Bypass Tunnel Construction via TBM Slurry Excavation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The construction of underground transport infrastructures, particularly bypass tunnels in urban and metropolitan contexts, faces challenges due to complex soil conditions, limited mechanization, and safety concerns, leading to difficulties in excavation and impermeabilization, which result in restricted work environments, sensitivity to soil consolidation, and risks associated with imperfect impermeabilization.
Innovation Solution
The procedure involves using mechanized tunnel boring machines with a slurry system and impermeabilization structures to excavate and construct bypass tunnels in a controlled and safe manner, ensuring structural stability and minimizing environmental impact, by employing tunnel boring machines and a slurry system to excavate bypass tunnels and precast segments, while maintaining the integrity of the existing pipes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional excavation methods are used for bypass tunnels, then flexibility in complex soil conditions is maintained, but construction time and costs increase significantly
Solution Approach 1:
The patent applies multi-functionality by integrating multiple operations into a single mechanized system. The tunnel boring machine performs excavation, muck removal, and lining installation simultaneously, while the slurry system handles both excavation support and soil removal. This consolidates what would traditionally require separate operations into one coordinated system, resolving the contradiction between productivity improvement and device complexity.
Solution Approach 2:
The patent utilizes hydraulic and pneumatic systems extensively through the slurry circulation system. The slurry is pumped under pressure to the excavation face, provides support, and carries excavated material back to the surface through the same machine. This hydraulic-pneumatic approach enables automated, continuous operation that dramatically increases construction speed while managing the complexity through integrated system design.
2Reliability
If pre-consolidation treatments are performed to improve soil mechanical characteristics, then excavation safety is improved, but construction time and work complexity increase
Solution Approach 1:
The patent applies preliminary action through the slurry system that pre-supports the excavation face before actual tunneling begins. The slurry is introduced in advance to stabilize the soil and prevent collapses during the excavation process, eliminating the need for separate pre-consolidation treatments and reducing overall construction time while maintaining safety.
Solution Approach 2:
The slurry acts as an intermediary substance between the excavation machine and the soil. It provides immediate structural support to the excavated material, enabling safe excavation without requiring time-consuming pre-consolidation treatments. The slurry mediates the interaction between the machine and unstable soil, allowing continuous operation and reducing construction time.
3Productivity
If mechanized tunnel boring machines with slurry systems are used, then construction efficiency and safety are improved, but system complexity and initial costs increase
Solution Approach 1:
The patent merges multiple separate systems into one integrated tunnel boring machine. The excavation mechanism, slurry circulation system, muck removal apparatus, and lining installation equipment are combined into a single coordinated machine. This consolidation improves construction efficiency through continuous operation while managing complexity through integrated design and centralized control.
Solution Approach 2:
The tunnel boring machine is designed to be self-sufficient, performing excavation, support, material removal, and lining installation without requiring external intervention for each operation. The slurry system serves itself by circulating continuously, and the machine maintains its own operational parameters, reducing the need for complex external support systems and simplifying overall project management despite the advanced technology involved.
4Reliability
If traditional excavation methods are used, then equipment simplicity is maintained, but worker safety and environmental protection are compromised
Solution Approach 1:
The patent uses precast concrete segments as copies or replicas of the desired tunnel lining structure. These standardized segments are manufactured off-site with precise geometries and structural properties, then assembled in the tunnel. This copying approach ensures consistent safety standards while reducing the complexity of on-site formwork and reinforcement operations, as the segments are designed and tested beforehand.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach standardizes bypass tunnel geometries, enhances safety and quality, reduces construction time, and lowers costs by enabling efficient and controlled excavation and impermeabilization, thereby maximizing worker safety and minimizing environmental impact.
Implementation Method 1
The slurry system is used to excavate the bypass tunnel and remove the excavated material through the tunnel boring machine
Data Source
AI summary
The procedure for the construction of underground transport infrastructures, comprises the steps of:excavating an underground transport tunnel comprising a first pipe and a second pipe substantially parallel to one another;making a bypass tunnel connecting the first pipe and the second pipe which comprises the sub-steps of:introducing a launching chamber along the first pipe up to a first predefined position chosen along the longitudinal direction of the first pipe, the launching chamber being able to launch a tunnel boring machine;introducing an arrival chamber along the second pipe up to a second predefined position chosen along the longitudinal direction of the second pipe, the arrival chamber being able to receive the tunnel boring machine;excavating the bypass tunnel making the tunnel boring machine move forward from the launching chamber to the arrival chamber along a direction transversal to the first pipe and to the second pipe.