TBM Thrust Shell for Simultaneous Excavation and Segment Erection
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Solution Overview
Problem
Conventional tunnel boring machines (TBMs) face inefficiencies in soft ground tunneling due to the need to stop forward movement for segmental lining installation, leading to equal time spent on excavation and segment installation, and in rock tunneling, segment erection often takes longer than excavation.
Innovation Solution
The utilization of a Thrust shell system in conjunction with an expandable ring allows for simultaneous excavation and segment erection, enabling the TBM to continue advancing with minimal interruption as new segmental rings are built within the thrust shell's inner space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional TBM stops forward movement for segment installation, then segmental lining can be properly installed, but tunneling speed decreases and construction period increases
Solution Approach 1:
The patent merges the excavation process and segment installation process into a simultaneous operation. The TBM excavates ground while the segment erector installs segmental lining segments at the same time, eliminating the need to stop excavation for segment installation. This combines two previously sequential operations into one concurrent process, directly resolving the contradiction between installation quality and tunneling speed.
Solution Approach 2:
The patent enables continuous tunneling operation where the TBM advances without interruption. The thrust shell system allows the TBM to maintain forward movement while segments are being erected, ensuring the useful action of excavation continues uninterrupted. This continuity eliminates idle time between excavation cycles and segment installation, maintaining high productivity while ensuring proper segment placement.
2Productivity
If TBM advances continuously without stopping, then tunneling speed increases, but segment installation becomes difficult to perform properly
Solution Approach 1:
The patent employs dynamic systems that adapt during the tunneling process. The thrust shell expands and contracts, the segment erector moves and positions segments dynamically, and the TBM adjusts its advancement rate. This dynamic coordination allows the system to maintain continuous motion while performing the precise, controlled actions needed for proper segment installation, resolving the contradiction between speed and installation quality.
Solution Approach 2:
The patent nests the segment installation process within the continuous excavation process. The segment erector and thrust shell are integrated within the TBM structure, allowing segment erection to occur inside the protective shell while the machine continues to advance. This nested arrangement enables simultaneous operations where segment installation is performed within the confines of the moving TBM system, maintaining both speed and quality.
3Reliability
If segment erection takes longer than excavation in rock tunneling, then final lining is properly installed, but advance cycle time increases
Solution Approach 1:
The patent performs preliminary actions by positioning and installing segmental lining segments during the excavation process itself. Rather than waiting for excavation to complete before beginning segment installation, the system prepares and installs segments in advance, during the excavation phase. This preliminary action eliminates the sequential delay where segment erection would otherwise occur after excavation completes, reducing advance cycle time while ensuring proper lining installation.
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 significantly increases tunneling speed, potentially doubling daily advance rates in soft ground conditions, and reduces construction costs by minimizing the overall construction period.
Implementation Method 1
the TBM thrust cylinders will be pushing against previously installed segmental ring via combination of thrust shell and an expandable ring
Data Source
AI summary
A system and method for simultaneous excavation and segment erection of Tunnel Boring Machine (TBM) by Thrust shell system is an invention in tunnelling industry which will provide possibility of erection of the segmental ring while TBM is excavating and advancing forward with minimum interruption which will result in significantly increasing of the tunneling speed. The increased speed of the tunnelling will be reducing cost of the construction expressively.At this system and method, the TBM thrust cylinders will be pushing against previously installed segmental ring via combination of a thrust shell and an expandable ring while a new segmental ring is being built by TBM's segment erector within the Thrust shell's provided inner space.