Past Projects

  • Modular Testbed Building: A Shared-Use Reusable Equipment Resource

    Modular Testbed Building: A Shared-Use Reusable Equipment Resource

    The Modular Testbed Building, or MTB2, will be the first specimen tested on the newly upgraded 6 degrees of freedom Large High Performance Outdoor Shake Table (LHPOST6). The MTB2 is designed to be reconfigurable and reusable community shared-use equipment resource. Reuse is accomplished by having a connection scheme that allows yielded members to be replaced, while leaving the rest of the structure in place. This modular design enables low-cost testing of components and subsystems at large to full-scale under simulated dynamic 3D loading.

  • Seismic Collector Project Elevation

    Seismic Performance of Collectors in Steel Building Structures

    Collectors are key structural elements in the Seismic Force-Resisting System (SFRS), delivering the inertial forces that develop in the floor system to the primary (vertical plane) lateral force-resisting elements. In contrast to the vertical-plane SFRS elements (shear walls, braced frames, moment frames, etc.), no research efforts or experimental program to date has focused specifically on collectors. Instead, design procedures for collectors have traditionally applied special seismic load combinations in ASCE-7 involving the application of the System Overstrength Factor.

  • Collaborative Research: Seismic Resiliency of Repetitively Framed Mid-Rise Cold-Formed Steel Buildings

    Collaborative Research: Seismic Resiliency of Repetitively Framed Mid-Rise Cold-Formed Steel Buildings

    The need for low cost, multi-hazard resilient buildings constructed of sustainable, low-carbon footprint materials is urgent. Mid-rise buildings framed from thin-walled, cold-formed steel (CFS) have the ability to support this urgent need. The potential benefits of CFS-framed structures include low installation and maintenance costs, high durability and ductility, lightweight framing, and use of a non-combustible material.

  • Collapse Simulation of Shear-Dominated Reinforced Masonry Wall Systems

    Collapse Simulation of Shear-Dominated Reinforced Masonry Wall Systems

    Seismic design codes have to ensure that buildings have a low probability of collapse in the event of a severe earthquake. To develop such standards, the ability to assess the collapse margin ratios of building systems designed according to given specifications is of critical importance. Under severe seismic forces, reinforced masonry (RM) wall structures may develop complicated nonlinear behavior involving interaction between steel and masonry.

  • Development and Validation of a Resilience-based Seismic Design Methodology for Tall Wood Buildings: Phase I Test

    Development and Validation of a Resilience-based Seismic Design Methodology for Tall Wood Buildings: Phase I Test

    With global urbanization trends, the demands for tall residential and mixed-use buildings in the range of 8~20 stories are increasing. One new structural system in this height range are tall wood buildings which have been built in select locations around the world using a relatively new heavy timber structural material known as cross laminated timber (CLT). However, the majority of existing tall CLT buildings are located in non-seismic or low-seismic regions of the world.

  • Earthquake and Post-Earthquake Fire Performance of Mid-Rise Light-Gauge Cold-Formed Steel Framed Buildings

    Earthquake and Post-Earthquake Fire Performance of Mid-Rise Light-Gauge Cold-Formed Steel Framed Buildings

    Light-gauge cold-formed steel (CFS) framed multi-story residential housing has the potential to support societies urgent need for low cost, multi-hazard resilient housing. CFS-framed structures offer lower installation and maintenance costs, are durable, ductile, lightweight, and manufactured from recycled materials. In addition, consistency in material behavior and low material costs are added benefits compared with their wood-framing counterparts. The components of CFS-framed assemblies (studs, track, joists) can be assembled quickly and with relative ease into prefabricated panels.

  • Spillway Retaining Wall Shake Tablae Test Program

    Spillway Retaining Wall Shake Tablae Test Program

    This research aims ultimately to provide seismic performance of a spillway based on experimentally validated engineering procedures with variation of topographical ground conditions. The research work involves intensive dynamic tests for the steel spillway specimen (3.3 ft height, 6 ft width, and 9 ft long in model scale). This spillway is buried in the laminar soil shear container. Dimensions of the container are a length of 22 ft, a width of 9.6 ft, and a height of 11 ft.

