PURPOSE OF PIEZOMETER MONITORING
- Analyzing and evaluating the consolidation process of the ground.
- Checking the actual status of the construction close to the calculation status when designing or not to decide on emergency measures in the field.
- Knowing the actual status of soft soil under construction to check the value of some parameters used when designing.
METHOD OF PIEZOMETER MONITORING
Piezometer installation is done as follows:
- Drilling 100mm diameter borehole to the requested depth and piezometer tip installed in clayey sand layer.
- Installing piezometer sensor at the bottom of borehole, then filling borehole in turn by 1 – 2 m sand or small grave, 1 – 2 m bentonite pellets and grouting bentonite full the borehole.
Piezometer sensors are installed in borehole. Its sensing mechanism consists of a tensioned steel wire, a diaphragm, and an electromagnetic coil. Pressure causes the diaphragm to deflect, reducing tension in the wire. The vibrations of the wire near the coil generates a frequency signal that is transmitted via a signal cable to the readout device.
APPLIED STANDARD
- TCVN 8869:2011 “Method for measurements of pore pressures in soil”.
- AASHTO T252:96 “Standard Method of Test for Measurements of Pore Pressures in Soils”.
