Embankments and cuttings are used to provide a reasonably uniform vertical alignment to highways. Increasingly, emphasis is being given to the long-term maintenance of these earthworks. Their long-term stability is influenced by a number of factors but of particular importance is the pore water pressure regime. There is a need for accurate pore water pressure data to define in-service conditions and to identify potential and actual failure mechanisms. However, in the main, the pore pressure sensors that have been commonly used are either unreliable or cannot provide a continuous data set. This report reviews the theoretical background and the development of piezometers. It discusses the problems that might be encountered when using such devices, and describes the development, operation and use of a new suite of piezometric equipment designed to continuously monitor the variation in pore water pressure. Data obtained with the new piezometric equipment from a highway embankment are also presented and discussed. (Author/publisher)
Abstract