Amir Hamidi, S. Mohsen Haeri,
Volume 6, Issue 3 (September 2008)
Abstract
The deformation and stiffness characteristics of a cemented gravely sand was investigated using
triaxial equipment. The triaxial tests were conducted in both dry and saturated undrained conditions.
Artificially cemented samples are prepared using gypsum plaster as the cementing agent. The plaster was
mixed with the base soil at the weight percentages of 1.5, 3, 4.5 and 6. The applied confining pressure varied
between 25 to 500 kPa in triaxial tests. The process of yielding of the soil was investigated for the considered
soil and the bond and final yield points were identified for the cemented soil with different cement contents.
The variations of deformation and stiffness parameters with cement content and confining stress were studied
as well. Some of the parameters were determined for both drained and undrained conditions to investigate the
effect of drainage condition on the stiffness and yield characteristics of the tested cemented gravely sand.
According to the results, the difference between drained and undrained tangent stiffness decreases with
increase in confining stress. Finally the effect of cement type was investigated as an important parameter
affecting the stiffness at bond yield. The rate of increase in tangent stiffness at bond yield changes with cement
content for different cementing agents.
Ali Kavand, S.mohsen Haeri, Arian Asefzadeh, Iraj Rahmani, Abbas Ghalandarzadeh, Ali Bakhshi,
Volume 12, Issue 3 (Transaction B: Geotechnical Engineering, July 2014)
Abstract
In this paper, different aspects of the behavior of 2×2 pile groups under liquefaction-induced lateral spreading in a
3-layer soil profile is investigated using large scale 1-g shake table test. Different parameters of the response of soil and piles including time-histories of accelerations, pore water pressures, displacements and bending moments are presented and discussed in the paper. In addition, distribution of lateral forces due to lateral spreading on individual piles of the groups is investigated in detail. The results show that total lateral forces on the piles are influenced by the shadow effect as well as the superstructure mass attached to the pile cap. It was also found that lateral forces exerted on the piles in the lower half of the liquefied layer are significantly larger than those recommended by the design code. Based on the numerical analyses performed, it is shown that the displacement based method is more capable of predicting the pile group behavior in this experiment comparing to the force based method provided that the model parameters are tuned.
