Core Recovery Sleeve Adapter for Undisturbed Soil Sampling
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Solution Overview
Problem
Existing drilling systems fail to efficiently retrieve nearly undisturbed soil samples from loose ground due to mechanical and thermal stresses, leading to rapid wear and contamination, with no device offering a satisfactory service life or core quality.
Innovation Solution
A drilling system comprising a drill head, drill pipe, initial pipe, drill bit, pressure, flushing and recovery pipe, and a sleeve adapter that mediates between the rotating pipe and non-rotating sleeve, absorbing high impact forces and preventing rotation, while using flushing water for cooling and lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drilling systems are used in loose ground, then drilling operations can be performed, but mechanical and thermal stresses cause rapid wear and contamination, leading to short service life and poor core quality
Solution Approach 1:
The drilling system is divided into functionally independent segments: the drill head assembly that rotates and applies cutting force, the initial tube that advances through the ground, and the sleeve that remains stationary to capture the core. This segmentation allows each component to be optimized for its specific function, with the sleeve being protected from mechanical and thermal stresses by not being part of the rotating assembly.
Solution Approach 2:
The initial tube acts as an intermediary between the rotating drill head and the stationary sleeve. It transmits the drilling forces from the drill head to advance the sleeve through the ground without requiring the sleeve itself to rotate, thereby protecting the sleeve from mechanical and thermal stresses that would otherwise cause rapid wear.
2Productivity
If conventional drilling systems are used, then drilling operations can proceed, but frequent interruptions occur due to wear and contamination, reducing productivity
Solution Approach 1:
By separating the rotating drill head from the stationary sleeve, the system eliminates wear between these components. The sleeve captures cores continuously without interruption because it is not subjected to rotational mechanical stresses or thermal loading, allowing faster drilling operations with fewer stops for maintenance.
Solution Approach 2:
The drill head and initial tube are designed as consumable components that can be easily replaced when worn, while the expensive sleeve is protected and reused many times. This approach is economically efficient because the low-cost rotating parts absorb the wear, allowing the high-value sleeve to maintain productivity over extended periods without interruption.
3Manufacturing precision
If the sleeve rotates during drilling, then it can be advanced through the ground, but this causes contamination and disturbs the core sample quality
Solution Approach 1:
The initial tube serves as a mediator that advances the stationary sleeve through the ground. The drill head rotates the initial tube, which then pushes the non-rotating sleeve forward. This intermediary mechanism allows the sleeve to be advanced through the ground without rotating, preserving core sample quality by preventing contamination from rotational movement.
Solution Approach 2:
The rotational function is extracted from the sleeve and assigned to the drill head and initial tube. The sleeve retains only its core function of capturing and holding the soil sample, while the advancement function is achieved through the rotating initial tube pushing it forward, eliminating the harmful combination of rotation and core contact.
4Manufacturing precision
If liners are used in the sleeve, then volatile contaminants are trapped and core quality is improved, but device complexity and cost increase
Solution Approach 1:
The stationary sleeve acts as an intermediary containment vessel that protects the core sample from contamination during retrieval. Because the sleeve does not rotate, it provides a stable, non-contaminating environment for the core, and when combined with a liner, creates an effective barrier against volatile contaminants without requiring complex active sealing mechanisms.
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 enables faster, more reliable retrieval of undisturbed soil samples with reduced interruptions, extended service life, and minimal contamination, allowing for continuous drilling operations.
Implementation Method 1
using flushing water for cooling and lubrication
Implementation Method 2
using flushing water for cooling and lubrication
Implementation Method 3
sleeve adapter that mediates between the rotating pipe and non-rotating sleeve, absorbing high impact forces
Data Source
AI summary
The device is operated with a conventional rotary drive with pile hammer. The torque and the ramming impacts of the drill head are transmitted to a drilling initial tube with drill bit. A sleeve without rotation stands inside the rotating initial tube. It rests at the bottom on the inside of the drill bit rotating below it. As a special feature, the sleeve is connected to the rotating drill head by means of a sleeve adapter with axially consecutive parts that can be rotated against each other and a PFR pressure, flushing and recovery tube connected to it. The PFR rotates with the drill head and the drill pipe, and the sleeve adapter communicates with the non-rotating sleeve. The PFR is used firstly to apply compressive force to the sleeve from above, secondly to flush it by guiding the flushing water for drilling in the PFR and forcing it out of the sleeve, and thirdly to allow the sleeve to be recovered for an almost undisturbed drilling test.