Mechanical Anchorage Device for Tie Rods in Unconsolidated Ground
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Solution Overview
Problem
Conventional anchorage tie rods face issues with mortar-ground adhesion losses, leading to compromised resistance and stability, especially in unconsolidated or water-bearing grounds, requiring complex calculations and uncertain load tests.
Innovation Solution
An anchorage device with penetrating and anchorage plates that are driven into the hole walls and embedded with slurry, providing mechanical resistance instead of relying on friction, significantly reducing active length and eliminating extraction issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional anchorage tie rods use mortar-ground adhesion for anchoring, then the anchoring resistance can be achieved, but adhesion losses occur during useful life compromising resistance and stability
Solution Approach 1:
The patent replaces the chemical adhesion mechanism (mortar-ground adhesion) with a mechanical anchoring system. The anchorage device comprises a body with anchoring elements that mechanically engage with the ground through physical interlocking and friction, eliminating dependence on mortar adhesion that degrades over time. This mechanical system provides stable, long-lasting anchoring resistance without the adhesion losses inherent in conventional mortar-based systems.
Solution Approach 2:
The patent introduces an intermediary anchorage device between the tie rod and the ground. This device includes a body with anchoring elements that serve as a mediator, transferring loads from the tie rod to the ground through mechanical engagement rather than direct mortar adhesion. The intermediary structure ensures stable load transfer while protecting against adhesion degradation.
2Reliability
If the active length is increased to improve hold in unconsolidated grounds, then the anchoring resistance increases, but the complexity of installation and uncertainty of performance increases
Solution Approach 1:
The patent employs a dynamic installation process where the anchorage device is inserted into the perforating hole and then expanded in place. The body can be pushed along the tie rod to the desired depth, and then anchoring elements are deployed radially outward to engage with the ground. This dynamic insertion and expansion mechanism provides reliable anchoring hold while simplifying installation compared to traditional methods requiring precise pre-positioning of long active lengths.
Solution Approach 2:
The anchorage device is segmented into distinct functional components: a body for insertion, anchoring elements for ground engagement, and a expansion mechanism. This segmentation allows the device to be installed in modular sections and then activated to provide full anchoring capacity, reducing installation complexity while maintaining reliable hold even in challenging ground conditions.
3Adaptability or versatility
If conventional tie rods are used in water-bearing grounds, then installation is possible, but adhesion losses occur compromising resistance
Solution Approach 1:
The patent replaces mortar-based adhesion with a mechanical anchoring system that is inherently resistant to water degradation. The anchoring elements physically engage with the ground through friction and interlocking, a mechanism that does not depend on chemical adhesion that water can compromise. This mechanical system maintains reliable anchoring resistance in water-bearing grounds where conventional mortar adhesion fails.
Solution Approach 2:
The patent changes the fundamental anchoring mechanism from chemical adhesion (mortar-ground bond) to mechanical engagement (friction and interlocking). This parameter change in the anchoring principle makes the system insensitive to water presence, as mechanical friction and physical interlocking remain effective in wet conditions where chemical adhesion would degrade.
4Quantity of substance
If the active length is reduced to minimize material use, then cost-effectiveness improves, but anchoring resistance may be compromised
Solution Approach 1:
The patent uses a dynamic expansion mechanism that allows the anchorage device to be inserted at a compact size and then expanded to its full anchoring capacity in place. This enables the use of shorter active lengths while maintaining full anchoring resistance, as the expansion process creates adequate ground engagement without requiring proportionally longer material lengths.
Solution Approach 2:
The anchorage device is designed with segmented anchoring elements that can be deployed radially from a compact body. This segmentation allows the anchoring function to be achieved with minimal material consumption, as the distributed anchoring elements create effective ground engagement without requiring long continuous active length, improving cost-effectiveness while maintaining reliability.
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 device ensures stable anchoring with mechanical resistance, reducing active length, eliminating extraction problems, and allowing application in various ground types with improved safety and cost-effectiveness.
Implementation Method 1
a hydraulic cylinder comprising a cylinder body (20; 20A) and a cylinder rod (30; 30A) slidably mounted to the cylinder body (20; 20A), the cylinder body (20; 20A) comprises a cylinder chamber (201; 201A) suitable for receiving a pressurized hydraulic fluid (F)
Implementation Method 2
a cementitious composition suitable for embedding said at least one penetrating and anchorage plate (40) in the side wall (SW) of the perforating hole (H)
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
There is described an anchorage device (1; 1A; 1E) for anchorage tie rods suitable for being inserted into a perforating hole (H) made in a ground to allow anchoring an anchorage tie rod (5). The features of the anchorage device meet the need to increase the efficiency of transferring loads to the ground while almost completely eliminating the extraction problems of the tie rod. Indeed, the anchoring no longer occurs by relying on the friction resistance due to the mortar-ground adhesion, rather it is ensured by the mechanical resistance of penetrating and anchorage plates (40) which are first driven into the side wall (SW) of the perforating hole and then embedded with slurry. Therefore, with such a device, it will be more than sufficient to penetrate about 3 to 4 meters into the active stretch (thus drastically reducing the active length which generally may also reach 40 meters for conventional tie rods), open the penetrating and anchorage plates (40) by means of actuating a hydraulic cylinder, and once the penetration is complete, inject cement grout. Once anchored, the system can no longer be removed because the penetrating and anchorage plates (40), which are now spread and penetrated in the side wall (SW) of the hole (H), have an open diameter which is much greater than the diameter of the perforation, thus achieving, as mentioned, a mechanical type anchoring and no longer a friction anchoring. A process for anchoring anchorage tie rods is also described.