Noise-Attenuating Pile With Elastic Vibration 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 in reducing sound transmission through sediment.

Innovation Solution

A noise-attenuating pile design featuring an outer tube elastically connected to a driving shoe, with an inner member that isolates the outer tube from high-frequency vibrations, and an annular channel filled with compressible material, allowing the outer tube to be pulled into the sediment without direct impact, thereby reducing sound propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional pile driving methods are used, then installation efficiency is maintained, but underwater noise levels become extremely high causing environmental disturbance

Engineering Contradiction:

Improveunderwater noiseVSAvoidinstallation efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The pile system is divided into multiple segments: an outer tube, an inner member, and a driving shoe. The outer tube remains in the water and is elastically connected to the driving shoe, while the inner member is impacted by the hammer. This segmentation allows the outer tube to act as a noise barrier while the inner member transmits driving forces, resolving the contradiction between noise reduction and installation efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The outer tube serves as an intermediary element between the driving shoe and the surrounding water environment. It elastically connects to the driving shoe to transmit necessary forces while simultaneously acting as a barrier that reduces noise propagation into the water, thus mediating between the driving mechanism and the environmental constraint.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If impact hammers are used to drive piles, then installation speed is maintained, but radial expansion waves propagate through the pile causing high sound levels

Engineering Contradiction:

Improvesound transmissionVSAvoidpile driving capability

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The harmful radial expansion waves are extracted from the outer tube by using a separate inner member that is directly impacted by the hammer. The inner member absorbs the impact energy and transmits it to the pile, while the outer tube is elastically connected to minimize wave propagation, effectively separating the driving function from the noise-generating function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The elastic connection between the outer tube and driving shoe changes the mechanical parameters of the system, allowing the outer tube to move independently with reduced vibration transmission. This parameter change enables the outer tube to act as a vibration isolator while maintaining the necessary driving capability through the inner member.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If sound abatement structures like bubble curtains are installed, then some noise reduction is achieved, but high sound levels persist and operations are severely delayed

Engineering Contradiction:

Improvenoise mitigationVSAvoidconstruction timeline

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The noise attenuation structure (outer tube) is installed on the pile before driving begins. This preliminary action ensures that the noise barrier is already in place when driving starts, eliminating the need for separate noise mitigation operations and avoiding the time delays associated with installing bubble curtains or other external sound abatement structures during the driving process.

Inventive Principle:

Principle #10Preliminary action

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 effectively mitigates underwater noise by isolating the outer tube from radial expansion waves, reducing sound transmission into the environment, and allowing for the use of non-steel structural materials for the outer tube.

Implementation Method 1

an outer tube that is elastically connected to a driving shoe

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

substantially isolating the outer tube from high frequency vibrations of the shoe

Methodology Applied

Scientific EffectVibration isolation: Damping

Implementation Method 3

an annular channel filled with compressible material, allowing the outer tube to be pulled into the sediment without direct impact, thereby reducing sound propagation

Methodology Applied

Scientific EffectAcoustic absorption: Acoustic Absorption

Data Source

PatentUS9816246B2Pile with sound abatement for vibratory installations

Publication Date: 2017.11.14 UNIVERSITY OF WASHINGTON THROUGH ITS CENTER FOR COMMERCIALIZATION

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 the ground with either an impact driver or a vibratory driver that engages only the inner member. The inner member is rigidly connected to the driving shoe, and the outer tube is elastically connected to the driving shoe, such that vibrations from the outer tube is substantially isolated from vibrations in the driving shoe.