  • Helical Piles Guidelines

    RAPID: Large-Scale Shake Table Test to Quantify Seismic Response of Helical Piles in Dry Sands

    Helical piles are deep foundation elements that look like, and are installed like, a large steel soil screw – they have a slender steel shaft with any number of round plates at the tip to provide support to the structure they hold. Helical piles are spun into the ground with a large torque motor and provide support through soil bearing on the plates and along the shaft.

  • Seismic Design Guidelines of Cut-and-Cover Tunnel

    Seismic Design Guidelines of Cut-and-Cover Tunnel

    The objective of the research project is to develop improved and validated rational guidelines for seismic design of cut-and-cover tunnels to overcome the drawbacks in the existing Caltrans design specification and tools. The research work involves intensive dynamic tests for the 1/9 scale steel tunnel specimen (4 ft height, 6 ft width, and 9 ft long in model scale), that is adopted from the Doyle Drive Battery Tunnel (reinforced concrete structure, San Francisco, CA).

  • Unibody House 3D Rendering

    Seismically Isolated Unibody Residential Buildings for Enhanced Life-Cycle Performance

    Although traditional framed residential structures provide a high level of life safety during an earthquake, their vulnerability to damage can be very costly. After the 1994 Northridge Earthquake, it was estimated that $20 billion were issued in insurance payouts for damaged residences. In addition, over 60,000 people were displaced from their homes for a significant period of time. In order to reduce the damage seen by these structures, the current design standards must be revised to prevent the ultimate load from being reached at large damaging drifts. 

  • NEESR: Enhancement of Seismic Performance and Design of Partially-Grouted Reinforced Masonry Buildings

    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.

  • NEESR: Inertial Force-Limiting Floor Anchorage Systems for Seismic Resistant Building Structures

    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.

  • Analytical and Experimental Development of Bridges with Foundations Allowed to Uplift During Earthquakes

    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.

  • Earthquake Performance of Large-Scale MSE Retaining Walls

    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.

  • Retaining Wall Shake Table Test and Design Using Tire Derived Aggregates as Backfill

    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.

  • Shake-Table Tests of a Two-Story Reinforced Masonry Shear Wall System

    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 Structural 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.

  • Full-Scale Structural and Nonstructural Building System Performance during Earthquakes & Post-Earthquake Fire

    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.

  • Performance-Based Seismic Design Methods and Tools for Reinforced Masonry Shear-Wall Structures

    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.

  • Collapse Vulnerability and Seismic Design of Metal Building Systems

    Collapse Vulnerability and Seismic Design of Metal Building Systems

    Metal Building Systems make up a large portion of new low-rise, non-residential construction today. These systems are designed to be extremely efficient and as such exhibit very different behavior than other steel building systems. The current building codes lump Metal Building Systems in with other types of steel building systems in terms of their design criteria.

  • Seismic Design Guidelines of Retaining Walls with/without Sound Wall (SDGRW)

    Seismic Design Guidelines of Retaining Walls with/without Sound Wall (SDGRW)

    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).

  • Seismic Performance Assessment and Retrofit of Non-Ductile RC Frames with Infill Walls

    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.

  • Performance-Based Design of Masonry and Masonry Veneer

    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.

  • Seismic Design Methodology for Precast Building Diaphragms

    Seismic Design Methodology for Precast Building Diaphragms

    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 of long-span precast concrete diaphragms to input earthquake excitation. This is a pre-NEES project being carried out by a multi-university consortium: University of Arizona, Lehigh University and the University of California at San Diego. Extensive testing on precast concrete floor connections is taking place at LU. Computational modeling is being performed at UA and UCSD.

  • Seismic Response of a 7-Story RC Building

    Seismic Response of a 7-Story RC Building

    Experience in earthquakes has shown that structural walls are an excellent lateral force resisting system but in high-seismic regions like California, buildings incorporating structural walls can be prohibitively expensive and difficult to build.