Integrated Jacking Pipe Structure for Pressure-Resistant Tunnels
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Solution Overview
Problem
Current pipe jacking methods face challenges in forming durable, pressure-resistant tunnels in high-pressure ground conditions, particularly due to the limitations of labor-intensive welding processes and deformation issues during the jacking process.
Innovation Solution
The integration of a concrete jacking envelope with a metal pipe, featuring a spigot and bell configuration, allows for a sealed, pressure-resistant conduit with reduced need for labor-intensive welding and mitigates deformation through a circumferential clearance, while the concrete envelope protects the metal pipe from soil forces and the load distributor ensures even load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal pipes are welded together to form a sealed conduit, then the tunnel becomes pressure-resistant, but the welding process becomes labor-intensive and time-consuming
Solution Approach 1:
The patent combines the metal pipe and concrete jacking envelope into a single integrated unit, eliminating the need for separate welding operations between metal pipes. The integral formation allows the metal conduit to be formed without labor-intensive welding processes while maintaining pressure-resistance through the integrated structure.
Solution Approach 2:
The patent uses a composite structure combining metal and concrete materials. The metal pipe provides pressure-resistance and conduit functionality, while the concrete envelope provides structural strength and protection. This composite approach allows the system to achieve pressure-resistance without requiring extensive welding of metal components.
2Ease of operation
If multiple jacking pipes are pushed in series to form a tunnel, then the tunnel can be formed through obstacles, but the pipes are subject to deformation from soil forces and jacking pressures
Solution Approach 1:
The patent employs a composite structure where the concrete envelope surrounds and protects the metal pipe. The concrete provides external structural support that resists deformation from soil forces and jacking pressures, while the metal pipe maintains its shape and provides the sealed conduit function. This composite design significantly reduces deformation risks during the jacking process.
Solution Approach 2:
The patent divides the tunnel into multiple segmented jacking pipes that can be pushed in series. Each segment is independently formed with the integrated metal-concrete structure, allowing the tunnel to be constructed through obstacles while each segment maintains its structural integrity and resists deformation from local soil forces and pressures.
3Reliability
If intermediate jacking stations are introduced to reduce pressures in high plasticity ground, then the tunnel formation becomes feasible, but the device complexity increases
Solution Approach 1:
The patent divides the tunnel into multiple segments that can be independently jacked. This segmentation allows intermediate jacking stations to be introduced at specific intervals to reduce pressures in high plasticity ground conditions. Each segment can be independently supported and jacked, making the overall system more manageable despite the added complexity of intermediate stations.
Data Source
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AI summary
An integrated jacking pipe comprising a concrete jacking envelope integrally- formed with and encircling a metal pipe, wherein said metal pipe comprises a spigot protruding from said concrete jacking envelope and a bell whose diameter is larger than a diameter of said spigot.