APPARATUS FOR MEASURING IN SITU THE PERMEABILITY OF A CIVIL ENGINEERING WORKING STRATUM

摘要

The permeability of a flat surface is measured, by pressing down on the surface a central chamber surrounded by an annular chamber. The chambers are open at their bottom, and in the annular chamber is disposed a flexible annular bladder. Air is pumped into the bladder to seal about the central chamber, and then liquid under a predetermined pressure is introduced into the central chamber. The pressure of the liquid is no greater than the pressure of the air in the annular chamber and so the liquid does not leak out laterally. The flow rate of liquid into the central chamber thus indicates the permeability of the subjacent material.