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Home > Publications > International Concrete Abstracts Portal
Showing 1-5 of 10 Abstracts search results
Document:
102-S86
Date:
November 1, 2005
Author(s):
Matthew J. Schoettler, Jose I. Restrepo, Frieder Seible, and Ed Matsuda
Publication:
Structural Journal
Volume:
102
Issue:
6
Abstract:
The experimental testing of a bridge pier for seismic performance is presented in this paper. A typical bent of Bay Area Rapid Transit’s (BART’s) West Oakland Aerial Guideway was investigated at half scale. Two pseudo-cyclic bidirectional tests were conducted on a single test specimen modeling an existing pier including proposed retrofit measures. Twenty-four battered piles provided the foundation moment capacity during a system test. This test evaluated the likely failure mechanism of the pile-pile cap connection. The second test isolated the column-footing joint by restraining pile cap rotation and translation. In this test, retrofitted pile cap was evaluated for its joint shear response. The system test results indicated a limited system ductility after pile failure, followed by a rocking response of the pier. Results from the joint shear test indicated the retrofit was sufficient to prevent a joint shear failure and helped establish the allowable column-footing joint shear stress to use in retrofit design.
DOI:
10.14359/14793
94-S72
November 1, 1997
Thomas T. C. Hsu
94
New torsion design provisions have been proposed for the 1995 ACI Build-ing Code. As compared to the I989 provisions, these generalized I995 pro-visions have three advantages: First, they are applicable to closed cross sections of arbitrary shapes. Second, they are applicable to prestressed concrete. Third, they are considerably simplified by deleting the torsional concrete contribution and its interaction with shear: These new provisions are suitable for application to concrete guideways and bridges, because these large structures are always prestressed and are often chosen to have hollow box sections of various shapes. This paper discusses the back-ground of the new code provisions, suggests modifications to code formulas, and illustrates the application of the code provisions to prestressed hollow girders by way of a guideway example.
10.14359/9738
JL83-76
September 1, 1986
ACI Committee 358
Journal Proceedings
83
5
These recommendations for analysis and design of transit guideways, reported by Committee 3.58, form a procedure for the design of reinforced and prestressed concrete guideway structures for public transit use. The document is specifically prepared to provide design guidance for transit structures. For items not covered here, the reader is referred to appropriate bridge and railroad design codes.
10.14359/10676
JL80-36
September 1, 1983
Ching- Sheng Hwang and Thomas T.C. Hsu
80
Prestressed concrete double-T-girders, 80 ft (24.4 m) long, 12 ft (3.66 m) wide, 5 ft (1.52 m) deep, and 93 tons (85.3 metric tons), were adapted for the 21 mile (33.8 km) aerial guideway of the Dade County Rapid Transit System. These girders are subjected to large torsional moments caused by wind loads and the nosing/lurching action of vehicles. For the torsional design of these girders, a general method of mixed torsional analysis of channel-type, thin-wall open reinforced concrete sections was developed. This method was based on a mathematical approach using a Fourier Series. In a thin-wail open section subjected to torsion, warping torsional resistance must be considered in addition to the well-known St. Venant torsional resistance. The elastic mixed torsional analysis developed by V. Z. Vlasov is applicable only to reinforced concrete thin-walled sections before cracking. The Fourier Series method proposed is applicable to both the pre-cracking and the post-cracking analysis of such beams. o understand post-cracking mixed torsional behavior, both the post-cracking St. Venant torsional rigidity and the post-cracking warping torsional rigidity must be evaluated. Methods to evaluate post-cracking St. Venant torsional rigidity have been developed in recent years; however, methods to evaluate post-cracking warping torsional rigidity are still unavailable. A bi-material model to determine the post-cracking warping torsional rigidity is proposed.
10.14359/10861
JL80-37
Andrzej S. Nowak and Hid N. Grouni
Genrally, transit guideways have been designed using highway and railway bridge design codes. However, there are significant differences berween structures supporting highwuy and roadway traffic and those supporting transit vehicles, particularly, in values and variations of load components. This may result in uneconomical solutions for transit structures. The procedure used to develop criteria for the design of transit guideways is described. Five transit systems were selected. Load components and their variations were determined. Then, load and resistance factors were calculated. The acceptance criterion was closeness of the calculated liability indices to the target safety level. Safety is measured in terms of a reliability index, and design criteria were developed for the ultimate and serviceability limit states.
10.14359/10862
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