Geotechnics of organic soils and peat

Peat and organic soils commonly occur as extremely soft, wet, unconsolidated surficial deposits that are an integral part of wetland systems. These types of soils can give rise to geotechnical problems in the area of sampling, settlement, stability, in situ testing, stabilisation and construction. There is therefore a tendency to either avoid building on these soils, or, when this is not possible, to simply remove or replace soils, which in some instances can lead to possibly uneconomical design and construction alternatives. However, in many countries of the world, these soils cover a substantial land area and pressure on land use is resulting in ever more frequent utilisation of such marginal grounds. For the successful design, construction and performance of structures on such marginal soils, it is crucial to predict geotechnical behaviour in terms of settlement, shear strength and stability, with respect to time. This means expanding our knowledge base and calls for a reliable characterisation of their geotechnical properties and mechanical behaviour and subsequently, the devising of suitable design parameters and construction techniques for dealing with these materials. A sound scientific understanding of the nature and functions of peat and organic soils is critical to their correct and safe use, and this book contributes by offering students, researchers, engineers and academics involved with these types of soils a comprehensive overview. This book will be useful not only to those in the field of geotechnical engineering, but also to soil scientists and agriculturalists, who are involved in the development of peatlands

Soil-Framed Structure Interaction Analysis - A New Interface Element

AbstractInterfacial behavior between soil and shallow foundation has been found so influential to combined soil-footing performance and redistribution of forces in the superstructure. This study introduces a new thin-layer interface element formulated within the context of finite element method to idealize interfacial behavior of soil-framed structure interaction with new combination of degrees of freedom at top and bottom sides of the interface element, compatible with both isoparametric beam and quadrilateral element. This research also tends to conduct a parametric study on respective parameters of the new joint element. Presence of interface element showed considerable changes in the performance of the framed structure under quasi-static loading

Improvement of settlement problems of fibrous peat

The distribution of peat deposits can be found in many countries and peat-land constituents from 5-8% of earth land surface, where approximately 60% of the wetlands are peat. An increasing growth of the population leads to the necessity of peat-land utilization for development purposes. This article describes a laboratory study on the effect of different binders on the settlement of fibrous peat. The effect of sodium silicate, ordinary Portland cement, and kaolinite on the settlement of peat is investigated through the Rowe Cell consolidation test. At the end of this study, it is shown by increasing sodium silicate (within 2.5%), cement, and kaolinite on treated peat, they are able to improve settlement of fibrous peat much more than conventional binders such as pure cement. © 2014 ASCE