Taylor Devices Logo
RESOURCES

Seismic Applications
Case Study

67. U.S. Design of Structures with Damping Systems

This paper presents an earthquake design procedure and a case study of the Vacaville Police Headquarters. The design goal for this essential facility was to provide immediate occupancy after a 475-year return seismic event. The project also required construction cost within typical code conforming buildings. A combination of Special Moment Resisting Frames (SMRF) and Fluid Viscous Dampers (FVDs) was used as the lateral force resistance system. This system, as described by Gimmel, Lindorfer, and Miyamoto, (2002) results in cost efficiency and superior seismic performance. The 2000 NEHRP (FEMA, 2000) guideline was used to design the project, since it is considered to be a state-of-art procedure for seismic damping devices. This project was the first structure in the United States to use this advanced procedure.
White Paper

65. Viscous Damper Development and Future Trends

Viscous dampers can protect structures against wind excitation, blast and earthquakes. Viscous damper technology originated with military and aerospace applications. Approximately 20 years ago it was found that the same fluid viscous dampers that protect missiles against nuclear attack and guard submarines against near miss underwater explosions could also protect buildings, bridges and other structures from destructive shock and vibration. This paper describes fluid damper technology, analysis considerations, installation methods and development work in progress.
White Paper

63. Virtual Base Isolation by Building Softening with Drift Control Provided by Fluid Viscous Dampers

The paper describes “virtual isolation” for buildings with one or more soft stories. Using the 1999 SEAOC Blue Book (SEAOC, 1999) recommendations for passive energy dissipation, the building’s Lateral Force Resisting System (LFRS) is designed for strength requirements only, resulting in a relatively flexible LFRS, while Fluid Viscous Dampers (FVD) are incorporated to limit story drifts to acceptable levels. There are many benefits to this “virtual isolation” system. With the elimination of the maximum drift requirements, the moment frames are substantially lighter than a traditionally framed building, thus lowering the structural steel cost of the LFRS. The long period structure also produces significantly reduced forces in the foundation elements. Velocity and displacement are reduced significantly through the use of the FVDs, which protects the sensitive contents of the building. These benefits lead to a reduced response resulting in an enhanced performance level during a major seismic event.
Product Info

56. Buildings: Design for Damping

The end of the Cold War in 1990 heralded a restructuring period for the American military and defense industry. In the civil engineering field, high capacity fluid dampers have transitioned from defense related structures to commercial applications on buildings and bridges subjected to seismic and/or wind storm inputs. Because fluid damping technology was proven thoroughly reliable and robust through decades of Cold War usage, implementation on commercial structures has taken place very quickly. This paper provides a broad overview as well as a guide to implementation; with specific case studies for four of the more than 300 major buildings and bridges equipped with fluid dampers by Taylor Devices, Inc., a defense contractor from the Cold War years.
White Paper

55. Experimental Study of Bridge Elastomer and Other Isolation and Energy Dissipation Systems with Emphasis on Uplift Prevention and High Velocity Near-Source Seismic Excitation

A series of shake table tests on an isolated bridge model included low and high damping elastomeric isolation systems, and low damping elastomeric systems with added linear and nonlinear viscous dampers. Each of these configurations could withstand much stronger seismic excitations than the non-isolated configurations. A set of low intensity tests was conducted to form a basis for comparison with the non-isolated configurations and also to test the effectiveness of these systems under low intensity excitation. The results of these tests are presented, followed by a discussion of the effects of scragging, the benefits of seismic isolation, and the significance of damping, the importance of added damping in near source seismic excitation and on the benefits and drawbacks of using nonlinear viscous damping.
Product Info

54. Here’s How it Works

This article from Bridge Builder magazine shows how Taylor Devices dampers reduce seismic response of bridges.
White Paper

53. SEAOC Energy Dissipation Committee Appendix A: Guidelines for Buildings Using Passive Energy Dissipation Systems

This set of provisions provides minimum design requirements for the incorporation of passive energy dissipation devices in buildings. Energy dissipation devices (also termed damping devices) reduce global and interstory seismic displacement response of structural systems, but may either increase or decrease seismic stresses and accelerations within structural systems. They provide a controlled increase in structural damping, and may also result in an increase in structural stiffness or change in participating mass. Passive energy dissipation systems do not require active control by electrical, pneumatic or hydraulic systems. Buildings designed in conformance with these provisions must also be designed in accordance with all other applicable provisions of the Uniform Building Code, except as specifically defined in this appendix. Design must consider the combined behavior of all elements of both the Lateral Force Resisting System (LFRS) and the Energy Dissipation System (EDS). Energy dissipation devices must not form part of the gravity load – resisting system.
Technical Brief

50. Testing and Modeling of an Improved Damper Configuration for Stiff Structural Systems

This report describes a toggle brace damper system that adds significant damping to stiff structures, like reinforced concrete shear wall buildings. It is generally recognized that these stiff structural systems, such as reinforced concrete shear walls and steel braced dual systems, are characterized by small drifts and small relative velocities that make the implementation of seismic energy dissipation devices difficult. This report presents a study on a toggle brace damper system that magnifies the damper displacement and reduces the required damper force to produce the desired damping. The reports presents the concept, describes the theoretical treatment, and includes an experimental study with cyclic and shake table testing of a model structure along with procedures for response history and simplified analysis.
Technical Brief

49. Seismic Testing of a Building Structure with a Semi-Active Fluid Damper Control System

This paper describes shaking table tests of a multi-story scale model building structure subjected to seismic excitation and controlled by a semi active fluid damper control system. The semi active dampers were installed in the lateral bracing of the structure and the mechanical properties of the dampers were modified according to control algorithms which utilized the measured response of the structure. A simplified time delay compensation method was developed to account for delays within the control system. The results of shaking table tests are presented and interpreted and analytical predictions are shown to compare reasonably well with the experimental results. These tests included an undamped system, passive damping, and semi-active damping. Both the purely passive damper system and the semi-active system significantly reduced seismic response.
Case Study

48. Arrowhead Regional Medical Center

This article describes every aspect of the design and construction of the Arrowhead Regional Medical Center, including the use of base isolators and viscous dampers to insure continuous operation even after a major seismic event. The article even includes many of the financial aspects of this huge project.

Thank You!

A Taylor Devices Representative will be in touch shortly.