UBC Theses and Dissertations
In-situ testing techniques applied to embankments over soft organic soils Brown, Stephen Granger
The investigation of a test fill over organic soils has been carried out using three in-situ testing techniques. One-half of the fill area is serviced by wick drains while the other half remains in a natural state. Piezometer cone penetration tests, dilatometer tests and field vane tests were used to monitor the test embankment over a one year period during both the construction and consolidation phases. The ability of these tests to monitor embankments is evaluated. The results show that the piezometer cone penetration test gives the best overall performance. The results also show that the wick drains improved the drainage of the organic soils significantly. In a separate study, piezometer cone penetration tests, dilatometer tests and screw plate tests were performed to determine engineering properties of the organic soil such as undrained shear strength, coefficient of consolidation and drained constrained modulus. The strengths and weaknesses of each test are discussed with particular reference to the testing of organic soils. Finally, predictions of settlement are made from the in-situ drained moduli and are compared with the observed settlements. Settlements predicted using Sanglerat's (1972) correlation for drained modulus for the cone penetration test were found to compare well with the observed values.
Item Citations and Data