Pore water pressure

About: Pore water pressure is a research topic. Over the lifetime, 11455 publications have been published within this topic receiving 247670 citations. The topic is also known as: pwp.

Chemical diagenesis of some modern carbonate sediments

Abstract: Mineralogy and pore water chemistry of fine-grained carbonate sediments from Bermuda and south Florida indicate that aragonite and high-Mg calcite do not tend to recrystallize to low-Mg calcite and dolomite in sediments that always have been in contact with sea water; in these sediments ratios of Mg (super ++) and Sr (super ++) to Cl (super -) in pore water are similar to ratios in the overlying sea water. Pore waters from brackish mangrove swamp sediments contain more Mg (super ++) than would be expected from Mg (super ++) /Cl (super -) ratios of the overlying brackish water and of sea water; presumably transformation from high-Mg calcite to low-Mg calcite takes place by interaction with fresh water.

Soil Deformation and Excess Pore Pressure Field around a Closed-Ended Pile

Abstract: Numerous field and laboratory research projects have examined loading conditions, total soil stresses, and excess pore pressures during and following pile installation. Recently, a large number of seismic retrofitting projects for bridges in California have revealed the need for well-documented field tests evaluating the effect of pile installation on the static and dynamic properties of soft clays. This paper documents the geotechnical field investigation and field monitoring program, which included measurements of excess pore pressure and horizontal deformations at three radial distances from a full-scale close-ended pile driven into a deep deposit of Young Bay Mud. Significant excess pore pressures developed as a result of pile driving and they are a function of distance to the pile wall. Lateral deformations decrease with increasing distance from the pile and can be approximately described by the cylindrical cavity expansion method. iclinometer measurements show lateral deformation towards the pile wall as the excess pore pressure dissipates. These measurements are essential in the calibration and validation of analytical techniques to predict changes in properties of the foundation soil.

On the effective stress in unsaturated porous continua with double porosity

Abstract: Using mixture theory we formulate the balance laws for unsaturated porous media composed of a double-porosity solid matrix infiltrated by liquid and gas. In this context, the term ‘double porosity’ pertains to the microstructural characteristic that allows the pore spaces in a continuum to be classified into two pore subspaces. We use the first law of thermodynamics to identify energy-conjugate variables and derive an expression for the ‘effective’, or constitutive, stress that is energy-conjugate to the rate of deformation of the solid matrix. The effective stress has the form σ ¯ = σ + B p ¯ 1 , where σ is the total Cauchy stress tensor, B is the Biot coefficient, and p ¯ is the mean fluid pressure weighted according to the local degrees of saturation and pore fractions. We identify other emerging energy-conjugate pairs relevant for constitutive modeling of double-porosity unsaturated continua, including the local suction versus degree of saturation pair and the pore volume fraction versus weighted pore pressure difference pair. Finally, we use the second law of thermodynamics to determine conditions for maximum plastic dissipation in the regime of inelastic deformation for the unsaturated two-porosity mixture.