressures of 0, − 25, − 50 and − 75 kPa and constant temperatures of 5, 15, 25 and 48 °C. Twenty Bourdon gauge tensiometers (BGTs) and pressure transducers (PTs) were also calibrated to check changes in the sensitivity and effectiveness of the PTT system, when the Bourdon gauge of the tensiometer is replaced by a PT. Readings of all the three systems revealed that pressure values gradually declined with an increase in temperature. With a temperature change from 5 to 48 °C, the pressure values at constant pressures of 0, − 25, − 50 and − 75 kPa decreased by 0, 3.7, 4.1 and 4.5 kPa for the BGT; 2.05, 2.16, 2.23 and 2.44 kPa for PT and 2.53, 2.87, 2.88 and 3.17 kPa for PTT. As the influence of temperature on the calibration curve of the PTT and PT systems was different, it is recommended that the complete PTT system should be calibrated in the laboratory to adjust the output readings to the anticipated temperature in the field. Key words: Tensiometer, tensiometer-pressure transducer, soil pore water pressure, hydraulic gradient

scholarly journals Artificial Neural Network Modeling for Spatial and Temporal Variations of Pore-Water Pressure Responses to Rainfall

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
M. R. Mustafa ◽  
R. B. Rezaur ◽  
H. Rahardjo ◽  
M. H. Isa ◽  
A. Arif
Keyword(s):  
Neural Network ◽  
Time Series ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Temporal Variations ◽  
Spatial And Temporal Variations ◽  
Ann Model ◽  
Soil Pore Water ◽  
Pore Water Pressures

Knowledge of spatial and temporal variations of soil pore-water pressure in a slope is vital in hydrogeological and hillslope related processes (i.e., slope failure, slope stability analysis, etc.). Measurements of soil pore-water pressure data are challenging, expensive, time consuming, and difficult task. This paper evaluates the applicability of artificial neural network (ANN) technique for modeling soil pore-water pressure variations at multiple soil depths from the knowledge of rainfall patterns. A multilayer perceptron neural network model was constructed using Levenberg-Marquardt training algorithm for prediction of soil pore-water pressure variations. Time series records of rainfall and pore-water pressures at soil depth of 0.5 m were used to develop the ANN model. To investigate applicability of the model for prediction of spatial and temporal variations of pore-water pressure, the model was tested for the time series data of pore-water pressure at multiple soil depths (i.e., 0.5 m, 1.1 m, 1.7 m, 2.3 m, and 2.9 m). The performance of the ANN model was evaluated by root mean square error, mean absolute error, coefficient of correlation, and coefficient of efficiency. The results revealed that the ANN performed satisfactorily implying that the model can be used to examine the spatial and temporal behavior of time series of pore-water pressures with respect to multiple soil depths from knowledge of rainfall patterns and pore-water pressure with some antecedent conditions.

Evaluation of MLP-ANN Training Algorithms for Modeling Soil Pore-Water Pressure Responses to Rainfall

2013 ◽  
Vol 18 (1) ◽  
pp. 50-57 ◽  
Author(s):  
M. R. Mustafa ◽  
R. B. Rezaur ◽  
S. Saiedi ◽  
H. Rahardjo ◽  
M. H. Isa
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Training Algorithms ◽  
Soil Pore Water

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.

Conjectures, Hypotheses, and Theories of Drumlin Formation (In memory of Stanislaw Baranowski)

1981 ◽  
Vol 27 (97) ◽  
pp. 503-505 ◽  
Author(s):  
Ian J. Smalley
Keyword(s):  
Shear Strength ◽  
Pore Water ◽  
Stress Level ◽  
Critical Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Glacial Till ◽  
Forming Process ◽  
Stress Levels

AbstractRecent investigations have shown that various factors may affect the shear strength of glacial till and that these factors may be involved in the drumlin-forming process. The presence of frozen till in the deforming zone, variation in pore-water pressure in the till, and the occurrence of random patches of dense stony-till texture have been considered. The occurrence of dense stony till may relate to the dilatancy hypothesis and can be considered a likely drumlin-forming factor within the region of critical stress levels. The up-glacier stress level now appears to be the more important, and to provide a sharper division between drumlin-forming and non-drumlin-forming conditions.

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