Physical-mechanical assessment of full-scale soil-cement column constructed in clayey soil

Jet grouting has recently become a soil improvement method used to solve most soil problems. In this study, seven full-scale soil–cement (SC) columns were constructed in clayey soil with different pressure injections (300, 325, 350, 375, 400 bar), jet grout rotations (25, 35, 45 rpm) and a w/c ratio of 1. These parameters were used to examine the geomechanical properties of the SC, such as strength characteristics (UCS and UPV), and SC–soil surface friction. The physical properties were observed by evaluating the water absorption rate, density, and porosity. The diameter variation was analysed to determine the effect of both parameters on SC diameter. The geomechanical properties of the grout columns generally varied with pressure and rotation. The average strength variation for pressure and rotation was 38% and 9%, respectively. The average water absorption percentage was 13% and 22%; the average density was 8% and 11%; the average porosity was 6% and 10%, respectively. The maximum surface friction angles were 19° and 18° for SC350–35 and SC400–45, respectively. This study theoretically predicts the diameter of the grout column for construction in clayey soil.