Intrinsic Compressibility

Oedometer tests were performed on one clay and one marl reconstituted at various initial water contents and consolidated from slurry-like form, in order to investigate the properties of Intrinsic Compressibility and the Intrinsic Compression Line. The properties of Intrinsic Compressibility are found to be very ‘robust’ relative to the initial water content of the slurries. It is also shown that the relationship between Void Index and the logarithm of vertical stress providing the Intrinsic Compression Line can be derived analytically. Finally the time-settlement curves were studied and oedometer tests with reduced time intervals between changes in load were performed in order to study the differences in the values of the properties of Intrinsic Compressibility obtained from the two kinds of tests.

Characterized by high initial void ratio, organic content and water holding capacity, fibrous peat exhibits high compressibility and low shear strength. Consequently, formation of deep fibrous peat layer often poses difficulties in construction. In practice, compressibility of deep fibrous peat layer can be reduced by deep soil stabilization technique. The technique is developed in such a way that dry binders are mixed with in situ peat soil to form columnar reinforcement in the deep peat ground prior to preloading. Preloading simulations of both untreated and stabilized peats were carried out in laboratory by loading of both soils using standard oedometer consolidation apparatus. Ordinary Portland cement, ground granulated blast furnace slag and siliceous sand were used to stabilize the soil. Analysis on the time-compression curves from the tests revealed that coefficients of vertical consolidation (cv of both soils were best predicted using square root of t52.6 method when compared to those evaluated using conventional curve fitting methods. Main reason for this is the experimental time-compression curves for the method best fit its theoretical curve. In addition, the method predicts cv of soil at 52.6% average degree of consolidation, which is less likely to be affected by secondary compression that usually occurs concurrently at the later stage of soil primary consolidation. © 2008 ejge.

ejge.com/2008/Ppr0862/Ppr0862.pdf

Characterized by high initial void ratio, organic content and water holding capacity, fibrous peat exhibits high compressibility and low shear strength. Consequently, formation of deep fibrous peat layer often poses difficulties in construction. In practice, compressibility of deep fibrous peat layer can be reduced by deep soil stabilization technique. The technique is developed in such a way that dry binders are mixed with in situ peat soil to form columnar reinforcement in the deep peat ground prior to preloading. Preloading simulations of both untreated and stabilized peats were carried out in laboratory by loading of both soils using standard oedometer consolidation apparatus. Ordinary Portland cement, ground granulated blast furnace slag and siliceous sand were used to stabilize the soil. Analysis on the timecompression curves from the tests revealed that coefficients of vertical consolidation (c v) of both soils were best predicted using square root of t 52.6 method when compared to those evaluated using conventional curve fitting methods. Main reason for this is the experimental time-compression curves for the method best fit its theoretical curve. In addition, the method predicts c v of soil at 52.6% average degree of consolidation, which is less likely to be affected by secondary compression that usually occurs concurrently at the later stage of soil primary consolidation.

FOR CITATIONS:
SALEM, H.S., 1993. A Preliminary Study of the Physical Properties of the Terra Nova and Hibernia Oil Fields in the Jeanne d'Arc Basin, Offshore Newfoundland, Canada. Geological Survey of Canada, Dossier Public, Halifax, Nova Scotia, OFR-2686, 76 pp. (Technical Report). http://geogratis.cgdi.gc.ca/eodata/download/part6/ess_pubs/184/184196/of_2686.pdf

ABSTRACT:
In this study, huge amounts of petroleum industrial data, with respect to the Hibernia and Terra Nova oil and gas fields, offshore the Eastern Coast of Newfoundland, Canada, were analyzed and interpreted.  Log data, geophysical data, drilling data, geological and engineering data, and oceanographic data were used in this study to have in hand a preliminary evaluation, assessment and characterization of the intended offshore reservoirs, as part of the Jeanne d’Darc Basin’s Hydrocarbon Charge Modeling Project (JDB-HCMP). This project (JDB-HCMP) is a mega project funded by industrial, governmental and academic institutions in Canada and the USA. As a result, a great deal of petrophysical parameters and properties were obtained, including electric, elastic, hydraulic (with respect to geo-fluids, i.e., oil, gas and saline water), lithological, stratigraphic, etc. Wide variations for these parameters were obtained, resulting mainly from the heterogeneity of the lithological components (shales, sandstones, silts, limestones, marls, and conglomerates) and the fluid saturations (oil, gas, saline water) of the reservoirs investigated.