CONTENTS 1.Introduction 2.Design Models for Underground Structures 3.Geotechnical Investigations 4.Instrumentation design 5.Feedback Analysis 百年同濟2 TONGILUNIVERSITY
2 1. Introduction 2. Design Models for Underground Structures 3. Geotechnical Investigations 4. Instrumentation design 5. Feedback Analysis CONTENTS
1.Introduction 1.1 Feature of Underground Engineering Theoretical Analysis Design of underground structure (different from above- ground structures,for the Experiences complicated geological conditions and interactions in structure-ground system) In-situ Measurement 百年同海3 TONGII UNIVERSITY
3 Design of an underground structure (different from above-ground structures, for the complicated geological conditions and interactions in structure-ground system) 1. Introduction 1.1 Feature of Underground Engineering Design of underground structure (different from aboveground structures, for the complicated geological conditions and interactions in structure-ground system) Theoretical Analysis Experiences In-situ Measurement
1.Introduction 1.2 Design procedure Geology Investigation Lab and In-Situ Tests Geotechnical Properties ↓ Designer Experience Excavation Method and Support System Structural Model and Design Predictions No 0k? Yes Construction 反年日源4 TONGILUNIVERSITY
4 Geology Lab and In-Situ Tests Designer Experience Investigation Geotechnical Properties Excavation Method and Support System Structural Model and Design Predictions Ok? Construction Yes No 1. Introduction 1.2 Design procedure
1.Introduction 1.3 Design Principle Principle 1 The ground constitutes the main structural element of a tunnel Principle 1.1 Minimise disturbance to the ground during excavation or even increase its strength Principle 1.2 Allow displacements to mobilise its support capacity,leading to the ring effect Principle 1.3 Prevent excessive displacements to avoid loosening and consequently strength loss 百年同濟5 TONGII UNIVERSITY
5 1.3 Design Principle Principle 1 The ground constitutes the main structural element of a tunnel Principle 1.1 Minimise disturbance to the ground during excavation or even increase its strength Principle 1.2 Allow displacements to mobilise its support capacity, leading to the ring effect Principle 1.3 Prevent excessive displacements to avoid loosening and consequently strength loss 1. Introduction
1.Introduction 1.3 Design Principle Principle 2 Selection of an optimum support system,including support type, installation procedure and time,strength and stiffness Principle 2.1 Ring closure needed for support mobilisation Principle 2.2 Intimate contact between ground and support Principle 2.3 Inner support ring has to behave as a thin-walled shell,maximising normal stresses and minimising moments(avoiding internal shear) Principle 2.4 Support capacity increasing has to be done by reinforcement(steel sets,anchors etc.)rather than by cross-section thickening 百年同 *6
6 Principle 2 Selection of an optimum support system, including support type, installation procedure and time, strength and stiffness Principle 2.1 Ring closure needed for support mobilisation Principle 2.2 Intimate contact between ground and support Principle 2.3 Inner support ring has to behave as a thin-walled shell, maximising normal stresses and minimising moments (avoiding internal shear) Principle 2.4 Support capacity increasing has to be done by reinforcement (steel sets, anchors etc.) rather than by cross-section thickening 1. Introduction 1.3 Design Principle