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Showing papers on "Earthquake resistant structures published in 1980"


Book
01 Jan 1980

57 citations


Journal ArticleDOI
TL;DR: A survey of the research which has been conducted on the seismic resistance of prestressed concrete was published in 1970 as mentioned in this paper, and more recent reviews of the state-of-the-art of seismic resistance have been published by Parmeio and Hawkins.
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

29 citations




Journal ArticleDOI
TL;DR: The development of rubber structural bearings for civil engineering applications is described in this article, where a formula for the compression modulus in terms of the shape factor of the rubber block is given.

16 citations


Journal ArticleDOI
01 May 1980

11 citations





01 Jan 1980
TL;DR: In this article, a closed-form solution for determining bending moments and axial loads for tunnels and shafts under earthquake load, while considering soil-structure interaction as a pseudostatic problem, is presented graphically in terms of non-dimensional parameters, such that these curves can be used directly to aid in design-load calculations.
Abstract: This paper presents a closed-form solution for determining bending moments and axial loads for tunnels and shafts under earthquake load, while considering soil-structure interaction as a pseudostatic problem. The results are presented graphically in terms of nondimensional parameters, such that these curves can be used directly to aid in design-load calculations. The solutions are particularly useful for relatively rigid structures embedded in soft soils, or for tunnels/shafts with small segment lengths.

6 citations





Journal ArticleDOI
TL;DR: In this paper, two buildings, one a masonry bearing wall and heavy timber floor warehouse and the other a reinforced concrete flat slab factory, are studied to determine the existence of weak links in seismic resistance and the cost of upgrading such resistance during major renovations.
Abstract: A particular opportunity to upgrade the seismic resistance of existing buildings arises when their lifetime is extended by major renovations. There is lacking, however, a set of guidelines that relates the cost of strengthening a structure to the probable reduction in earthquake-induced damage and life loss. This paper offers a recommendation for strengthening buildings undergoing renovations in zones where intensity of expected seismic shaking is low. Two buildings, one a masonry bearing wall and heavy timber floor warehouse and the other a reinforced concrete flat slab factory, are studied to determine the existence of weak links in seismic resistance and the cost of upgrading such resistance during major renovations. The expected damage from three levels of earthquake for the two buildings is summarized in damage probability matrices; these matrices are then used to compute mean damage ratios (MDR). Each MDR is shown as a function of strengthening cost, providing a means for estimating the reduction in seismic risk of these buildings from their present condition when they are either strengthened to a recommended practical level or replaced with new construction.





01 Nov 1980
TL;DR: In this article, geologic and seismological reasons for patterns of guidance alarms in Minuteman Wing V due to the 1975 Pocatello Valley, Idaho and 1979 St Elias, Alaska earthquakes are examined.
Abstract: This study examines geologic and seismological reasons for patterns of guidance alarms in Minuteman Wing V due to the 1975 Pocatello Valley, Idaho and 1979 St. Elias, Alaska earthquakes. Two features are identified which together could cause these patterns of alarms. First is the existence of lightly-damped missile suspension system modes in the period window from 2 to 6 seconds. Second is a 2 to 3 km sedimentary layer underlying the wing, with natural frequencies in this critical period window. Near-verticallyincident P and S seismic body waves which propagate directly from the source through the crust and upper mantle can interact with this structure. A Haskell-Thomson program for body wave propagation in a layered model indicates that peak ground shaking can vary by a factor of 2 at adjacent Wing V flights. Differences are due to variations in sediment thicknesses and wavespeeds, deduced from oil well log and laboratory data. Therefore, Wing V alarm patterns appear to be caused by the coincidence of three factors: 1) high gain of the 2 to 6 second suspension system modes; 2) incident body waves in this period range; and 3) sedimentary column resonance periods close to the suspension system natural periods. If the first two are sufficient to trigger alarms, then the third would cause anomalous patterns due to relative amplification between flights. Escarpments, basin edges and similar features are not likely to cause the observed distribution of alarms because they produce resonances at periods too short to affect the Missile Guidance Set. This is confirmed by a finite element analysis of the escarpment for verticallyincident body waves.

01 Nov 1980
TL;DR: In this article, an analytical approach is proposed for seismic design evaluation of earth structures like foundations and slopes, based on random vibration principles, which can be directly used to evaluate seismic design inputs defined in terms of response spectra curves.
Abstract: An analytical approach is proposed for seismic design evaluation of earth structures like foundations and slopes. The approach is based on random vibration principles. Seismic design inputs defined in terms of response spectra curves can be directly used. For verification of the proposed approach a comparative study of the results obtained by a rigorous nonlinear analysis approach and the proposed approach is conducted. It is observed that the proposed approach will provide a safe and conservative evaluation of an earth structure design for earthquake induced ground motions.