Prebored Pressuremeter Testing in-situ soil/Menard pressuremeter

 Standard:  ISO 22476-4, ASTM D-4719-00

The pressuremeter test is an in-situ testing method used to achieve a quick measure of the in-situ stress-strain relationship of the soil. In principle, the pressuremeter test is performed by applying pressure to the sidewalls of a borehole and observing the corresponding deformation.
The pressuremeter consists of two parts, the read-out unit which rests on the ground surface, and the probe that is inserted into the borehole (ground). The original Ménard-type pressuremeter was designed to be lowered into a performed hole and to apply uniform pressure to the borehole walls by means of infl atable fl exible membrane.
As the pressure increases, the borehole walls deform. The pressure is held constant for a given period and the increase in volume required for maintaining the constant pressure is recorded. A load-deformation diagram and soil characteristics can be deduced by measurement of the applied pressure and change in the volume of the expanding membrane.
From the test readings (volume variation based on controlled pressure), a stress-strain curve can be obtained,
in the case of plane deformation, which yields :
• the Ménard Pressuremeter modulus
• the creep pressure
• the Menard limit pressure

Main Components

The Control Unit 

Equipped with devices to precisely regulate the pressure applied to the probe and to read its volume changes with pressure increments and time. A nitrogen cylinder provides the pressure source. The box stands on a tripod.

The plastic tubing 

This coaxial or twin tubing, fl exible, high resistance with small dilatation, connects the probe to the monitoring box.

The 3-cell probe
It includes a central measuring cell, fi lled with water. Its volume changes are read on the Control Unit volumeter. The probe is totally protected by a rubber cover (different types regarding soils stiffness) which is inflated by the gas to form the 2 guard
cells. Pressures applied to the 3 cells are balanced through the differential pressure regulator to ensure a true cylindrical deformation along the measuring cell.

Main Technical Parameter