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.

Ductile Connections for Precast Concrete Frame Systems

Abstract: This paper describes a research program to investigate the behavior of ductile connections between precast beam-column elements. Eight beam-column connections were tested to characterize the overall behavior of the connection details. Each connection specimen was designed to incorporate one of three behavioral concepts in the connection elements: tension/compression yielding, substantial energy dissipation, or nonlinear-elastic response. Based on the behavioral information collected during connection tests, analytical models were developed to investigate the behavior of complete precast frame systems. Results of the experimental study and preliminary results of the analytical work are presented. The objective of the program is to provide rational design recommendations for engineers to detail precast frame connections for use in regions of seismic risk.

Ductility of Prestressed and Partially Prestressed Concrete Beam Sections

Abstract: D analyses of structures responding elastically to ground motions recorded during severe earthquakes have shown that the theoretical response inertia loads are generally significantly greater than the static design lateral loads recommended by codes. Hence, structures designed for the lateral earthquake loads recommended by codes can only survive severe earthquakes if they have sufficient ductility to absorb and dissipate seismic energy by inelastic deformations.'-" Prestressed concrete has been widely used for structures carrying gravity loads but has not had the same acceptance for use in structural systems which resist seismic loading. Part of this caution in the use of prestressed concrete for earthquake resistant structures has been due to the paucity of experimental and theoretical studies of prestressed concrete structures subjected to seismic type loading. A survey of the research which has been conducted on the seismic resistance of prestressed concrete was published in 1970. 9 Parmeio and Hawkins" have published more recent reviews of the state of the art of seismic resistance of prestressed and precast concrete. There has been a lack of detailed building code provisions in the United States for the seismic design of prestressed and precast concrete. For example, the ACI Code,' the SEAOC recommendations, 2 the Uniform Building Code, 3 and the tentative provisions of the ATC 4 all contain special provisions for the seismic design of cast-in-place reinforced concrete structures, but do not have

Seismic Behavior of Micropiles: Used as Foundation Support Elements: Three-Dimensional Finite Element Analysis

Abstract: Presented is a three-dimensional finite element analysis of the seismic behavior of micropiles used in engineering applications, such as construction in earthquake areas, and seismic retrofitting of structure foundation and retaining systems. It is composed of two parts. The first is concerned with analysis of the seismic behavior of a single micropile supporting a superstructure; results obtained with three-dimensional finite element modeling are compared to those obtained from a simplified model based on the Winkler approach. The second part includes a study of the seismic behavior of groups of micropiles. Numerical simulations are conducted to study the variation of the group effect with the variation of micropile spacing, number of micropiles, and the position of the micropile in the group. Analysis of results of numerical simulations shows that the presence of the superstructure induces significant inertial effect, which causes a high increase in the bending moment in the upper part of micropiles; th...

Shearwalls - an answer for seismic resistance?

Abstract: The highlights are presented of observations of the behavior of buildings containing shearwalls in the earthquakes of the last 30 years. The earthquakes discussed here include the following: Chile (1960); Skopje, Yugoslavia (1963); Caracas, Venezuela (1967); San Fernando, California (1971); Managua, Nicaragua (1972); Bucharest, Romania (1977); Mexico City (1985); Chile (1985); and Armenia (1988). During these earthquakes, buildings containing shearwalls exhibited extremely good earthquake performance. In most cases, the shearwalls were reinforced in the traditional manner for gravity and overturning, without consideration to special details for ductility, as required in recent U.S. codes. Investigatitons of the behavior of modern structures in a dozen earthquakes throughout the world since 1963, has not revealed a single concrete building containing shearwalls that has collapsed.