Centrifuge modelling of ground improvement for double porosity clay (eBook)

Emma Jane Pooley (Autor)

eBook Download: PDF

2015 | 1. Auflage
270 Seiten
vdf Hochschulverlag AG
978-3-7281-3652-7 (ISBN)

Infos

Double porosity soil is characterised by a soil continuum containing two distinct porosities. Typically, this consists of macro-grains (lumps) of soil that have an internal porosity defined as the intragranular porosity. The spaces between lumps are identified as intergranular voids that give rise to the intergranular porosity. Human activities such as land reclamation or mining can give rise to large areas of land with subsoil that exhibits double porosity. The need to build in, or on, these areas is increasing, due to demand for land for industrial usage, infrastructure, and residence. However, the engineering properties of such soils are challenging, and often difficult to predict due to their inhomogeneity and a lack of information about the initial or current parameters. Double porosity mining waste landfills in Northern Bohemia in the Czech Republic were studied in this project. There, decades of open-cast mining of brown coal have left vast areas of land affected by the waste overburden that has been removed and dumped in old mining pits. Redevelopment of areas affected by mining sometimes requires construction on old overburden waste spoil heaps, which consist primarily of lumps of overconsolidated clay and are therefore characterised by a double porosity soil structure. The loading response on these clayfills entails large absolute and relative deformations, which means that ground improvement is normally needed before construction begins, to ensure that both stability and service limit state requirements are met. The primary aim of this research was a comparison, through physical modelling, of ground improvement techniques on double porosity clay landfills. A secondary objective was to contribute to the understanding of the material behaviour governing response to loading and other processes on double porosity soil.

Inhalt

Centrifuge modelling of ground improvement for double porosity clay 1
Imprint 4
Foreword 5
Acknowledgments 7
Contents 9
Kurzfassung 15
Abstract 17
1 Introduction 19
1.0 Motivation 19
1.1 Context of research 20
1.2 Aims, methodology, and structure of the study 21
2 Literature review 23
2.0 The challenge: landfills and ground improvement 23
2.1 Double porosity soil 29
2.2 Mining waste landfills in the Czech Republic 37
2.3 Centrifuge modelling 42
3 Laboratory testing 55
3.0 Material 55
3.1 Parameter tests 55
3.2 Mini centrifuge tests 57
3.3 Material preparation method for large centrifuge tests 63
3.4 Oedometer testing to establish effect of saturation ratio on onedimensional compression 66
3.5 Summary 71
4 Centrifuge testing 73
4.0 Introduction 73
4.1 Series 1: Scoping tests 89
4.2 Series 2: Embankments 116
4.3 Series 3: Sand compaction piles (SCPs) 134
4.4 Series 4: Dynamic compaction 169
4.5 Discussion of centrifuge modelling challenges 195
5 Discussion 199
5.0 Introduction 199
5.1 Implications for the soil structure 199
5.2 Foundation tests 207
5.3 Effect of ground improvement measures 211
5.4 Performance in practice - recommendations 215
6 Conclusions and outlook 217
6.0 Summary of experimental conclusions 217
6.1 Outlook and recommendations 220
7 References 223
8 Appendix 0: Lists of Figures and Symbols 229
8.0 List of Figures 229
8.1 List of Symbols 239
9 Appendix 1: Data plots 240
9.0 Series 1 240
9.1 Series 2 243
9.2 Series 3 246
9.3 Series 4 256
9.4 Chapter 5 261
10 Appendix 2: Positions of PPTs after centrifuge tests 264
Curriculum Vitae 267

Produkt-Details

• Erscheint lt. Verlag: 1.11.2015
• Reihe/Serie: Veröffentlichungen des Instituts für Geotechnik (IGT) der ETH Zürich
• Verlagsort: Zürich
• Sprache: englisch
• Themenwelt: Technik ► Bauwesen
• Schlagworte: Altlasten • Bodenverbesserung • Braunkohlebergbau • Tonboden
• ISBN-10: 3-7281-3652-2 / 3728136522
• ISBN-13: 978-3-7281-3652-7 / 9783728136527