Link to Latest Report: Coming Soon
Background:
This research proposal introduces a new column-bent cap connection, with innovative materials such as Ultra-High Performance Concrete (UHPC), Shape Memory Alloy (SMA) and Engineered Cementitious Composite (ECC) to promote the self-centering behavior and postearthquake functionality of bridges subjected to earthquake ground motions.
Circular columnswill be considered in this study. The significance of this research is to propose a simple yet practical and effective use of innovative materials such as UHPC, SMA and ECC as substructure connection for bridges in medium and high seismic regions. Several factors are simplified in the construction of the column due to novel properties of UHPC and SMA to minimize the splice length between column longitudinal reinforcement.
This phase of study will focus on comprehending on fundamental behavior of the proposed system and identify, possible future steps that are needed for implementation of the idea in the field. Research builds on previous work conducted at FIU(Azizinamini, et al) in the form of moving the plastic hinge outside of capacity protected areas in seismic design process, through use of UHPC. The research will involve experimental studies, in the form of 2/3 scaled column specimens subjected to constant axial load and cyclic lateral loads, small scale component tests to comprehend the behavior of SMA and durability aspects of the proposed system. The research is expected to develop a roadmap to implement the proposed idea in the field as well as tentative seismic design methodology that can be applied to bridge columncap beam connections, column-footing connections, and plastic hinge zones.
Objective:
The objective of this research is to demonstrate:
- Low-damage bridge columns with improved seismic performance compared to
conventional cast-in-place columns. - Reduced and controlled concrete damage using UHPC in plastic hinge regions.
- Reduced residual displacement by incorporating SMA with self-centering capability.
- Development of a step-by-step seismic design method for bridge column-cap beam
connections, and plastic hinge zones with UHPC, SMA, and ECC.
Scope:
The proposed project includes several tasks
- Task 1- Literature Review
- This task involves conducting a comprehensive review of existing literature on the
seismic applications of SMA, UHPC and ECC, focusing on design guidelines and the
latest design guidance available for the structural design of SMA, UHPC and ECC,. The
review will cover case studies, current practices, and standards to establish a solid
foundation for the project.
- This task involves conducting a comprehensive review of existing literature on the
- Task 2: Developing Connection Detail
- Findings from Task 1 and previous experiences by PI and Co-PIs, and preliminary
nonlinear finite element analysis, details of proposed connection will be finalized. It is
intended to have State DOTs with interest in seismic evaluation to be involved in the
project and obtain their input as project progress. This should help during field
implementation phase of the project.
- Findings from Task 1 and previous experiences by PI and Co-PIs, and preliminary
- Task 3: Material Test
- In this task, material tests for UHPC, ECC, and SMA will be conducted to assess the
material characteristics for seismic performance of the proposed bridge column.
- In this task, material tests for UHPC, ECC, and SMA will be conducted to assess the
- Task 4: Experimental Study
- Task 5: Analytical Studies
- Before initiating experimental work, preliminary non-linear finite element analysis will
be carried out to study the proposed connection detail and develop preliminary
understanding of the system. These preliminary models will be calibrated against
research data that is available to research team from previous studies. Following the
completion of the first column test, the developed numerical model will be calibrated and
it will then be used to conduct parametric studies for development of design
methodologies.
- Before initiating experimental work, preliminary non-linear finite element analysis will
- Task 6: Final Report
- The final task involves a full assessment of the findings, data, and analyses from the
previous tasks into a comprehensive final report. This report will include detailed
guidelines and recommendations for designing and implementing UHPC and CFRP
tendons in bridge columns, particularly focusing on their application in seismic regions.
- The final task involves a full assessment of the findings, data, and analyses from the
Research Team:
Principal Investigator: Bijan Khaleghi, Ph.D., P.E.
Co-Principal Investigator: Ankitha Arvan, Ph.D. and Atorod Azizinamini, Ph.D.,
P.E.