M.h. Baziar, Sh. Salemi, T. Heidari,
Volume 4, Issue 3 (9-2006)
Abstract
Seismic behavior of a rockfill dam with asphalt-concrete core has been studied utilizing
numerical models with material parameters determined by laboratory tests. The case study selected
for these analyses, is the Meyjaran asphalt core dam, recently constructed in Northern Iran, with
60 m height and 180 m crest length. The numerical analyses have been performed using a nonlinear
three dimensional finite difference software and various hazard levels of earthquakes.
This study shows that due to the elasto-plastic characteristics of the asphalt concrete, rockfill dams
with asphalt concrete core behave satisfactorily during earthquake loading. The induced shear
strains in the asphalt core, for the case presented in this research, are less than 1% during an
earthquake with amax=0.25g and the asphalt core remains watertight. Due to large shear
deformations caused by a more severe earthquake with amax=0.60g, some cracking may occur
towards the top of the core (down to 5-6 m), and the core permeability may increase in the top part,
but the dam is safe.
A. Asakereh, S.n. Moghaddas Tafreshi, M. Ghazavi,
Volume 10, Issue 2 (6-2012)
Abstract
This paper describes a series of laboratory model tests on strip footings supported on unreinforced and geogrid-reinforced sand
with an inside void. The footing is subjected to a combination of static and cyclic loading. The influence of various parameters
including the embedment depth of the void, the number of reinforcement layers, and the amplitude of cyclic load were studied.
The results show that the footing settlement due to repeated loading increased when the void existed in the failure zone of the
footing and decreased with increasing the void vertical distance from the footing bottom and with increasing the reinforcement
layers beneath the footing. For a specified amplitude of repeated load, the footing settlement is comparable for reinforced sand,
thicker soil layer over the void and much improved the settlement of unreinforced sand without void. In general, the results
indicate that, the reinforced soil-footing system with sufficient geogride-reinforcement and void embedment depth behaves much
stiffer and thus carries greater loading with lower settlement compared with unreinforced soil in the absent of void and can
eliminate the adverse effect of the void on the footing behavior. The final footing settlement under repeated cyclic loading becomes
about 4 times with respect to the footing settlement under static loading at the same magnitude of load applied.
