This work investigated the behavior of embankment models resting on soft soil reinforced with ordinary and encased stone columns (ESCs). Model tests were performed with different spacing distances between stone columns and two length-to-diameter ratios (L/d) of the stone columns, in addition to different embankment heights. A total of 39 model tests were performed on soil with an undrained shear strength of ≈10 kPa. The system consisted of a stone column–supported embankment at different spacing-to-diameter ratios (s/d) of stone columns. Earth pressure cells were used to measure directly the vertical stress on the column for all models, and another cell was placed at the base of the embankment between two columns to measure directly the vertical stress in reinforced soft soil. For embankment models constructed on soft clay reinforced with ESCs, it was found that whether a column was floating or end bearing (resting on a rigid stratum), encasement of the column by a geogrid was most effective in i...

The present work deals with helical piles that extensively used in foundations for structures subjected to both compressive and tensile forces. The behavio

Gypseous soils are considered one of the most problematic soils. The skirted foundation is an alternative technology that works to improve the bearing capacity and reduce settlement. This paper investigates the use of square skirted foundations resting on gypseous soil subjected to concentric and eccentric vertical load with eccentricity values of 4, 8, and 17 mm in 16 experimental model tests. To obtain the results by using this type of foundation, a small-scale physical model was designed to obtain the load–settlement behavior of the square skirted foundation; the dimension of the square footing is 100 mm × 100 mm with 1 mm thickness, the skirt depth ( D _s ) was 0.5, 1, and 1.5 B (where B is the footing width). The footing rests on dry gypseous soil with a relative density of 33%. The tests show that the gypsum content of the soil is 59%. The result shows that the highest bearing capacity for the square shape footing with D _s / B = 1.5 subjected to concentric load results in an improvement ratio of 190%. For the eccentric load, with D _s /B = 1.5, the increase in bearing capacity is about 120% at e = 8 mm when compared with using a foundation without a skirt.