Earthquake resistant structures

About: Earthquake resistant structures is a research topic. Over the lifetime, 1126 publications have been published within this topic receiving 27467 citations.

Earthquake Resistant Design Using Friction Pendulum Connections

Abstract: The Friction Pendulum System (FPS) offers a simple approach for increasing a structure's earthquake resistance. The approach uses steel connections which absorb earthquake vibrations using small amplitude pendulum motions. The FPS connections can permit the building frames to resist severe seismic forces on an elastic strength basis, with only minimal impact on the construction cost. This paper discusses the design approach, FPS performance, an example design, and design details.

Performance-Based Seismic Design of an Industrial Storage Rack System

Abstract: Performance-based methodologies are becoming the norm for seismic design and evaluation of building structures, recognizing that designs based on conventional code methodologies may result in inconsistent seismic performance. However, use of these methodologies is not as widespread for non-building structures, which may pose unique structural problems that can also benefit from a performance-based design and evaluation approach. This paper presents performance-based seismic design of a proprietary self-supporting enclosed industrial storage rack system with a box-type steel structure whose exterior dimensions can be varied to accommodate required storage space and geometric constraints. The lateral load resisting system comprises moment resisting frames with bolted connections in one direction and a combination of moment resisting frames and corrugated panels welded to the columns in the orthogonal direction. Three-dimensional nonlinear finite-element models are developed for structural analysis. Structural adequacy is evaluated through (1) AISC-LRFD criteria using a linear response-spectrum analysis and (2) performance-based provisions of FEMA 356 and FEMA 450 for life safety using a nonlinear pushover analysis. The results of the structural evaluation indicate that for more than half of the configurations, the performance-based criteria control the design and rack content weight capacity. Relying solely on elastic analysis and the LRFD design requirements, while satisfying code requirements, leads to structures that violate performance requirements in terms of excessive beam plastic rotations and column axial forces, indicating potentially poor performance during actual seismic events. Furthermore, P-delta effects, in conjunction with large plastic deformations and column compressive loads, significantly reduce the content weight capacity for taller systems with some configurations being disqualified for high seismic regions.

Risk Management for Seismic Retrofit of a Long-Span Truss Bridge Applying Damage-Controlled Design

Abstract: The Minato Bridge is a long-span truss bridge with a length of 980m and located in the Hanshin Expressway at the Osaka Port, Japan. Although damage to this bridge from the 1995 Hyogo-ken Nanbu Earthquake had not been so serious, design seismic force for highway bridges was revised after the earthquake. Seismic performance of the bridge was evaluated by dynamic analysis applying revised ground motions and its seismic risk was found to be at non-negligible level. In this project, several types of retrofit structural systems with three different performance levels were considered and evaluated using seismic life-cycle cost (S-LCC). S-LCC consists of retrofitting cost and seismic risk. Several risks were calculated using the damage probability obtained from the hazard and fragility curves as well as cost data. As a result, the damage-controlled structure with minimized S-LCC was employed to achieve rational retrofit from a view point of risk management. The concept was to differentiate main members which support vertical load from sub-members for lateral force such as seismic force. In this design, main members were required to be within linear region and sub-members were allowed to perform nonlinearly to provide damping. This structural system should allow early reopening of the bridge to traffic even after a severe earthquake so that it will serve as a part of lifeline and reduce social loss.

Experiences with Friction Pendulum TM seismic isolation in California

Abstract: Seismic isolation shines as the top performance system for earthquake resistant structures, having involved a large variety of essential facilities since the late 1980s. Within the available devices, friction pendulum bearings present beneficial dynamic characteristics which are not intrinsically provided by other isolation systems. Developed and engineered by Earthquake Protection Systems, Inc. in California, these bearings have become a popular choice for designers. This paper firstly presents the experience of Skidmore, Owings & Merrill LLP (SOM) on the design of friction pendulum base isolated buildings, with systems evolving from the single concave to the Triple Friction Pendulum TM