Geotechnical Lessons Learnt―Building and Transport Infrastructure Projects: Proceedings of the 2021 AGS Sydney Annual Symposium

Description

This book contains accepted papers submitted and peer-reviewed for the 25th Annual Symposium organised by the Sydney Chapter of the Australian Geomechanics Society (AGS). The objective is to bring together the key stakeholders of the Australian geological and geotechnical community. It showcases state-of-the-art practices, new research findings, and case histories that demonstrate geotechnical advances and challenges in building and transport infrastructure. It focuses on geotechnical aspects of smart solutions and improvements in geotechnical approaches for transport infrastructure projects, advances in tunnel design and construction, and geotechnical challenges in design and construction – case histories and lessons learnt. This volume will be a useful guide to those in academia and industry working in the fields of geotechnical engineering. Preface Australian Geomechanics Society Contents About the Editors Smart Solutions in a Circular Economy for Advancing Railroad Design and Construction Using Recycled Materials 1 Introduction 2 Granular Mixtures for Railway Subballast/Capping Layer 2.1 Application Concept 2.2 Testing Program 2.3 Results and Discussion 3 Using Under Ballast Mats (UBM) 3.1 Application Concept 3.2 Testing Program 3.3 Performance of Track with UBM 4 Tyre-Cell Reinforced Railway Capping Layer 4.1 Application Concept 4.2 Analytical Studies 4.3 Experimental Studies 5 Practical Applications 5.1 Singleton Track with Shockmats (UBM) 5.2 Chullora Track Design 5.3 Port Kembla Outer Harbour Reclamation 5.4 Moss Vale Road, Kangaroo Valley 6 Conclusions References Geotechnical Designs Gone Wrong—Lessons Learnt 1 Introduction 2 Frequency of Different Types of Failures from Author’s Experience 3 Shoring and Retaining Wall Problems 4 Earthworks Problems 4.1 Creep and Hydro-Consolidation 4.2 Shrink-Swell Issues 5 Latent Condition Claims 6 JET Grouting Induced Ground Movement 7 Soft Soil Post-construction Settlement Issues 8 Conclusions References The Challenges of Field Measurement of Suction Within Free-Standing Mainline Railway Embankments 1 Introduction 2 Suction 2.1 Concepts—Simplified Picture 2.2 Reliance on Suction and the Challenges 2.3 Measurement of Suction 2.4 Interim Notes 3 Installation of Suction Sensors at Depth Within Free-Standing Embankment 4 Results to Date 4.1 ‘Early Days’ Results 4.2 Results Post Rainfall of Late October 2020 5 Conclusion References Excessive Post-construction Settlement of Improved Ground—Case Histories 1 Introduction 2 Case Histories 2.1 Case History 1 2.2 Case History 2 2.3 Case History 3 2.4 Case History 4 2.5 Case History 5 3 Lessons Learnt and Conclusions References A Smart Geotechnical and Geological Approach for Future Building and Transport Infrastructure Projects 1 Introduction 2 Approach 3 Discussion 3.1 Case Study 1—British Geological Survey 3.2 Case Study 2—Geological Survey of the Netherlands 4 Conclusions References Deep Wet Soil Mixing Columns Ground Treatment Technique-Lesson Learnt from Project 1 Introduction 2 Site Description and Geology 3 Project Design Criteria 4 Ground Treatment Design 5 Instrumentation and Monitoring Results 5.1 Settlement Results 5.2 Lateral Movement Results 5.3 Pore Pressure Responses 6 Construction Quality Control 6.1 Coring and UCS Results 6.2 CPT Test Results 6.3 Column Head Exposure 7 Lesson Learnt 7.1 Use of Recycled WSM Waste 7.2 WSM Mixing, Trial and Construction Issues 7.3 WSM Testing and Deviation from R224 8 Conclusions References Improvements to the Observational Method in New South Wales Road Tunnel Construction 1 Introduction 2 Background 2.1 The Observational Method 2.2 Sydney Tunnelling Boom 2.3 Development of the Observational Method 2.4 Use of the Observational Method in Sydney Tunnels 2.5 Workplace Health and Safety 3 Permit to Tunnel 3.1 Background 3.2 PTT Process 3.3 Limitations 3.4 Current Trends 4 Improvements to the Observational Method in New South Wales Tunnel Construction 5 Conclusions References Precision Tunnelling Under Heritage Building in Sydney CBD 1 Introduction 1.1 Pedestrian Tunnel Overview 2 Site Constraints 2.1 50 Martin Place 2.2 Metro Martin Place Caverns 2.3 Sydney Water Sewer 3 Geology and Ground Characterisation 3.1 Identified conditions 3.2 Groundwater 3.3 Geotechnical Design Parameters 4 Considerations in Design and Construction Due to MCB 5 Numerical Modelling 5.1 Model Results 6 Tunnel Support 7 Construction 7.1 Permit to Tunnel 7.2 Sequence 7.3 Encountered MCB’s 7.4 Observations 8 Conclusions References Design of Complex Permanent Tunnel Linings at Sydney Metro’s Victoria Cross Station 1 Introduction 2 Ground Conditions 3 Groundwater 4 Intersection Geometry 5 Design Criteria 6 Ground Loads 6.1 Geological Structure Checks 6.2 Empirical Methods 6.3 Numerical Analysis 6.4 Adopted Loads 7 3D Numerical Analysis 7.1 Material Properties 7.2 Finite Element Modelling 7.3 Post-processing 8 Design Outcomes 9 Conclusions References Differentiating Fill and Natural Soft Clays—The Value of Desktop Studies in Building a Geological Model 1 Introduction 2 Ground Investigation 3 Geological and Anthropogenic History 3.1 Tertiary 3.2 Pleistocene 3.3 Holocene 3.4 Anthropocene 4 Ground Model 5 Differentiating Fill and Natural Soft Clays 5.1 Comparison of Units 5.2 Considering Peripheral Information 5.3 Unit Validation 5.4 Discussion 6 Conclusions References Geotechnical Challenges in Design and Construction of Bridge Foundations and Approaches in Hilly Granite Formation 1 Introduction 2 Project Background 3 Detailed Design Outcome of Key Elements 3.1 Main Bridge and Abutments 3.2 Northern and Southern Approaches 3.3 Slope Stabilisation Works 3.4 New Cut Batter Design 4 Construction Stage Challenges 4.1 Slope Stabilisation Works 4.2 Pier 1 Subgrade 4.3 Pier 2 Redesign 4.4 Abutment B and Approach Retaining Wall 5 Construction Stage Photos and Lessons Learnt 6 Conclusions References Shear Strength Testing for Geotechnical Structures 1 Introduction 2 Material Properties 2.1 Generic Material Properties 2.2 Site Specific Material Properties 3 Laboratory Testing 3.1 Common Laboratory Test Methods 3.2 Unconfined Compression Strength Testing 3.3 Direct Shear Test 3.4 Triaxial Test 3.5 Large Scale Triaxial Test 4 Know Your Materials 5 Conclusions References