Shield Machine Entrance Sealing Method
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Solution Overview
Problem
Existing shield methods for tunnel construction using shield machines often result in excavated soil and pieces getting stuck in the sealing member, leading to inefficient water-stopping and increased construction expenses due to the need for complex equipment and pressurizing devices.
Innovation Solution
A shield method involving a first cylindrical frame for the shield machine entry, followed by excavation of a horizontal hole with segment addition, temporary water stoppage, removal of excavated soil and pieces, and coupling of a second cylindrical frame with a sealing member to prevent sticking, while maintaining internal pressure equal to or higher than underground pressure to prevent wall cracking and water leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the shield machine excavates the earth retaining wall of the shaft to advance, then the tunnel construction progresses, but excavated soil and pieces get stuck between the sealing member and the shield machine or segments
Solution Approach 1:
The patent applies preliminary action by stopping water from the gap between the entrance and shield machine before removing excavated soil and pieces. This preliminary water stoppage prevents soil and pieces from being carried by water flow into the sealing member area, ensuring the sealing member remains functional during subsequent cleanup operations.
2Reliability
If complex equipment and pressurizing devices are used to prevent soil sticking, then water-stopping efficiency improves, but construction expenses increase
Solution Approach 1:
The patent applies self-service by using the shield machine's own excavation and movement process to naturally control water flow and soil displacement. The shield machine advances while water is stopped from the gap, allowing the system to self-regulate without requiring external pressurizing devices or complex equipment to prevent soil sticking to the sealing member.
3Reliability
If the sealing member is pressed against the shield machine and segments, then water-stopping function improves, but excavated soil and pieces may get stuck in the sealing member
Solution Approach 1:
The patent applies preliminary action by stopping water from the gap between the entrance and shield machine before the shield machine fully enters and before removing excavated material. This preliminary water cutoff prevents soil and pieces from being washed into the sealing member area, ensuring the sealing member remains clean and functional when it contacts the shield machine and segments.
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 ensures effective water-stopping, reduces construction expenses, and enhances work safety by preventing soil and piece sticking in the sealing member, while maintaining structural integrity and controlling water ingress.
Implementation Method 1
The sealing member comes into contact with the outer circumferential surface of the shield machine when the shield machine excavates the earth retaining wall of the shaft and enters the entrance frame. When the shield machine further moves forward and goes beyond the sealing member so that segments as an outer shell of the tunnel are disposed, the sealing member comes into contact with an outer circumferential surface of the segments.
Implementation Method 2
When the shield machine excavates the ground and the earth retaining wall of the arrival shaft to advance
Implementation Method 3
If the water pressure in the soil E is high, spring water enters the inside of the cylinder body 5
Data Source
AI summary
A shield method includes the steps: providing a first cylindrical frame 31 at a position where an entrance 12 is to be formed in an inner surface of an earth retaining wall 11 of a shaft 1; excavating a horizontal hole 5 in the underground by a shield machine 2, and sequentially adding and building, in the excavation direction, a plurality of segments 4 on an inner diameter side of the horizontal hole 5 while forming the entrance 12 in the shaft 1; temporarily stopping water from a gap between the entrance 12 and the shield machine 2, and removing excavated soil and pieces 6 that enter the first cylindrical frame 31 as the entrance 12 is formed; and coupling a second cylindrical frame 32 having a sealing member 35 attached thereto to an inner open end of the first cylindrical frame 31.