Soil quality. Determination of pore water pressure. Tensiometer method

1996 ◽  
Keyword(s):  
Soil Quality ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure

scholarly journals METHOD OF DETERMINATION OF INITIAL PORE WATER PRESSURE OF SATURATED CLAYED GROUND UNDER EMBANKMENT

2009 ◽  
Vol 12 (8) ◽  
pp. 90-96
Author(s):  
Son Truong Bui
Keyword(s):  
Pore Water ◽  
Water Saturation ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Initial Time ◽  
Excess Pore Water Pressure ◽  
Method Of Determination ◽  
Triaxial Cell ◽  
Excess Pore

Base on proposed formulation and testing results, method of determination of initial excess pore water pressure, which is used in filtration consolidation and other geotechnical problems in case of plane and spatial problems. Unlike supposition in initial time t = 0, σ = uwo, i.e. accepting a value of coefficient of initial pore water pressure β=1, by the laboratory testing results in triaxial cell, value of coefficient of initial pore water pressure of weak saturated clayey soils in HoChi Minh City and Mekong delta is lower 1. Output computation and research results show, that initial excess pore water pressure depends on water saturation, value of compression stress and groundwater level. Using the suggested formula allows determining coefficient of initial excess pore water pressure and applies to estimate initial settlement, distribution initial pore water pressure in consolidation and long term settlement.

scholarly journals A Simulation Study on the Spatial-Temporal Characteristics of Pore Water Pressure and Roof Water Inrush in an Aquiclude

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Tao Yang ◽  
Ji Li ◽  
Longwen Wan ◽  
Sheng Wang
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Inrush ◽  
Pressure Change ◽  
Coupling Model ◽  
Early Warning Systems ◽  
Temporal Characteristics ◽  
Working Face

As the working face advances, the overlying aquiclude is subjected to periodic dynamic loads, causing pore water pressure distortion, which provides important forewarning for a water inrush disaster in shallow coal seams. In order to analyze the pore water pressure in an aquiclude and determine the spatial-temporal characteristics of the water inrush, the aquiclude is simplified into a saturated, porous, liquid-solid medium and a viscoelastic dynamic model is created to obtain the analytical solution of the pressure distribution. FLAC3D is used to develop a fluid-solid coupling model and to analyze the characteristics of the pressure change and overburden under different mining intensities. This study on pore water pressure in an aquiclude and the determination of the spatial-temporal characteristics of the water inrush provides a foundation for developing early-warning systems for roof water inrush.

Determination of the Cyclic Properties of Silty Sands

2018 ◽  
pp. 416-445
Author(s):  
Eyyüb Karakan ◽  
Selim Altun
Keyword(s):  
Cyclic Loading ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Triaxial Tests ◽  
Loading Conditions ◽  
Systematic Testing ◽  
Geotechnical Problems ◽  
Insight Into

Liquefaction may be triggered by cyclic loading on saturated silty sands, which is responsible of severe geotechnical problems. Development of excess pore water pressure in soil results in a liquid-like behavior and may be the reason of unavoidable superstructural damage. In this study, in order to investigate the behavior of saturated silty sands exposed to cyclic loading under undrained conditions, a systematic testing program of stress-controlled cyclic triaxial tests was performed on specimens of different silt contents, under different loading conditions and environment. The effect of parameters such as silt content on the liquefaction behavior of specimens was studied. Pore water pressure and shear strain curves were obtained for the silty sands. Furthermore, the boundaries existing in the literature on sands are compared with the results current research, on silty sands. Conclusively, the outcomes of this study were useful to develop insight into the behavior of clean and silty sands under seismic loading conditions.

scholarly journals Generalized effective stress concept for saturated active clays

2020 ◽  
Author(s):  
Angelica Tuttolomondo ◽  
Alessio Ferrari ◽  
Lyesse Laloui
Keyword(s):  
Water Chemistry ◽  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Theoretical Explanation ◽  
Theoretical Development ◽  
Pore Water Chemistry ◽  
Chemical Variable

Experimental evidence shows that changes in pore water chemistry can significantly affect the mechanical behavior of saturated active clays. Despite this evidence, how the chemical composition of the pore water can be considered in effective stress definition is questionable. This paper develops the concept of generalized effective stress for active clays. To this end, physicochemical studies on water–clay mineral interactions are used to clearly define the different types of ions and water present in an active clay. In particular, the presence of both movable and non-movable ions within the liquid water is highlighted. Taking this into account, thermodynamic and geochemistry principles are applied to the representative elementary volume scale for determining the pore water pressure and redefine the effective stress accordingly. The theoretical development results in the dependence of the effective stress on the pore water chemistry through the effective solute suction variable. Equations for the determination of this chemical variable are developed. The implications of the use of the proposed effective stress concept are investigated using experimental results taken from the literature. The results show advantages both in the interpretation of shear strength and volumetric data, and all support the theoretical explanation underlying the proposed concept.

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.

The temperature and pore water pressure in soil subjected to dynamic load

2018 ◽  
Vol 35 (2) ◽  
pp. 111
Author(s):  
Kun ZHANG ◽  
Ze ZHANG ◽  
Xiangyang SHI ◽  
Sihai LI ◽  
Donghui XIAO
Keyword(s):  
Pore Water ◽  
Dynamic Load ◽  
Pore Water Pressure ◽  
Water Pressure
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