KTH Architecture and the Built Environment Geotechnical Aspects of Buildings on Expansive Soils in Kibaha, Tanzania: Preliminary Study CHARLES LUCIAN Licentiate Thesis Division of Soil and Rock Mechanics Department of Civil and Architectural Engineering Royal Institute of Technology Stockholm, Sweden 2006 TRITA-JOB LIC 2011 ISSN 1650-951X Lovingly dedicated to my true treasures in life, my wife and children Geotechnical Aspects of Buildings on Expansive Soils in Kibaha, Tanzania: Preliminary Study TABLE OF CONTENTS TABLE OF CONTENTS...............................................................................................................I ABSTRACT ................................................................................................................................VII PREFACE.................................................................................................................................... IX ACKNOWLEDGEMENTS........................................................................................................ XI NOTATIONS AND SYMBOLS.............................................................................................. XIII 1. INTRODUCTION......................................................................................................................1 1.1 Statement of the Problem ........................................................................................................4 1.2 Objectives of the Study ............................................................................................................6 1.3 Research Methodology.............................................................................................................7 1.4 Limitations ................................................................................................................................8 2. LITERATURE REVIEW..........................................................................................................9 2.1 Introductory Remarks .............................................................................................................9 2.2 Expansive Soils .......................................................................................................................10 2.2.1 Background .......................................................................................................................10 2.2.2 Structure of Expansive Soils .............................................................................................11 2.2.3 Identification of Expansive Soils ......................................................................................12 2.2.4 Climate and Hydrological Conditions...............................................................................38 2.2.5 Conclusions .......................................................................................................................39 2.3 Structures (Super-Structures and Sub-structures).............................................................41 2.3.1 Morphology of Structures .................................................................................................41 2.3.2 The Super-Structure Systems............................................................................................41 2.3.3 The Sub-Structure (Foundation) Systems .........................................................................43 2.3.4 Conclusions .......................................................................................................................43 2.4 Category of Buildings.............................................................................................................44 2.4.1 General ..............................................................................................................................44 2.4.2 Non-Engineered Buildings................................................................................................44 2.4.3 Semi-Engineered Buildings...............................................................................................44 2.4.4 Engineered Buildings ........................................................................................................45 i Table of Contents 2.4.5 Conclusions .......................................................................................................................45 2.5 Construction Materials..........................................................................................................46 2.5.1 General Consideration.......................................................................................................46 2.5.2 Rigid Material ...................................................................................................................46 2.5.3 Flexible Material ...............................................................................................................46 2.5.4 Semi-Rigid Material..........................................................................................................47 2.5.5 Conclusions .......................................................................................................................47 2.6 Damages in Structures...........................................................................................................48 2.6.1 General Remarks...............................................................................................................48 2.6.2 Identification of Damage in Structures .............................................................................49 2.6.3 Allowable Limiting Angular Distortion to Avoid Potential Damage ...............................52 2.6.3 Conclusions .......................................................................................................................53 2.7 Soil-Structure Interaction (SSI)............................................................................................54 2.7.1 General Remarks...............................................................................................................54 2.7.2 Soil-Structure Interaction Modelling ................................................................................56 2.7.3 Conclusions .......................................................................................................................59 2.8 Conclusions of the Literature Review ..................................................................................60 3. PRELIMINARY GEOTECHNICAL FIELD STUDY IN KIBAHA REGION.................61 3.1 Introduction ............................................................................................................................61 3.2 Geological and Geotechnical Characteristics of Soils in Kibaha Region..........................61 3.2.1 Geological Characteristics.................................................................................................61 3.2.2 Geotechnical Description ..................................................................................................62 3.3 Geography and climate conditions of the study area..........................................................64 3.3.1 Geography .........................................................................................................................64 3.3.2 Climatology.......................................................................................................................64 3.4 Field Methodology..................................................................................................................65 3.4.1 General ..............................................................................................................................65 3.4.2 Trial Pits for Block Samples .............................................................................................66 3.5 Field Results............................................................................................................................68 3.5.1 Groundwater......................................................................................................................68 3.5.2 Visual Classification of Soil..............................................................................................68 3.6 Laboratory Tests ....................................................................................................................70 3.6.1 Grain Size Distribution......................................................................................................71 3.6.2 In-Situ Moisture and Density Test ....................................................................................74 3.7.3 Atterberg Limits ................................................................................................................74 3.6.4 Potential Swell Based on Tables and Charts.....................................................................74 3.6.5 Swell Tests ........................................................................................................................82 ii Geotechnical Aspects of Buildings on Expansive Soils in Kibaha, Tanzania: Preliminary Study 3.6.6 X-Ray Diffraction (XRD) Microscopy .............................................................................84 3.7 Swell by Empirical Formulas................................................................................................86 3.8 Conclusions of Preliminary Field Study...............................................................................87 4.