Single-Sided Reinforced Masonry Wall Seismic Retrofit
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Solution Overview
Problem
Unreinforced masonry buildings are highly vulnerable to earthquake damage due to their low tensile strength and limited ductility, and existing reinforcement methods often require access to both sides of the wall, which is not feasible in all cases, potentially disrupting the facade or leaving traces.
Innovation Solution
The method involves creating elongated passageways in the masonry wall with slots open only on one side, allowing reinforcement members to be embedded in an adhesive substance without accessing the second side, and using a stabilizing layer with high elongation at break to accommodate deformations without cracking, ensuring the wall's integrity during earthquakes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If FRP strips are placed on both sides of the wall to provide flexural resistance, then the seismic resistance is improved, but the construction complexity and accessibility requirements worsen
Solution Approach 1:
The invention extracts the reinforcement function from the traditional two-sided FRP application and relocates it to embedded reinforcement elements (rebar, steel mesh, or steel profiles) placed within passageways and slots created in the masonry wall. This allows the wall to achieve flexural resistance from a single-sided construction approach, eliminating the need to access both sides of the wall while maintaining seismic performance.
Solution Approach 2:
The invention introduces mortar as an intermediary material that fills passageways and bonds reinforcement elements to the masonry units. This mortar mediator transfers forces between the reinforcement and the masonry, enabling effective seismic resistance without requiring access to both wall sides, thus resolving the contradiction between reliability and construction complexity.
2Reliability
If FRP is applied on the exterior side of the wall, then the flexural resistance is improved, but the facade appearance is disrupted
Solution Approach 1:
The invention extracts the visible FRP application from the exterior facade and replaces it with embedded reinforcement elements concealed within the masonry wall structure. The reinforcement is placed in passageways and slots that are filled with mortar, making the reinforcement invisible from the exterior while maintaining the necessary flexural resistance for seismic performance.
3Reliability
If reinforcement is applied to increase tensile strength, then the earthquake resistance is improved, but the wall mass increases
Solution Approach 1:
The invention applies reinforcement locally at critical locations within the masonry wall rather than uniformly throughout. By placing reinforcement elements in specific passageways and slots where tensile stresses are highest, the wall achieves improved earthquake resistance with minimal additional mass, avoiding the need to increase the overall wall thickness or mass.
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
This approach effectively reinforces masonry walls without altering the inaccessible side, enhancing their resistance to earthquakes by delaying complete collapse to higher load levels, thereby reducing the risk of casualties and damage.
Implementation Method 1
The reinforcement members in the passageways are each embedded in an adhesive substance, the adhesive substance being bonded to each of the reinforcement members and to an inner surface of the passageway in which the reinforcement member is provided.
Implementation Method 2
using a stabilizing layer with high elongation at break to accommodate deformations without cracking, ensuring the wall's integrity during earthquakes
Data Source
AI summary
A masonry wall is provided with a plurality of passageways. At least one reinforcement member is provided in each of the passageways. The reinforcement members include a first group of reinforcement members each having a centre line on the first side of a midplane of the wall and a second group of reinforcement members each having a centre line on the second side of the midplane. The passageways include slots that are open horizontally to the first side of the wall only. The second group of reinforcement members are arranged in passageways located spaced from the second wall surface opposite of the first wall surface. The reinforcement members in the passageways are each embedded in an adhesive substance bonded to the reinforcement members and to an inner surface of the passageway in which the reinforcement member is provided.