NEESR: Enhancement of Seismic Performance and Design of Partially-Grouted Reinforced Masonry Buildings
Reinforced masonry constitutes about 10% of all low-rise buildings in the US. Many of them are commercial, industrial, and school buildings. While most of the reinforced masonry structures constructed in the West Coast are fully grouted, almost all reinforced masonry construction in the rest of the country, including regions of high seismic risk, has partial grouting to make it economically competitive. However, the seismic performance of partially grouted reinforced masonry wall systems has not been sufficiently studied and is not well understood due to the complexity of their behavior, which can be attributed to the heterogeneity and anisotropy introduced by masonry blocks, block cavities, mortar joints, and grouted cells. This project is to enhance the understanding of the behavior of partially grouted masonry structures at the system as well as component level, and develop and validate economically competitive, improved, design details and retrofit methods to enhance their seismic performance...Learn More
NEESR: Inertial Force-Limiting Floor Anchorage Systems for Seismic Resistant Building Structures
The objective of this research project is to advance knowledge toward the development of innovative floor anchorage systems that reduce inertial forces during earthquakes and maintain a centered floor afterward. This new knowledge will be generated through a combination of analytical and experimental research, including nonlinear transient dynamic analysis, and using the equipment and tools available at two George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) facilities: the large scale structural and hybrid testing laboratory at Lehigh University and shake table testing at the University of California, San Diego (UCSD)...Learn More
NEES-Soft: Seismic Risk Reduction for Soft-Story Woodframe Buildings
The NEES-Soft Project, whose full title is "Seismic Risk Reduction for Soft-Story Woodframe Buildings" is a five-university multi-industry collaboration has the objectives of developing and demonstrating a methodology to retrofit soft-story woodframe buildings to (1) protect life safety and property by avoiding soft story collapse and excessive upper story accelerations, and (2) provide a mechanism by which soft story woodframe buildings can be retrofitted using performance-based seismic design (PBSD) to achieve a level of performance commensurate with their stakeholders target. This will be accomplished through a comprehensive combination of new numerical modeling procedures, hybrid testing for validation of two levels of soft story woodframe retrofit ...Learn More
Analytical and Experimental Development of Bridges with Foundations Allowed to Uplift During Earthquakes
Conventionally designed bridges rely on the concept of ductility, whereby the column reinforcement is detailed to ensure the development of flexural plastic hinges at the base and the top of the columns. While bridges designed in this manner may be safe from collapse, they are susceptible to considerable damage and permanent lateral displacements that can impair traffic flow and necessitate costly, time consuming, dangerous, and disruptive inspections and repairs. As an alternative design, bridges with columns supported on rocking foundations may develop large nonlinear deformations when subjected to strong shaking ...Learn More
Earthquake Performance of Large-Scale MSE Retaining Walls
The use of Mechanically Stabilized Earth (MSE) walls in civil engineering construction has become an increasingly popular alternative to conventional gravity and semi-gravity retaining walls over the last several decades. The low cost and ease of construction of MSE walls, combined with their excellent performance record, are well-suited for many applications. Extensive research has been conducted to characterize the behavior of MSE walls under seismic loading; however, these tests have necessarily used reduced-scale models due to the limited weight capacity of small shaking tables and geotechnical centrifuges...Learn More
Retaining Wall Shake Table Test and Design Using Tire Derived Aggregates as Backfill
In the United States, about 200-300 million tires are scrapped annually. Many of them had been stockpiled in landfills, which caused serious public health problems as well as environmental issues. These days, most developed countries prohibit legal and illegal stockpiling of scrap tires and promote recycling and recovering materials. Tire Derived Aggregate (TDA) is an engineered product made by cutting scrap tires into 5 to 450mm pieces to be used in civil engineering applications as lightweight aggregates. Unfortunately, seismic issues related with TDA backfill have not been addressed thoroughly since the development of TDA in the 1990's. The distinct mechanical properties of TDA from conventional backfill materials, particularly lightweight and compressibility, must be factors that influence seismic behavior of retaining walls.
The present research aims at establishing a reliable foundation for seismic design and assessment of TDA backfilled retaining walls through numerical and experimental investigations...Learn More
Shake-Table Tests of a Two-Story Reinforced Masonry Shear Wall System
A full-scale, two-story, fully-grouted, reinforced masonry shear wall system will be tested on the NEES outdoor shake table at the Englekirk S-tructural Engineering Center of UCSD. This will be the second and also the last structure to be tested on the shake table in a research project sponsored by NIST under an ARRA Measurement Science and Engineering Grant. The project is to study the seismic performance of fully-grouted reinforced masonry shear-wall structures, and to develop improved design methodologies, detailing requirements, and analytical methods for the design and performance assessment of these structures...Learn More
Full-Scale Structural and Nonstructural Building System Performance during Earthquakes & Post-Earthquake Fire
To date, only a handful of full-scale building experiments have been conducted. Of these, none have evaluated the post-earthquake fire performance of the complete building system and only select (in Japan) have they emphasized evaluating nonstructural component and system (NCS) response during earthquake shaking. This belies the fact that NCSs encompass more than 80% of the total investment in building construction and over the past three decades, the majority of earthquake-induced direct losses in buildings are directly attributed to NCS damage.
