CSP115B - Week 7 Tunnels PDF

Construction Principles CSP115B (Week 7 – Tunnels) Introduction to Tunnel Engineering Tunnel engineering is a specialized field of civil engineering that deals with the design, construction, and maintenance of tunnels. Tunnels are underground structures that provide a passageway for transpo...

Construction Principles CSP115B (Week 7 – Tunnels) Introduction to Tunnel Engineering Tunnel engineering is a specialized field of civil engineering that deals with the design, construction, and maintenance of tunnels. Tunnels are underground structures that provide a passageway for transportation, utilities, or other purposes. They can be built using various methods and materials, depending on the geological conditions, tunnel length, and intended use. Faculty of Engineering and the Built Environment Department of Civil Engineering Danville Tunnel Some Examples of tunnels Mont Blanc Tunnel: Year: 1965 Length: 11.6 km (7.2 miles) Diameter: 8.6 m (28.2 ft) Depth: Up to 2,000 m (6,562 ft) Type: Road tunnel through the Alps Faculty of Engineering and the Built Environment Department of Civil Engineering Introduction to Tunnel Engineering A tunnel is a horizontal or near-horizontal passageway that is entirely underground. History: - Tunnel construction dates back to ancient civilizations, with evidence of tunnels built for irrigation, transportation, and military purposes. - The origins of tunnel engineering can be traced back to ancient civilizations, where tunnels were constructed for various purposes such as irrigation, transportation, and military defense. Archaeological evidence reveals that ancient cultures in Egypt, Greece, and Rome built sophisticated tunnel systems, demonstrating early ingenuity and engineering prowess in tunnel construction. - Here's a brief overview: Faculty of Engineering and the Built Environment Department of Civil Engineering History of Tunnel Engineering Ancient Era (3000 BC - 500 AD): - Egyptians built tunnels for tombs and temples (e.g., Great Pyramid of Giza). - Greeks and Romans constructed tunnels for aqueducts, sewers, and military purposes. Medieval Era (500 - 1500 AD): - Tunnel construction declined, but some tunnels were built for castles and monasteries. Renaissance Era (1500 - 1700 AD): - Tunnel engineering revived, with the construction of canals and mines. Faculty of Engineering and the Built Environment Department of Civil Engineering History of Tunnel Engineering Industrial Era (1700 - 1900 AD): - Development of steam-powered machinery and explosives enabled larger- scale tunnel projects. - Construction of railroads, highways, and utilities drove tunnel engineering innovation. Modern Era (1900 - present): - Advancements in materials, machinery, and technology enabled longer, deeper, and more complex tunnels. - Development of new techniques, such as cut-and-cover, bored tunnels, and immersed tubes. Faculty of Engineering and the Built Environment Department of Civil Engineering History of Tunnel Engineering Notable milestones in tunnel engineering history include: - 1825: First railway tunnel (Liverpool and Manchester Railway) - 1863: First underground railway (London Underground) - 1870: First trans-alpine tunnel (Mont Cenis Tunnel) - 1880: First subway tunnel (New York City Subway) - 1900s: Development of electric tunnel boring machines (TBMs) - 1950s: First undersea tunnel (Channel Tunnel precursor) - 1980s: Development of modern TBMs and advanced tunneling techniques. Faculty of Engineering and the Built Environment Department of Civil Engineering History of Tunnel Engineering Throughout history, tunnel engineering has been shaped by advances in technology, materials, and societal needs, enabling the construction of increasingly complex and ambitious tunnel projects. Faculty of Engineering and the Built Environment Department of Civil Engineering Key Aspects of Tunnel Engineering 1. Geology and Site Investigation: Understanding the geological conditions of the tunnel route, including soil and rock types, groundwater levels, and potential hazards like fault lines or cavities. Conducting site investigations, such as boreholes, geophysical surveys, and laboratory tests, to gather data for design and construction. 2. Tunnel Design: Determining the tunnel's shape, size, and alignment based on factors like geology, hydrology, and intended use. Selecting appropriate tunnel linings, such as concrete, steel, or shotcrete, to ensure structural integrity and durability. Faculty of Engineering and the Built Environment Department of Civil Engineering Key Aspects of Tunnel Engineering 3. Construction Methods: Drilling and Blasting (D&B): using explosives to break up rock and then removing debris. Tunnel Boring Machines (TBMs): mechanical excavation using rotating cutting wheels. Cut-and-Cover: excavating from the surface and then covering with a lid. Immersed Tubes: constructing pre-fabricated tunnel sections and sinking them into place. 