poreznyomásnövekedés

Poreznyomásnövekedés, often translated as pore pressure increase, refers to the phenomenon where the fluid pressure within the pore spaces of a geological formation rises above the initial hydrostatic pressure. This increase can occur due to various geological and anthropogenic processes.

Hydrostatic pressure is the pressure exerted by a column of water in a saturated porous medium. Pore pressure increase signifies a deviation from this equilibrium. Common natural causes include the compaction of sediments, which squeezes pore water, and the dissolution or precipitation of minerals, which can alter pore volume and fluid content. Tectonic stresses can also play a role by reducing pore volume.

Anthropogenic activities are increasingly recognized as significant contributors to pore pressure increase. Fluid injection, such as during wastewater disposal, hydraulic fracturing, or geothermal energy extraction, can directly add fluid to subsurface formations, thereby raising pore pressure. Additionally, reservoir impoundment, like the creation of large dams, can lead to increased pore pressure in surrounding rocks due to the weight of the impounded water and its infiltration into the subsurface.

Elevated pore pressure can have significant geomechanical implications. It can reduce the effective stress acting between soil or rock grains, which is the stress that resists deformation and failure. Consequently, increased pore pressure can lead to a decrease in shear strength, potentially triggering landslides, subsidence, or even seismic events known as induced seismicity. Understanding and monitoring pore pressure is therefore crucial for geological hazard assessment and the safe management of subsurface resources.