Jet grouting is a developing technology for soil improvement in most soil types. It offers advantages such as relatively short execution and a high volume of soil rehabilitation. Nonetheless, due to the complexity of this method, related scientific research is ongoing. This study presents a design and fabrication process for equipment capable of constructing soil–cement columns using a high-pressure injection mechanism at the laboratory scale. The columns are constructed using the device in Firouzkouh 161 silica sand. The effect of energy on the diameter of the columns constructed at laboratory scale is evaluated. The behaviour of such columns built using full-scale elements is evaluated using resistance testing on core-sampling specimens. The results showed that an increase in pressure injection leads to logarithmic growth in the diameter of the element. It was found that an increase in pressure had a greater effect on the diameter than an increase in injection duration. The uniaxial compressive strength of the specimens showed a 35% decrease in the horizontal core in comparison with the vertical core. The compressive strength of columns without core sampling was 2.3–2.5 times that of the columns with core sampling.