4. Materials and Linings: Concrete: cast-in-place or precast segments for tunnel linings. Steel: used for tunnel linings, supports, and reinforcement. Shotcrete: sprayed concrete for tunnel linings and repairs. Faculty of Engineering and the Built Environment Department of Civil Engineering Key Aspects of Tunnel Engineering 7. Maintenance and Rehabilitation: Regular inspections to detect potential issues. Performing maintenance tasks like cleaning, repairs, and replacements. Rehabilitating or upgrading tunnels as needed to extend their lifespan. Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods a) Drilling and Blasting (D&B): Uses explosives to break up rock, which is then removed by mechanical means. Suitable for hard rock, but can be slow and generates vibrations. b) Tunnel Boring Machines (TBMs): Mechanical excavation using rotating cutting wheels. Fast and efficient, but high capital costs and limited flexibility. Types: - Earth Pressure Balance (EPB) TBMs - Slurry Shield TBMs - Open-Face TBMs Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods Drill and Blast Faculty of Engineering and the Built Environment Department of Civil Engineering  Tunnel Boring Machines (TBMs) Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods c) Cut-and-Cover: Excavates from the surface, then covers with a lid. Suitable for shallow tunnels, but can be disruptive to surface activities. d) Immersed Tubes: Constructs pre-fabricated tunnel sections, then sinks them into place. Used for underwater tunnels or where surface disruption must be minimized. e) Hand Mining: Labour-intensive method using hand tools and small machinery. Suitable for small-scale tunnels or where access is limited. Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods f) Mechanized Cut-and-Cover: Combines mechanical excavation with cut-and-cover techniques. Faster than traditional cut-and-cover, but still surface-disruptive. g) Pilot Tube Microtunneling: Uses a small, remotely controlled machine to bore a pilot tunnel. Suitable for small-diameter tunnels and accurate alignment. h) Pipe Jacking: Pushes pre-fabricated pipes through the soil using hydraulic rams. Used for small-diameter tunnels, like utility pipes. Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods Pipejacking Microtunelling Faculty of Engineering and the Built Environment Department of Civil Engineering Tunnel Engineering Methods i) Box Jacking: Similar to pipe jacking, but uses larger, box-shaped sections. Suitable for larger tunnels, like subway stations. Each method has its advantages and limitations, and the choice of tunneling method depends on factors like geology, tunnel size, and environmental concerns. Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels i. Geology: - Rock type and strength - Soil composition and density - Groundwater levels and flow - Fault lines and seismic activity. ii. Tunnel Purpose and Use: - Transportation (highway, railway, pedestrian) - Utility (water, sewage, gas, electricity) - Mining or excavation - Military or defense Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels iii. Tunnel Alignment and Profile: - Horizontal and vertical curves - Gradient and slope - Tunnel length and depth iv. Tunnel Size and Shape: - Diameter or width - Height or clearance - Cross-sectional shape (circular, rectangular, etc.) Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels v. Materials and Linings: - Concrete, steel, or composite materials - Shotcrete, cast-in-place, or precast segments - Waterproofing and drainage systems vi. Hydrology and Water Management: - Groundwater control and drainage - Surface water runoff and management - Flood protection and emergency response Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels vii. Ventilation and Air Quality: - Fresh air supply and exhaust systems - Air quality monitoring and control - Emergency ventilation and evacuation plans viii. Lighting and Electrical Systems: - Lighting design and installation - Power supply and distribution - Communication and signaling systems Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels ix. Safety and Emergency Response: - Fire protection and suppression systems - Emergency response plans and equipment - Safety signage and communication systems x. Environmental Impact and Sustainability: - Minimizing environmental disruption - Sustainable materials and practices - Long-term maintenance and rehabilitation plans Faculty of Engineering and the Built Environment Department of Civil Engineering Factors Considered in the Design of Tunnels xi. Constructability and Logistics: - Construction methods and sequencing - Site access and logistics - Material transportation and storage xii. Cost and Budget: - Initial construction costs - Long-term maintenance and operation costs - Life-cycle cost analysis and optimization