Static and Dynamic Tests of Buried Unreinforced Concrete Arches

Static and Dynamic Tests of Buried Unreinforced Concrete Arches
Author: William J. Flathau
Publisher:
Total Pages: 42
Release: 1966
Genre: Concrete arches
ISBN:

The primary objective of the study was to determine the response, to collapse, of buried semicircular, unreinforced concrete fixed-end arches of varying stiffnesses when subjected to both static and dynamic loads.

Static Tests of Shallow-buried Reinforced Concrete Arches

Static Tests of Shallow-buried Reinforced Concrete Arches
Author: Frank D. Dallriva
Publisher:
Total Pages: 242
Release: 1988
Genre: Concrete arches
ISBN:

The determination of the loads on and behavior of shallow-buried arch structures is complicated by the geometry of the arch and by existence if soil structures arches interaction effects. A common approach to the analysis of buried is to idealize the structure as a lumped parameter single degree of freedom (SDOF) system. The parameters which must be assumed for input into the SDOF model include a loading function and a structural resistance deflection relationship. The applied load on a buried arch due to overpressure at the ground surface includes a radial and a tangential component. The radial component can be measured experimentally; however, there seems to be no available transducers to measure the tangential component or interface friction. Two 1/12-scale model reinforced concrete arches were tested statically in a sand backfill. The arches were semicircular with an inside radius of 1 foot 9 inches and a thickness of 2 inches. One arch was covered with two layers of 1/32-inch-thick Teflon at the soil-structure interface to significantly reduce the interface friction, and the loading and behavior of the two arches were compared. Pretest finite element calculations were conducted to estimate the arch behavior. Based on both the experimental data and posttest calculations, it appears that interface friction on a shallow buried arch has an effect on its behavior, at least for the case of static loads. The load path at sections in the arch with a lower friction coefficient at the interface tended more toward pure compression than it did in the other arch. Keywords: Air blast simulation; Concrete structures; Hardened installation. (SDW).

Similitude Study of Flexible Buried Arches Subjected to Blast Loads

Similitude Study of Flexible Buried Arches Subjected to Blast Loads
Author: Jimmy P. Balsara
Publisher:
Total Pages: 168
Release: 1968
Genre: Aluminum
ISBN:

The objective of the study was to investigate and verify model-to-prototype scaling relations for blast loaded buried arches that respond both elastically and inelastically. Four geometrically similar, semicircular aluminum alloy arches with 4-, 8-, 12-, and 36-inch diameters were buried in dense dry sand and subjected to air-blast-induced loads on the surface. The tests were conducted at the Large Blast Load Generator located at the U.S. Army Engineer Waterways Experiment Station. The results of two series of tests, each consisting of 3 repeated shots, ranging from 70 to 300 psi, are presented. Within the range of parameters investigated, the scaling of the dependent variables were adequately verified. These variables included acceleration, velocity, displacement, thrust, and bending moment. (Author).

Failure of Footing-supported Buried Steel Arches Loaded Statically

Failure of Footing-supported Buried Steel Arches Loaded Statically
Author: John F. Munn
Publisher:
Total Pages: 90
Release: 1970
Genre: Concrete footings
ISBN:

The objective of this investigation was to study the failure of statically loaded steel circular arches buried in sand as affected by three variables; footing width, arch flexibility, and depth of burial. Static tests were performed on 16 arches with 18-inch outside diameters. The parameters varied were wall thickness, depth of burial, and footing area. The maximum static overpressure available was 100 psi. Strain measurements were made at various locations on the arch so that thrusts and moments could be computed. (The computer program developed for these computations is described in Appendix B.) Measurements of crown deflection and footing settlement were also made. Three modes of failure were observed in the various tests. Buckling of the crown of the arch and punching of the footings into the supporting soil were the two dominant failure modes, but buckling of the arch haunches also occurred in the case of the thin arch with large footings. Generally, it was observed that the thin arches with large footings exhibited arch failure while the thick arches with small footings exhibited footing failure. Based on the test results, a method was proposed for predicting the type of failure occurring for arches with various footing and arch stiffness configuration combinations. Support investigations were conducted to determine the properties of the sand and steel used in the test. Sand properties are described in Appendix A. (Author).