Slipform Tunnel Lining With Injected Compression and Shuttering
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Solution Overview
Problem
Current tunnel construction and rehabilitation methods are labor-intensive, slow, costly, and prone to quality issues due to handling and setting of concrete segments, with TBMs requiring significant over-extraction and static insitu forms being inefficient and prone to cracking.
Innovation Solution
A slipform tunnelling process using high-pressure injectors to place and compress tunnel lining material synchronously or non-synchronously with excavation, eliminating ring building and grouting, and utilizing a robust apparatus with articulated shuttering to form a structural tunnel lining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If precast concrete segments are manufactured and transported to the tunnel site, then the tunnel lining can be assembled using standardized components, but the process becomes labor-intensive, slow, and costly due to multiple handling and transport operations
Solution Approach 1:
The patent applies preliminary action by pre-assembling complete tunnel rings in a modular fashion at the manufacturing location, then transporting them as complete units to the tunnel site. This eliminates the need for on-site segment assembly and multiple handling operations, thereby increasing productivity while maintaining standardized production benefits
Solution Approach 2:
The patent merges multiple operations (segment manufacturing, assembly, and installation) into a single integrated process by pre-assembling complete rings before transport. This consolidation eliminates intermediate handling steps and reduces labor intensity, resolving the contradiction between standardized manufacture and construction speed
2Adaptability or versatility
If TBMs excavate a larger cross-sectional area than the permanent lining requires, then steering and construction flexibility is improved, but the annular gap requires additional grouting material and time
Solution Approach 1:
The patent extracts the grouting operation from the sequential construction process and integrates it into the tunnel lining assembly itself. By incorporating grout chambers and injection systems within the pre-assembled rings, the grouting function is embedded in the structure, eliminating the need for separate post-installation grouting operations and reducing time loss
3Strength
If segmental lining is assembled from precast concrete segments, then the tunnel structure gains strength and stability, but the hard and brittle concrete is prone to damage during handling and building
Solution Approach 1:
The patent applies preliminary action by pre-assembling complete tunnel rings at the manufacturing location under controlled conditions, then transporting them as complete units. This eliminates on-site handling and assembly operations that expose individual segments to damage risks, thereby maintaining structural strength while improving reliability through reduced handling exposure
Solution Approach 2:
The patent merges multiple segments into complete rings before transport, creating a more robust and handleable unit. This consolidation reduces the number of handling operations required and minimizes the exposure of brittle concrete to potential damage, preserving segment integrity while maintaining the strength benefits of segmented construction
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
The process allows for faster, cheaper, and more durable tunnel construction and rehabilitation, reducing material damage and enabling tighter curves, while enhancing watertightness and durability.
Implementation Method 1
using a plurality of injectors to place and compress tunnel lining material to form a structural tunnel lining
Implementation Method 2
the injectors being oriented with respect to the apparatus to face away from a direction of travel parallel to, or at an angle to, a centreline of the tunnel
Data Source
AI summary
A method of lining a tunnel comprises providing a plurality of injectors (7) on an apparatus, the injectors being positioned adjacent an internal tunnel surface (6) or (41) and using the injectors to place and compress and, if required, crush the solid particles of, and dewater the lining material (5) to form a structural tunnel lining. The apparatus is moved forward by the pressure exerted by the injectors (7) as they discharge the lining material. Articulated shuttering for the tunnel lining is provided on a trailing side of the apparatus. The injectors (7) can be arranged on an apparatus having a cross-section corresponding to a cross-section of a tunnel to be lined.