Guardrail Anchor Post Shear Mechanism
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Solution Overview
Problem
Existing guardrail systems can create a ramp effect when deformed by vehicle impact, allowing vehicles to slide over the restraint system due to the bending of posts, which is not effectively addressed by conventional designs.
Innovation Solution
A guardrail arrangement featuring two-part posts with an anchor post embedded in the subsurface and a holding post coupled via shearable screws, designed to shear off when a predetermined force is exceeded, preventing post bending and ramp formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid posts are used to support guardrails, then the guardrail system can effectively restrain vehicles, but the posts may deform or bend under impact creating a ramp effect that allows vehicles to slide over the system
Solution Approach 1:
The post is divided into two separate components: an anchor post embedded in the substrate and a support post that holds the guardrail. This segmentation allows the support post to be designed for optimal guardrail support while the anchor post provides stable ground anchoring, preventing the bending and ramp effect that occurs in monolithic posts.
Solution Approach 2:
The anchor post is pre-installed and embedded in the substrate before the support post is attached. This preliminary action ensures that the anchoring structure is already in place and properly positioned, allowing the support post to be securely mounted without requiring post-installation adjustments that could compromise structural integrity.
2Ease of manufacture
If posts are driven into the ground as one-piece structures, then installation is simplified, but the posts can bend and form ramps under vehicle impact
Solution Approach 1:
The post system is segmented into an anchor post and support post, allowing each component to be optimized for its specific function. The anchor post is designed for stable ground embedding while the support post is designed for guardrail mounting, preventing the structural failures that occur in one-piece designs.
Solution Approach 2:
The problematic element (the vulnerable portion of the post that bends under impact) is extracted and separated from the anchoring element. By removing the connection between the guardrail-supporting portion and the ground-anchoring portion, the design eliminates the ramp effect while maintaining installation simplicity through modular assembly.
3Object-affected harmful factors
If posts are bolted to foundations or road surface, then the ramp effect is reduced, but the system becomes more complex and requires additional foundation work
Solution Approach 1:
The post system is divided into an anchor post that is driven into the ground (simple installation) and a support post that attaches to it (reduces ramp effect). This segmentation achieves the ramp effect reduction of bolted systems while maintaining the installation simplicity of driven posts, as the anchor post is driven in and the support post is then attached without requiring complex foundation work.
Solution Approach 2:
The anchor post serves as an intermediary element between the ground substrate and the support post. It provides a stable embedded anchor point that eliminates the need for complex foundations while preventing the ramp effect, as the support post is securely attached to this intermediate anchor structure rather than directly to the ground or requiring separate foundation work.
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 effectively absorbs impact energy by shearing the screws, reducing the risk of vehicle stray and maintaining the vehicle within the guardrail system without post deformation, thus preventing ramp formation and enhancing safety.
Implementation Method 1
The screw bolts (15) are designed to shear off when a predetermined shear force is exceeded
Implementation Method 2
The anchor post (9) is embedded in the substrate (7) with a large part of its length (10). It preferably projects with a height (11) above the surface (6) of the substrate (7)
Data Source
Figure 1~2
Figure 3
Figure 4a~4f
AI summary
The present invention relates to a guardrail arrangement 1, in particular used as a vehicle restraint system on a roadway, wherein at least one guardrail strand 2 is arranged in series from guardrails at a vertical distance to a surface 6 of a substrate 7 and is attached to posts 5, which is characterized in that the posts 5 are formed in the vertical direction V in two parts from an anchor post 9 embedded in the substrate 7 and a retaining post 8 coupled thereto.