Construction Frame Shear Lug Anchor Rod Installation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional shear lugs weaken the foundation and are prone to weld failure under high shear loads, especially when close to the edge of the foundation, as they are fitted into preformed keys and welded to base plates.
Innovation Solution
A shear lug affixed to anchor rods and installed within the foundation during concrete pouring, subsequently attached to structural elements, distributing shear forces effectively through anchor rods and reducing the risk of foundation fracture and weld failure by being a unitary angled piece of steel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a conventional shear lug is fitted into a preformed key in the foundation and welded to the base plate, then shear force transfer is achieved, but the foundation is weakened and becomes prone to fracture
Solution Approach 1:
The shear lug is pre-installed into the foundation during concrete pouring, before the foundation is complete. This preliminary action allows the lug to be embedded in fresh concrete, creating a strong bond without requiring a preformed key that would weaken the foundation. The anchor rods are also installed beforehand to receive the shear lug.
Solution Approach 2:
The invention merges the shear lug installation with the foundation pouring process itself. Instead of creating a separate preformed key and then fitting the lug, the lug is installed as part of the foundation construction process, combining multiple operations into one unified action that strengthens rather than weakens the foundation.
2Force
If a shear lug is welded to the base plate to transfer shear forces, then shear transfer is achieved, but the weld is subject to high stresses and can fail under high shear loads
Solution Approach 1:
The invention extracts the welding operation from the shear force transfer path. Instead of welding the shear lug to the base plate, the design uses separate anchor rods that mechanically connect to both the shear lug and the base plate, removing the weld from the critical stress path and eliminating weld failure risk.
Solution Approach 2:
The anchor rods serve as an intermediary element between the shear lug and the base plate. Rather than directly welding the shear lug to the base plate, the anchor rods mediate the connection, providing a reliable mechanical fastening that avoids the weaknesses of welding under high shear stress.
3Ease of operation
If a shear lug is installed after foundation formation, then installation flexibility is maintained, but the shear lug cannot effectively distribute shear loads to the foundation
Solution Approach 1:
The shear lug and anchor rods are installed as preliminary elements during foundation construction, before the foundation is complete. This timing allows the shear lug to be properly embedded and bonded to the foundation, ensuring effective shear load distribution while still maintaining installation flexibility through the pre-installation approach.
Data Source
AI summary
A shear lug is disclosed for transferring shear stresses from a structural element, such as a column in a framing element, down into the foundation supporting the framing element. The shear lug is not initially affixed to the structural element. The shear lug is instead affixed to anchor rods of an anchorage assembly, and is installed into the foundation with the anchorage assembly at the time the concrete foundation is poured. The structural element is subsequently affixed to the anchor rods, so that shear forces are transferred from the structural element, through the anchor rods and to the shear lugs, which effectively dissipate the shear forces to the foundation.