Blast Hole Arrangement With Water-Bag Isolation in Soft-Weak Rock Tunnels
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Solution Overview
Problem
In rheological soft-weak surrounding rock tunnels, conventional blasting methods lead to uncontrollable vibration, potential safety hazards such as wall caving and collapse, and limited blasting footage, hindering efficient construction progress.
Innovation Solution
A blast hole arrangement structure is employed, dividing the tunnel into sections with specific types of holes (cutting, vibration reduction, and isolation holes) filled with water bags or soft mud, and using controlled charging to minimize shock wave propagation and reduce vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional blasting methods are used in rheological soft-weak surrounding rock tunnels, then the blasting footage can be increased, but the vibration becomes uncontrollable and safety hazards such as wall caving and collapse occur
Solution Approach 1:
The blast holes are segmented into different types: cutting holes for rock breaking, and vibration reduction holes filled with water bags for energy absorption. This segmentation allows the blasting system to achieve both effective rock breaking and vibration control simultaneously
Solution Approach 2:
Water bags are introduced as an intermediary substance in the vibration reduction holes. These water bags absorb and dissipate the shock waves and stress waves generated by blasting, thereby reducing vibration propagation to the surrounding rock while maintaining effective rock breaking in the cutting holes
2Object-affected harmful factors
If careful loose blasting method is adopted to control vibration, then safety hazards are reduced, but the blasting footage becomes small and construction progress slows down
Solution Approach 1:
The blasting system is divided into cutting holes for aggressive rock breaking and vibration reduction holes for controlled energy dissipation. This allows the main cutting holes to operate at higher energy levels for increased footage while the vibration reduction holes manage the harmful effects
Solution Approach 2:
The harmful vibration energy from blasting is converted into a beneficial control mechanism by directing it into water-filled vibration reduction holes. The water absorbs and dissipates the energy that would otherwise cause wall caving and collapse, transforming a harmful effect into a protective feature
3Reliability
If grouting reinforcement is applied to ensure safety, then collapse and wall caving are prevented, but manual and mechanical excavation cannot be carried out and only careful loose blasting can be used
Solution Approach 1:
Vibration reduction holes filled with water bags are prepared in advance alongside the cutting holes. This preliminary arrangement enables the subsequent blasting operation to proceed with both safety and efficiency, as the vibration control mechanism is already in place before the actual rock breaking occurs
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
The structure achieves controlled rock breaking with reduced vibration, protecting the primary support and preventing collapse, enabling efficient excavation of rheological soft-weak surrounding rock tunnels.
Implementation Method 1
excess energy is emptied and absorbed, propagation of shock waves and stress waves around is reduced
Implementation Method 2
propagation of shock waves and stress waves around is reduced
Implementation Method 3
the vibration isolation holes are filled with soft mud; and the purpose is to prevent, absorb, reflect and refract the propagation of the blasting shock waves, stress waves and seismic waves
Implementation Method 4
the vibration isolation holes are filled with soft mud; and the purpose is to prevent, absorb, reflect and refract the propagation of the blasting shock waves, stress waves and seismic waves
Implementation Method 5
rock between every two holes is broken by tensile stress due to reflection and refraction of different interfaces and different media
Data Source
AI summary
A tunnel section subjected to grouting reinforcement is divided into two parts, that is, an upper half section and a lower half section, cutting vibration reduction holes used in coordination with cutting holes are formed in the upper half section, and the cutting vibration reduction holes are not charged and are filled with water bags only. According to the blast hole arrangement structure used for blasting for the rheological soft-weak surrounding rock tunnel of the invention, a cutting blasting effect is improved, excess energy is emptied and absorbed, propagation of shock waves and stress waves around is reduced, and vibration is reduced; and according to the invention, the purpose of forming vibration isolation holes in a tunnel excavation contour line of the upper half section is to prevent, absorb, reflect and refract the propagation of the blasting shock waves, stress waves and seismic waves.