Pore Pressure Generation

Shi, Y. and Ch.-Y. Wang, 1986. Pore pressure generation in sedimentary basins overloading versus aquathermal. Journal of Geophysical Research, Vol. 91, no. B2, pp. 2153-2162... 

The accumulation of hydrogen ions at the anode decreases the pH and moves toward the cathode as an acid front. Similarly, the hydroxyl ions accumulating at the cathode increases the pH and begins to move toward the anode as a base front. However, the acid front moves much faster than the base front because the mobility of hydrogen ions is 1.75 times that of hydroxyl ions. The movement of these fronts should be considered in the overall formulation of the model. Lemaire, Moyne, and Stemmelen (2007) expressed the need to account for the negative pore pressure generated by the electrolysis of water and included the pH effects to account for this. 

Effective stress-strain approaches in which one attempts to determine analytically the pore water pressures generated and their influence on the soil behavior. Laboratory tests on the sediments are utilized at a more fimdamental level to determine pore pressure generation characteristics... 

Cyclic Pore Pressure Generation, Dissipation and Densification in Granular Mixes... 

Ottawa Sand-Silt Mix The data for clean sand and non-plastic silty sand up to 25% silt content (Figures 2a-c) follow the envelope for clean sand reported by Seed at al. (1976). They agree with the results reported by others (Guo and Prakash 1999, 2000). The data for Ottawa sand-silt mixtures at intermediate silt contents of 40 and 60% (Figures 2d-e) fall above the Seed et al. envelope for clean sand and indicate a faster pore pressure generation initially and a slower rate with further cyclic loading. The data for 100% silt (sil-co-sil 40) follows the upper boimd Seed et al. envelope (Figures 2f). 

A comprehensive laboratory experimental study on pore pressure generation, post-liquefaction... 

While this factor is easy to visualise in the case of free-field sites, its estimation is more involved when liquefaction below foundations of existing structures is being considered primarily as it involves the calculation of initial effective stress cr. The range of r varies from 0 to 1 i.e. no excess pore pressures generated to full liquefaction condition. When the value of r reaches... 

Figure 7. Earthquake-induced excess-pore-pressure generation in level sand beds (Coelho et al, 2007). (a) RD = 50% (b) RD = 80%...

Sitharam, T. G., Vinod, J. S. (2008). Numerical simulation of liquefaction and pore pressure generation in granular materials using DEM. IntemationalJoumal of Geotechnical Engineering, 2(2), 103-113.doi 10.3328/UGE.2008.02.02.103-113... 

On the other hand, most fine-grained soils experience initial excess pore on the same order of magnitude as the applied stress even when static permanent loads are applied at the rates normally expected of. Whereas, when the loads are applied at a faster rate such as those expected of for the day-to-day hve loads and for the seismic loads, little or no excess pore pressure generates in most low-permeable finegrained soils. 

Similar to dynamic compaction except vertical or horizontal drains (or together with vacuum) are used to dissipate pore pressures generated in soil during compaction. 

Seed and Harder. SPT-based Analysis of Cyclic Pore Pressure Generation and Undrained Residual Strength, Proc., H.B. Seed Memorial Symp., Vol. 2, BiTech Publishing, Vancouver, B.C., Canada, 351-376, 1990. 

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