Soil improvement with vibrated stone columns—influence of pressure level and relative density on friction angle

Numerical modelling of stone columns beneath a rigid footing

“…Typical values of ϕc=45º and c =15º were chosen. Those are usually peak values because the column material is compacted by the vibrator and is in a dense state [23]. Those values are assumed as material constants because a perfectly plastic model is used here.…”

“…Although the crushed stone (gravel) used for the column backfill is a pure frictional material, a small cohesion (cc=0.1 kPa) was used to avoid numerical problems. The reported values of the friction and dilatancy angles of the column backfill are usually just reasonable estimations of the "in-situ" properties, because it is very difficult to measure them in the field [23]. Typical values of ϕc=45º and c =15º were chosen.…”

Numerical study on bearing capacity of single stone column

“…On the other hand, White et al [16] showed the tamping method would produce stiffer columns with higher friction angle, thus resulted in higher bearing capacity than that obtained with vibration method. Herle et al [17] demonstrated the importance of maximum densification for the construction of the stone column. The literature has shown stone column friction angle can vary from 35° to 52° [6,18,19].…”

A web-based information system for geoconstruction technologies and performance of stone column reinforced ground

“…Herle et al (2009) also found that during densification, grain crushing and segregation take place, which results in a decrease in the void ratio. The study found that most cases result in friction angles above 50° and that design methods should utilize a value in this range, as compared to conventional designs, which use a friction angle of approximately 40° (Herle et al 2009).…”

“…The installation effects are not limited to the in situ soil. The influence of installation technique on the property of the stone column materials was studied by Herle et al (2009).…”