Noise-Abating Pile with Viscous Damping for Underwater Sound Isolation
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Solution Overview
Problem
Pile driving in water generates extremely high sound levels, causing environmental disturbances and regulatory challenges, with existing noise mitigation methods like bubble curtains and Temporary Noise Attenuation Piles (TNAP) showing limited effectiveness due to inadequate addressing of sound transmission through sediment.
Innovation Solution
A noise-abating pile design featuring a pile driving shoe with an outer tube and an inner member forming an annular channel, where the pile driver impacts the inner member without directly impacting the outer tube, which is configured to isolate sound propagation through the sediment and water, using a biodegradable or inflatable seal and compressible materials to enhance noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional pile driving methods are used, then construction efficiency is maintained, but underwater noise levels become extremely high causing environmental disturbance
Solution Approach 1:
The patent introduces an intermediary system consisting of a suspension structure with damping elements that mediates between the pile driver and the pile. This intermediary absorbs and dissipates impact energy through viscous damping, reducing the transmission of high-frequency stress waves to the water-sediment interface, thereby lowering underwater noise while maintaining driving capability
Solution Approach 2:
The patent changes the temporal and spectral parameters of the impact force by using viscous dampers that extend the duration of the impact while reducing peak forces. This parameter transformation converts high-intensity short-duration impulses into lower-intensity longer-duration forces, significantly reducing noise radiation to aquatic environments
2Object-affected harmful factors
If viscous dampers are added to reduce noise, then underwater noise levels decrease, but device complexity increases
Solution Approach 1:
The patent employs viscous dampers that function as flexible energy-dissipating elements within the suspension structure. These dampers utilize viscous fluid flow through restricted passages to provide passive damping, achieving noise reduction without requiring active control systems or complex mechanical mechanisms
Solution Approach 2:
The viscous dampers are designed as passive devices that automatically dissipate impact energy through the inherent viscous properties of the damping fluid. The system self-regulates the impact forces without requiring external control, sensors, or power sources, thereby reducing operational complexity while maintaining noise attenuation effectiveness
3Object-affected harmful factors
If impact forces are reduced to protect wildlife, then environmental impact decreases, but pile driving effectiveness is compromised
Solution Approach 1:
The patent segments the force transmission path by introducing a suspension structure with multiple damping elements between the pile driver and the pile. This segmentation allows the impact force to be divided and dissipated in stages, reducing the force transmitted to the pile while maintaining sufficient driving capability through cumulative effect
Solution Approach 2:
The patent employs dynamic damping elements that adapt their resistance based on the impact velocity and force. The viscous dampers provide velocity-dependent damping forces that are high during initial impact to protect wildlife but allow continued force transmission as the pile penetrates the sediment, maintaining driving effectiveness throughout the installation process
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 design significantly reduces underwater noise levels by isolating the sound-propagating Mach cone within the sediment, effectively mitigating the transmission of sound into the water, thereby addressing the limitations of prior art methods.
Implementation Method 1
The pile is configured to be driven by a pile driver impacting the inner member without impacting the outer tube
Implementation Method 2
using a biodegradable or inflatable seal and compressible materials to enhance noise reduction
Implementation Method 3
The design significantly reduces underwater noise levels by isolating the sound-propagating Mach cone within the sediment
Data Source
AI summary
A noise-attenuating pile comprising a pile driving shoe, an outer tube that engages the pile driving shoe, and an inner member that extends through the outer tube and engages the pile driving shoe, wherein the pile is configured to be installed in sediment or other suitable material by driving the inner member with a pile driver, without directly impacting the outer tube, such that the radial outer tube is substantially insulated from the radial expansion waves generated by the pile driver impacting the inner member. In some piles, one of the inner member and the outer tube are removable after installation. In some piles, a seal is provided in a lower end of the channel defined between the inner member and the outer tube, which may be biodegradable, or may be an inflatable bladder, for example.