Vertical Shaft Lining Sequence to Reduce Excavation Instability
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Solution Overview
Problem
The construction of deep and large vertical shafts using the reverse integral inverted-wall method faces challenges such as structural instability, safety risks, and inefficiencies due to the need for precise control over the need for a stable structure, including suspended structures, vibration disturbances, and safety hazards from heavy steel formworks and frequent hoisting operations.
Innovation Solution
A top-down sequential-building construction method for deep and large vertical shafts, involving staged construction from the surface to the contact air channel elevation and then to the vertical shaft bottom, with a lining structure built from bottom to top using single-side cantilever climbing formworks, full-face blasting, and integrated support systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the reverse integral inverted-wall method is used for constructing vertical shafts, then the construction can proceed with suspended structures, but the structure experiences vibration disturbance and instability during excavation
Solution Approach 1:
The patent inverts the conventional construction sequence by constructing the lining structure from bottom to top instead of top to bottom. This allows the lining to be built on a stable foundation rather than being suspended during excavation, eliminating vibration disturbance while maintaining construction feasibility through the inverted sequencing approach
2Ease of manufacture
If large steel formworks are used for constructing the lining structure, then the lining can be built, but the steel formworks are heavy causing frequent hoisting and cross operations with safety risks
Solution Approach 1:
The patent segments the lining construction into multiple sections that can be built sequentially from bottom to top. This segmentation allows smaller, lighter formworks to be used in each section rather than large steel formworks spanning the entire shaft, reducing hoisting frequency and eliminating cross-operation safety risks while maintaining lining construction capability
Solution Approach 2:
By inverting the construction sequence to build from bottom to top, the patent enables the use of smaller, lighter formworks that can be progressively moved upward as construction progresses, rather than requiring heavy steel formworks to be hoisted and positioned from the top down
3Productivity
If the vertical shaft is constructed using traditional methods, then construction can proceed, but there is large interference between processes and many risk sources
Solution Approach 1:
The patent inverts the construction sequence to proceed from bottom to top, which simplifies the construction process by eliminating the need for complex hoisting and cross-operation coordination required in traditional top-down methods. This inversion reduces process interference and risk sources while maintaining construction progress through systematic sequencing
Solution Approach 2:
The patent applies preliminary action by constructing the lining structure in advance from the bottom up, creating a stable foundation and progressively extending the structure as excavation proceeds. This preliminary construction approach simplifies subsequent operations and reduces process complexity compared to traditional methods where structures must be suspended and assembled in complex sequences
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 method reduces structural disturbances, enhances safety, improves construction quality, and reduces risks by minimizing structural dead weight, hoisting frequency, and process interference, while ensuring stable and reliable construction.
Implementation Method 1
The blasting adopts a full-face one-time blasting and a layered integral blasting
Implementation Method 2
A preliminary shotcrete spraying, a steel grid construction, a steel mesh construction, a hollow grouting anchor construction, and a secondary shotcrete spraying are performed
Data Source
AI summary
A top-down sequential-building construction method for deep and large vertical shaft cavern groups is provided. The construction method includes the following steps. A preparation is made for a construction. A vertical shaft locking beam is constructed. A vertical shaft is constructed. A post-construction maintenance is performed. The vertical shaft is constructed through a staged construction, which includes the following steps: S1, constructing from a vertical shaft surface to a contact air channel elevation; S2, constructing a contact air channel; S3, constructing from the contact air channel elevation to a vertical shaft bottom. Both constructing from the vertical shaft surface to the contact air channel elevation and from the contact air channel elevation to the vertical shaft bottom include constructing a lining structure from bottom to top.