This landmark project involves earthquake and post-earthquake fire testing of a five-story building built at full-scale and completely furnished with NCSs, including...Learn More
Performance-Based Seismic Design Methods and Tools for Reinforced Masonry Shear-Wall Structures
Current code provisions and strength design methods for reinforced masonry shear-wall structures do not adequately distinguish the unique design requirements and performance characteristics of high-rise and low-rise masonry shear wall systems of different configurations. Moreover, current seismic design provisions for masonry structures are force-based with overlays of prescriptive requirements, some of which are neither practical nor rational and have not been substantiated with experiment research. This research...Learn More Test Schedule
Large-Scale Validation of Seismic Performance of Bridge Columns
The seismic behavior of full-scale bridge columns designed based on current Caltrans practice is being investigated using the UCSD shake table as part of an extensive test program with E-Defense (Japan) and UC Berkeley in an effort to improve current bridge design and analysis practices.Learn More Test Schedule
Collapse Vulnerability and Seismic Design of Metal Building Systems
Through support of the Metal Building Manufacturers Association, the Network for Earthquake Engineering Simulation, and the American Iron and Steel Institute, three Metal Building System specimens will be tested to determine the seismic response of various configurations.Learn More Test Schedule
NEESR-II A Seismic Study of Wind Turbines for Renewable Energy (WTRU)
The amount of electricity produced from the wind has steadily grown since its introduction in the 1980s and with the introduction of AB 32 is poised to grow substantially in California. Through support from the United States National Science Foundation (NSF) and specifically via the Network for Earthquake Engineering Simulation (NEES) and Oak Creek Energy Systems (OCES), a Gigawatt Wind Energy pioneer, a multiyear investigation into the seismic behavior of wind turbines is underway at the University of California, San Diego (UCSD).
This original research started with a forced and ambient vibration monitoring program at Oak Creek Energy Systems (OCES) with the assistance...Learn More
Seismic Design Guidelines of Retaining Walls with/without Sound Wall
The objective of the research project on retaining walls is to develop improved and validated rational guidelines for seismic design of retaining walls to overcome the drawbacks in the existing Caltrans design specification and tools. The research work involves 2 separate validation tests on two full-size retaining walls (each wall is about 8.5 feet long and 6 feet high Type 1 Semi-Gravity Reinforced Concrete Cantilever Wall, with a total height of 7.5 feet including a 1.5 feet thick bottom footing).
The first test includes one retaining wall without sound wall and the second test includes a sound wall on top of the second retaining wall. The walls will be backfilled...Learn More
Seismic Performance Assessment and Retrofit of Non-Ductile RC Frames with Infill Walls
Researchers of UC San Diego conducted shake table tests on a 3-story, non-ductile, masonry-infilled, reinforced concrete frame representing structures built in California in the 1920's. The tests on the 2/3 scale specimen are part of the collaborative project between University of Colorado at Boulder, Stanford University and University of California San Diego, which is the lead institution. The research project is funded by the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) and is already in its 4th and final year.
The goal of the research team led by Benson Shing, a UCSD structural engineering professor, is to develop and implement analytical tools to assess the seismic vulnerability...Learn More
Seismic Design Methodology for Precast Building Diaphragms
A one-half scale three story precast concrete diaphragm will be tested on the shake table at UCSD to investigate the behavior of long-span precast concrete diaphragms under seismic excitation. The project is funded by NSF GOALI and is being conducted by a multi-university and industry consortium.
This is a landmark test funded by NSF GOALI, the Precast/Prestressed Concrete Institute and the Charles Pankow Foundation. This project will assess the behavior...Learn More
Performance-Based Design of Masonry and Masonry Veneer
Researchers at UT Austin, Washington State University, North Carolina A&T State University, and the University of California at San Diego conducted a coordinated experimental and analytical study, intended to investigate the seismic performance of wood-stud construction with clay masonry veneer, and of reinforced concrete masonry construction with clay masonry veneer, designed according to current building codes.
Wood-stud wall segments with clay masonry veneer were tested quasi-statically out-of-plane and in-plane; identical segments were tested...Learn More
Seismic Response of a 7-Story RC Building
The objective of this research program was to verify the seismic response of reinforced concrete wall systems designed for lateral forces obtained from a displacement-based design methodology. A 7-story full-scale slice of a reinforced concrete residential building with cantilever structural walls was tested on the UCSD shake table. The project was funded by the Englekirk Board of Advisors, an industry group supporting research at the Charles Lee Powell Structural Laboratories at the University of California, San Diego.