In-situ Observation System for Shallow-Water Seabed Boundary Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current in-situ observation systems for the bottom boundary layer (BBL) over shallow-water cohesive seabeds face challenges such as high costs, complex operations, instability, and limited observation accuracy due to seabed erosion and subsidence, especially when using high-pressure water-jet drilling, which struggles to penetrate deep and is affected by the seabed's porosity.
Innovation Solution
A modularized, low-cost, easy-to-operate in-situ observation system utilizing a hydraulic pile foundation system based on soil liquefaction principles, with a stainless-steel frame and porous discs to stabilize the observation platform, allowing for deeper penetration and reduced interference with water flows, enabling continuous and comprehensive observation of water and sediment motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If high-pressure water-jet drilling is used to penetrate the seabed, then the pile depth can be increased, but the cost and operational complexity increase significantly
Solution Approach 1:
The pile driving process is divided into two distinct phases: first, a borehole is prepared using high-pressure water-jet drilling; second, the pile is installed using vibration-driven penetration. This segmentation allows each phase to be optimized independently, using high-pressure water-jet only where needed for borehole creation, and vibration for the actual pile penetration, thereby reducing overall system complexity while achieving deep pile installation.
Solution Approach 2:
The patent replaces the traditional mechanical hammer-driven piling system with a vibration-driven system. The vibration device generates oscillatory forces that enable the pile to penetrate the seabed through soil liquefaction and reduction of friction, eliminating the need for complex mechanical hammers and associated driving rigs, thus significantly reducing device complexity while achieving deep penetration.
2Length of stationary object
If high-pressure water-jet drilling is used to penetrate the seabed, then the pile depth can be increased, but the operational cost increases
Solution Approach 1:
The pile driving process is divided into two distinct phases: first, a borehole is prepared using high-pressure water-jet drilling; second, the pile is installed using vibration-driven penetration. This segmentation allows each phase to be optimized independently, using high-pressure water-jet only where needed for borehole creation, and vibration for the actual pile penetration, thereby reducing overall system complexity while achieving deep pile installation.
Solution Approach 2:
The patent replaces the traditional mechanical hammer-driven piling system with a vibration-driven system. The vibration device generates oscillatory forces that enable the pile to penetrate the seabed through soil liquefaction and reduction of friction, eliminating the need for complex mechanical hammers and associated driving rigs, thus significantly reducing device complexity while achieving deep penetration.
3Stability of the object's composition
If the observation platform is fixed on the seabed using traditional methods, then the platform can be stabilized, but the platform subsides due to seabed erosion and scouring
Solution Approach 1:
Before installing the observation platform, the patent pre-drills boreholes to the required depth and installs piles with vibration-driven penetration. The piles are then secured to the platform base, creating a preliminary reinforcement structure that prevents subsequent subsidence. This preliminary anti-action counteracts the harmful effects of seabed erosion and scouring before they can cause platform settlement.
Solution Approach 2:
The patent performs preliminary actions by first creating boreholes and installing piles to the required depth before placing the observation platform. The vibration-driven pile installation ensures deep penetration and secure anchoring in advance, establishing a stable foundation that prevents future subsidence and maintains platform reliability throughout the observation period.
4Stability of the object's composition
If settlement plates are used to prevent subsidence, then the platform can be stabilized, but the plate size is limited by the observation space
Solution Approach 1:
Instead of using a single large settlement plate, the patent segments the stabilization function into multiple deep-penetrating piles distributed around the platform base. Each pile independently anchors to the seabed at significant depth, collectively providing the necessary stability without requiring a large surface area. This segmentation allows the observation space to remain maximized while achieving adequate stabilization.
Solution Approach 2:
The patent transitions from a two-dimensional solution (large settlement plates on the seabed surface) to a three-dimensional solution (deep-penetrating piles extending vertically into the seabed). By utilizing the vertical dimension for pile penetration depth rather than expanding the horizontal footprint, the system achieves stable platform fixation without compromising the observation space area.
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 system provides stable, cost-effective, and interference-free observations with adjustable instrument arrangements, achieving deeper pile penetration and improved observation accuracy, reducing operational complexity and economic costs while maintaining stability during extreme weather conditions.
Implementation Method 1
with scouring of a high-pressure water flow to the seabed, pore water in seabed soil is supersaturated and the soil is liquefied, thereby inserting each of the hollow pile pipes into the seabed
Implementation Method 2
a manual or mechanical auxiliary vibration on the pile pipe or the water-jet pipe can be applied to accelerate the penetration of pore water and liquefaction of soil in the consolidated layer
Data Source
AI summary
The present disclosure provides an in-situ observation system for a bottom boundary layer (BBL) over a shallow-water cohesive seabed and an arrangement method thereof. It establishes a low-cost and easy-operation hydraulic pile foundation system (2), which can ensure the piling depth to achieve the anti-settling and stability. The stainless-steel sticks are assembled freely to construct the interference-free observation unit (1). As the porous discs are used between the feet of the observation unit (1) and the top of the bottom piles, the observation system can be accurately fixed to the pile foundation. It is thus not limited by the self-weight and can integrate various instruments upon requirement. The components in this system can be easily obtained and conveniently maintained. The present disclosure has the advantages of low-cost and stability, can be widely used for long-term in-situ observation of the BBL.