scholarly journals Evaluation of Cyclic Shear Strength Characteristics of Sands Containing Fines

2012 ◽  
Vol 28 (7) ◽  
pp. 31-40 ◽  
Author(s):  
Uk-Gie Kim ◽  
Dong-Wook Kim ◽  
Joon-Yong Lee ◽  
Ju-Hyong Kim
Author(s):  
N. Yoshimoto ◽  
M. Hyodo ◽  
Y. Nakata ◽  
R. P. Orense ◽  
H. Murata

1984 ◽  
Vol 30 (106) ◽  
pp. 348-357 ◽  
Author(s):  
W.G. Nickling ◽  
L. Bennett

AbstractThe effect of ice content and normal load on the shear strength characteristics of a frozen coarse granular debris was investigated. 31 shear tests were carried out in a modified shearbox allowing a sample temperature of (–1.0 ± 0.2)° C and a load rate of 9.63 × 10−4 cm/min. The tests showed that as the ice content of the frozen debris was increased from 0% (under-saturated) to 25% (saturated), sample shear strength was markedly increased. In contrast, sample shear strength was reduced as ice content was increased from 25% (saturated) to 100% (supersaturated). The changes in shear strength with increasing ice content were attributed directly to changes in internal friction and the cohesive effects of the pore ice. The shear tests also indicate that shear strength increases with increasing normal load up to a critical limit. Above this limit, dilatancy is suppressed causing the shear strength to decrease or remain relatively constant with increased normal load.The stress-strain curves of the 31 tests indicated that samples with higher ice contents tended to reach peak strength (τP) with less displacement during shear. Moreover, the difference between τp and τr (residual strength) was lowest for pure polycrystalline ice and highest for ice-saturated samples. The Mohr-Coulomb failure envelopes displayed very distinctive parabolic curvilinearity. The degree of curvature is thought to be a function of ice creep at low normal loads and particle fracture and crushing at high normal loads.


2021 ◽  
Vol 13 (23) ◽  
pp. 13224
Author(s):  
Hyeong-Gook Kim ◽  
Yong-Jun Lee ◽  
Kil-Hee Kim

This study presents a strengthening method for reinforced concrete (RC) columns. The proposed method, which consists of a pair of steel rods, two reverse-threaded couplers, and four corner blocks, is feasible and straightforward. A quasi-static cyclic loading test was performed on the columns externally strengthened by the steel rods. It was found that the corner blocks and the external steel rods with a low prestress level effectively confined the concrete on the compression side of plastic hinges, which eventually induced flexural failure with a ductility higher than three in the strengthened columns. In addition, an analytical approach to predict the shear strength and ultimate flexural strength of the externally strengthened columns was applied. The comparison of analytical and experimental results showed that the analytical approach provided highly accurate predictions on the maximum strength and the failure mode of the externally strengthened columns. It is expected that the application of the proposed method will improve the seismic performance of damaged or deteriorated RC structures, thereby increasing their lifespan expectancy and sustainability.


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