Tunnel Excavation Device Using Perforating Means and Injection
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Solution Overview
Problem
Conventional tunnel excavation devices have poor excavation efficiency and short cutter lifespan due to immediate groove formation and abrasion, leading to increased maintenance costs and prolonged construction times.
Innovation Solution
A tunnel excavation device with a rotatable excavation head featuring perforating means, such as laser drills or wedge-type drills, that forms holes in the bedrock and injects water and liquefied nitrogen to expand and crack the rock, allowing for efficient crushing using cutting or press-type cutters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional tunnel excavation devices form grooves immediately on bedrock surface using central core drill and outer core groove perforating member, then excavation work can proceed, but excavation efficiency is poor and cutter lifespan is short due to immediate crushing
Solution Approach 1:
The patent applies preliminary action by first forming multiple holes on the bedrock surface using a core drill before crushing operations. The holes are formed at predetermined intervals and depths, creating pre-weakened zones in the rock that facilitate subsequent crushing. This preliminary hole formation separates the drilling phase from the crushing phase, allowing cutters to work more efficiently on already-compromised rock structures rather than intact bedrock, thereby extending cutter lifespan while improving excavation efficiency.
Solution Approach 2:
The patent segments the excavation process into distinct phases: hole formation by core drill, water injection into holes, and subsequent crushing by cutters. The bedrock is segmented into multiple hole locations arranged in patterns (circles, ellipses, or irregular shapes), allowing systematic treatment of different rock zones. This segmentation enables controlled water injection into individual holes to create expansion forces that further segment the rock structure before cutter contact.
2Ease of operation
If conventional tunnel excavation devices use mechanical crushing only, then excavation can proceed, but vibrations, noise, and dust are generated reducing working conditions
Solution Approach 1:
The patent introduces water as an intermediary substance injected into the pre-formed holes in the bedrock. This water serves as a mediator that transfers energy from the injection system into the rock structure, creating hydraulic pressure and subsequent freezing expansion forces. This intermediary mechanism enables rock fracture without direct mechanical contact between cutters and intact rock surfaces, significantly reducing vibrations, noise, and dust generation while improving working conditions.
Solution Approach 2:
The patent utilizes phase transitions of water as a key mechanism for rock fragmentation. Water is injected into holes in liquid form, then freezes to ice, undergoing a phase transition that causes volume expansion. This expansion generates powerful forces that crack and fragment the surrounding rock. The phase transition from liquid to solid state provides a clean, controlled method of rock breakdown that avoids the harmful effects of conventional mechanical crushing, including vibrations, noise, and dust.
3Loss of time
If conventional tunnel excavation devices form grooves and crush immediately, then excavation progresses, but construction time is prolonged and maintenance costs increase
Solution Approach 1:
The patent establishes continuity of useful action by creating an integrated system where hole formation, water injection, and crushing operations are performed in a continuous cyclic manner. The core drill forms holes, water is immediately injected, freezing and expansion occur, and crushing follows without interruption. This continuous cycle eliminates idle time between drilling and crushing operations, maximizing productivity and reducing overall construction time while the extended cutter lifespan naturally reduces maintenance costs.
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 vibrations, noise, and dust, increases processing speed, and extends cutter lifespan, enabling longer excavation distances per day and shorter construction periods while minimizing maintenance costs.
Implementation Method 1
injects water and liquefied nitrogen into the holes to allow the bedrock to be easily crushed using a property of water which expands upon freezing
Implementation Method 2
a property of water which expands upon freezing
Implementation Method 3
perforating means, such as laser drills or wedge-type drills, that forms holes in the bedrock
Data Source
AI summary
The invention relates to a tunnel excavation device, which includes an excavation head, a main body on which the excavation head is rotatably mounted, a motor provided in the main body and rotates the excavation head, and a controller for controlling the motor, wherein the excavation head includes a perforating means formed by maintaining a predetermined interval from the center of a body part, which has a front surface formed in the shape of a circular plate, to the outer surface of the body part, an injection means for injecting water and liquid nitrogen into the hole formed by the perforating means, and a plurality of cutters provided on the surface of the main body for crushing the bedrock.