Uplift load–movement response of bell pier foundations in Gobi gravel

Abstract

The purpose of the study described in this paper was to investigate the load–movement behaviour of uplift-loaded bell pier foundations in Gobi gravel. In total, 40 full-scale field tests were carried out in Gobi gravel at seven sites in China. Both the site conditions and the load tests were documented comprehensively. Under tensile loading, the behaviour of the foundations followed a typical two-phase pattern. Normalising the measured load–displacement curves reduced the scatter in the curves. Furthermore, it was found that the normalised uplift load–movement behaviour of the foundations could be characterised by a hyperbolic model. Explicit hyperbolic curve-fitting constants were suggested for the foundations at the 50% and 95% confidence levels. The hyperbolic curve of the normalised load–displacement relationship for the foundations revealed a substantially stiffer response than that of spread footing foundations in backfilled soil.

Experimental Study on the Bearing Behavior and Failure Model of Digging Hold Foundation in Rock Ground

“…(3) The failure surface evolves from the foundation bottom extending towards the surface along a certain angle, which increases from 35.7 • to 42.5 • as the internal friction angle decreases from 56 • to 41 • . (4) The ratio between the equivalent shear strength in Chinese Code and uniaxial compressive strength falls in the range of 0.027-0.05.…”

“…It is worth mentioning that the tower foundation mainly bears the uplift force due to wind, wire gravity, etc. Thus previous researches employed high-cost field tests to study the uplift-bearing capacity of the digging hold foundations in sands [3][4][5], clays [6][7][8][9][10], and rocks [11][12][13][14][15]. The field experimental data have been applied to engineering practice, and great practical effects have been achieved.…”

Uplift Performance of Plate Anchors in Cement-Stabilised Aeolian Sand

“…Aeolian sands are fine to medium, non-plastic and uniformly graded materials in many sandy sites, mainly in desert areas, such as Xinjiang, Inner Mongolia, Ningxia, and Gansu Province in Northwest China. Electric transmission systems spanning from West to East China have been planned in recent years (Qian et al, 2014;Qian et al, 2015;Yang et al, 2019;Yang et al, 2020a;Yang et al, 2020b;Huang et al, 2020, Huang et al, 2021a, Huang et al, 2021b; therefore, foundations for four-legged lattice-type transmission towers need to be built in these aeolian sand regions. These tower foundations must resist both uplift and compression loading when subjected to permanent and transient load conditions (Pacheco et al, 2008).…”

Editorial

“…The fifth paper (Qian et al, 2014) describes the response of bell piers for lattice electricity pylon foundations in the Gobi Desert. Spread foundations were traditionally used with native soil backfill to provide mass for uplift resistance, however, bell piers minimise waste production and environmental damage and therefore provide an economic alternative with the wider 'bell' at the toe of the pier providing good tension capacity.…”