Water pressure inside rocks, or pore pressure, is high in some areas and low in others, he said, keeping the fault weak.

The electrokinetic effect is associated with the motion of groundwater during a change in pore pressure.

Negative pore pressures in clayey soil can be much more powerful than those in sand.

The pore pressures of the layers over the reservoir are also very dangerous, as they vary greatly from one to the next.

He was among the first to recognize that change in pore pressure developed during undrained shearing.

In this case, sudden earthquake forces immediately increases the pore pressure of shallow groundwater.

However, the pore pressure is usually much greater than a column of fresh water, and can be as much as 19 lb/U.

For a uniform layer with no pore pressure, the total vertical stress at a depth may be calculated by:

This densification drives up the pore pressure in the material.

Depending on the magnitude of the pore pressure, it can be described as being normal, abnormal or subnormal.