Embankments on Organic SoilsEdited by
- J. Hartlén, Swedish Geotechnical Institute, Linköping, Sweden
- W. Wolski, Warsaw Agricultural University, Department of Geotechnics, Warsaw, Poland
More and more civil engineering constructions are being built on soft soils. As areas with better foundations are used up the necessity to be able to build structures on soft soils increases.
The most troublesome of soft soils are organic soils due mainly to their high compressibility (much higher than in mineral soils), and also their very low shear strength. The large diversity of organic soils with respect to their origin as well as their properties make classification, testing, and engineering prediction of behaviour, very difficult. For this reason, engineers try, in general, to avoid constructing on deep layers of organic soils. If forced, by necessity, to do so, they manage with light structures e.g. embankments or low buildings.
The authors of this book have been involved in a joint research project on the testing of embankments on organic soils. This was carried out in the North-Western part of Poland by the Swedish Geotechnical Institute and the Department of Geotechnics of Warsaw Agricultural University.The results of their research is presented in this new book and provides a valuable insight into this growing area in the field of engineering geology.
Developments in Geotechnical Engineering
Published: November 1996
- Preface. Notation and symbols. Introduction (J. Hartlén, W. Wolski). I. Testing and Analysis. Organic soils (R. Larsson). Geological origin. Engineering properties. Soil classification.References. Site investigations (U. Bergdahl). General. Mapping, general survey. Soil layer sequence.Groundwater. Strength and deformation characteristics. Monitoring equipment. Test embankments fordesign purposes. References. Laboratory investigations (Z. Lechowicz, A. Szymanski, T. Baranski).General. Routine tests. Determination of stress history. Determination of deformation and consolidationparameters by oedometer tests. Determination of deformation parameters by triaxial test. Determinationof shear strength. Determination of permeability. References. Stability analysis (Z. Lechowicz).General. Shear strength used in stability analysis. Methods of stability analysis. Stability of single-stageembankment. Stability of stage-constructed embankments. Other approaches in stability analysis.References. Analysis of subsoil deformations (A. Szymanski). General. Deformation andconsolidation parameters. Analysis of "final" deformation. Consolidation analysis. Consolidationanalysis of subsoil with vertical drains. Swelling analysis. Development trends in deformation andconsolidation analysis. References. II: Design and Construction Methods. Methods of construction(J. Hartlén). General. Choice of method. Review of basic concepts of embankment construction onorganic soils. Load adjustment (P. Carlsten). Profile lowering. Pressure berms. Lightweight fills.References. Replacement (P. Carlsten). General. Excavation and backfill. Progressive displacement.References. Staged construction (W. Wolski). General. Precompression technique. Vertical drains.Construction monitoring. Construction aspects. Design example for staged embankment with the useof vertical drains. Design example for the staged embankment with surcharging. References. Lime and lime/cement columns (P. Carlsten). Description of the method. Requirements for field andlaboratory investigations. Design considerations. Limitations. Construction aspects. Requirements forfield measurements. Example: Dimensioning of lime columns for reduction of settlements and forstabilisation of a road embankment on soft and organic clay. References. Other methods (P.Carlsten). Reinforcement. Pile foundation. References. Author Index. Subject Index.