1 Introduction
1.1 Current Development Status of Long Shield Tunnels
1.1.1 The Origin of Shield Tunnels and Their Development Abroad
1.1.2 The Development of Shield Tunnels in China
1.1.3 The Development Trend of Long Shield Tunnels
1.2 Development Status of Shield Tunnel Section Air Shaft and Station Passing Construction Methods
1.2.1 Development Status of Interval Air Shaft Construction
1.2.2 Development Status of Construction Methods for Interval Air Shaft Passing Through Stations
1.3 Current Application Status of Ultra-deep Circular Foundation Pits at Home and Abroad
1.3.1 Development Status of Circular Deep Foundation Pits
1.3.2 Characteristics and Development Trends of Circular Foundation Pit Technology
1.4 Based on the Background of the Engineering Project and the Main Risks of Large-Diameter Shield Tunnel Crossing Circular Air Shafts
1.4.1 Based on the Background of the Engineering Project
1.4.2 Main Risks of Large-Diameter Shield Tunnel Crossing Circular Air Shafts
References
2 Construction Technology of Retaining System for Ultra-deep Circular Air Shaft Foundation Pit in Sensitive Environment Adjacent to River
2.1 Key Technical Issues
2.1.1 High Risk of Foundation Pit Dewatering in Sensitive Environments Near the River
2.1.2 Difficulty in Reinforcement Construction of Ultra-deep Rotary Jet Grouting Piles
2.1.3 Difficulty in Controlling the Construction Quality of Connecting Walls in Ultra-deep Circular Foundation Pits
2.2 Construction Technology of "Pumping Reinjection" for Ultra-deep Circular Air Well in Sensitive Environment of Linjiang
2.2.1 Theoretical Study on "Pumping and Reinjection" of Foundation Pit
2.2.2 Construction Technology of "Pumping and Reinjection" for Foundation Pits
2.2.3 Quality Control of "Pumping and Reinjection" Construction in Foundation Pits
2.3 High-Pressure Rotary Jet Grouting Reinforcement Construction Technology for Ultra-deep Circular Air Shaft in Sensitive Environment of Linjiang
2.3.1 Theoretical Study on Grouting Reinforcement
2.3.2 On-Site Pile Testing
2.3.3 High-Pressure Rotary Jet Grouting Reinforcement Construction Technology
2.3.4 Quality Control of High-Pressure Rotary Jet Grouting Reinforcement Construction
2.3.5 Quality Inspection of High-Pressure Rotary Jet Grouting Reinforcement Construction
2.4 Construction Technology of Cutting Ground Wall for Ultra-deep Circular Air Shaft in Sensitive Environment of Linjiang
2.4.1 Feasibility Study on Machinable Ground Wall Connection
2.4.2 Slot Width Connection Technology
2.4.3 Construction Technology of Machinable Ground Wall
References
3 Underwater Excavation and Underwater Mass Concrete Sealing Construction Technology for Circular Air Shaft
3.1 Key Technical Issues
3.1.1 Difficulty in Underwater Excavation of Ultra-deep Circular Air Shafts
3.1.2 High Technical Requirements for Underwater Concrete Bottom Sealing of Ultra-deep Circular Air Shafts
3.2 General Idea
3.2.1 Underwater Excavation of Ultra-deep Circular Air Shaft
3.2.2 Underwater Pouring of Large-Volume Concrete
3.3 Process Flow and Construction Methods
3.3.1 Underwater Excavation Construction Technology
3.3.2 Safety Assurance Measures for Underwater Excavation
3.3.3 Construction Technology of Underwater Mass Concrete Bottom Sealing
3.3.4 Implementation Effect of Underwater Excavation and Mass Concrete Bottom Sealing
References
4 Key Technologies for Continuous Crossing of Air Shaft with Large Diameter Shield Tunnels
4.1 Key Technical Issues
4.2 Adaptability Improvement Technology for Shield Tunneling Machines
4.2.1 Introduction to the Shield Tunneling Machine for Weisan Road Crossing the River Channel
4.2.2 Configuration of Cutting Tools for the Front Cutterhead of Shield Tunneling Machine Passing Through Meiziz
