Why might the infiltration of water deep into a slide mass increase landslide hazards?
A)Deep infiltration forces vegetation to root more deeply.
B)Water will erode the subsurface materials, reducing strength of the slide mass.
C)Water in the deep subsurface influences soil formation, leading to shallow soil slips.
D)The water increases the pore water pressure, effectively lifting the slide mass from stable ground beneath.

Question

Quizplus · Accepted Answer

When water infiltrates deep into a slide mass, it increases the pore water pressure, which is the pressure exerted by water within the soil pores. This excess pressure reduces the effective stress within the soil, which is the stress that is transferred between soil particles through interlocking and friction. As a result, the slide mass may become buoyant, effectively lifting it from the stable ground beneath and increasing the landslide hazards.

Why Might the Infiltration of Water Deep into a Slide