Question

why dams are built with broad base

Answer 1

When the water goes deep then pressure increases and the pressure on the surface level is low so the bottom of the dam is strong enough to stand with the pressure.Even when construct we put the basement as strong and construct the walls on the top as thin.That is the logic.

Answer 2

Answer:

as we know that , pressure is the force acting per unit area.dams have large water storage.if the bottom of the dams are not made broad , the large hydraulic pressure may cause dams to sink into the earth's basin.so,an increase in base area,decreases the pressure exerted by large water storage.