The Vibrating Wire Piezometer (VWP) uses a vibrating wire pressure transducer to accurately measure the pore water pressure of the ground by responding to changes in water pressure. This installation is suitable for use in all soil types, with the readings obtained either by a read-out, terminal unit or data logger.
Lankelma can utilise one of two types of VWPs, depending on the nature of the ground. In soft, cohesive soils it is possible to install a push-in VWP via a CPT push. For firmer soils, the VWP is lowered into a 55mm borehole before being fully grouted in place with bentonite-cement.
Applications of the VWP include:
- Determination of slope stability and safe rates of fill or excavation
- Monitoring the effects of dewatering systems used for excavations, and of ground improvement systems (vertical drains and sand drains)
- Examination of the performance of earth fill dams and embankments, and containment systems at landfills and tailings dams