Faculty of Engineering and the Built Environment Department of Civil Engineering Support Systems and Linings used in Tunnel Engineering Support systems and linings are crucial components in tunnel engineering, ensuring the stability and durability of the tunnel structure. a) Support Systems: - Rock bolts: Steel bolts anchored into the rock to prevent rockfall and stabilize the tunnel. - Steel ribs: Curved or straight steel beams providing additional support to the tunnel. - Shotcrete: A layer of sprayed concrete to stabilize the rock and prevent erosion. - Steel mesh: A grid of steel wires to reinforce the shotcrete and prevent rockfall. - Timber supports: Wooden beams or props used in weaker rock or soil conditions. Faculty of Engineering and the Built Environment Department of Civil Engineering Support Systems and Linings used in Tunnel Engineering b) Linings: - Cast-in-place concrete: Concrete poured directly into the tunnel to create a smooth, durable lining. - Precast concrete segments: Pre-fabricated concrete sections assembled in the tunnel to form the lining. - Steel linings: Thin steel plates or sheets used to line the tunnel, often in combination with concrete. - Composite linings: Combination of materials, such as steel and concrete, to achieve optimal strength and durability. - Membrane linings: Waterproof membranes to prevent water ingress and protect the tunnel. Faculty of Engineering and the Built Environment Department of Civil Engineering Support Systems and Linings used in Tunnel Engineering c) Other Support and Lining Systems: - Grouting: Filling gaps and voids with grout to prevent water ingress and stabilize the rock. - Anchors: Post-tensioned anchors to secure the tunnel lining to the surrounding rock. - Nailing: Installing nails or pins to secure the rock and prevent rockfall. - Mesh drapes: Hanging mesh screens to catch loose rock and debris. - Sprayed concrete arches: Building arches using sprayed concrete to add additional support. Faculty of Engineering and the Built Environment Department of Civil Engineering Support Systems and Linings used in Tunnel Engineering These support systems and linings work together to ensure the stability, safety, and longevity of the tunnel, protecting users and maintaining the structural integrity of the tunnel. Faculty of Engineering and the Built Environment Department of Civil Engineering Some Examples of tunnels - Channel Tunnel (Eurotunnel): - Gotthard Base Tunnel: - Year: 1994 - Year: 2016 - Length: 50 km (31 miles) - Length: 57 km (35.4 miles) - Diameter: 7.6 m (25 ft) - Diameter: 8.8 m (29 ft) - Depth: Up to 40 m (131 ft) - Depth: Up to 2,300 m (7,500 ft) - Type: Undersea tunnel for rail - Type: Railway tunnel through the transport. Alps. - Country: England - France - Country: Switzerland Faculty of Engineering and the Built Environment Department of Civil Engineering Some Examples of tunnels - Seikan Tunnel: - Big Dig Tunnel: - Year: 1988 - Year: 2007 - Length: 53.8 km (33.5 miles) - Length: 5.6 km (3.5 miles) - Diameter: 9.1 m (30 ft) - Diameter: 8.5 m (28 ft) - Depth: Up to 240 m (787 ft) - Depth: Up to 30 m (100 ft) - Type: Undersea tunnel for rail - Type: Highway tunnel transport. - Country: Boston USA - Country: Japan Faculty of Engineering and the Built Environment Department of Civil Engineering Seikan Tunnel Some Examples of tunnels Mont Blanc Tunnel: Year: 1965 Length: 11.6 km (7.2 miles) Diameter: 8.6 m (28.2 ft) Depth: Up to 2,000 m (6,562 ft) Type: Road tunnel through the Alps Faculty of Engineering and the Built Environment Department of Civil Engineering Some Examples of tunnels - London Underground Tunnels: - Gibraltar Tunnel: - Year: Various (1863-2020) - Year: 1967 - Length: Up to 12 km (7.5 miles) - Length: 1.8 km (1.1 miles) - Diameter: 3.5-4.2 m (11.5-13.8 ft) - Diameter: 6.5 m (21.3 ft) - Depth: Up to 30 m (100 ft) - Depth: Up to 30 m (100 ft) - Type: Subway tunnels - Type: Road tunnel - Country: London England - Country: Spain Faculty of Engineering and the Built Environment Department of Civil Engineering London Underground Tunnels Some Examples of tunnels Mont Blanc Tunnel: Year: 1965 Length: 11.6 km (7.2 miles) Diameter: 8.6 m (28.2 ft) Depth: Up to 2,000 m (6,562 ft) Type: Road tunnel through the Alps Faculty of Engineering and the Built Environment Department of Civil Engineering Some Examples of tunnels - Mont Blanc Tunnel: - Year: 1965 - Length: 11.6 km (7.2 miles) - Diameter: 8.6 m (28.2 ft) - Depth: Up to 2,000 m (6,562 ft) - Type: Road tunnel through the Alps - Country: Italy Faculty of Engineering and the Built Environment Department of Civil Engineering Mont Blanc Tunnel Some Examples of tunnels Mont Blanc Tunnel: Year: 1965 Length: 11.6 km (7.2 miles) Diameter: 8.6 m (28.2 ft) Depth: Up to 2,000 m (6,562 ft) Type: Road tunnel through the Alps Faculty of Engineering and the Built Environment Department of Civil Engineering