The influence of the rammed stone column formation on strength parameters of the surrounding soil

This paper presents the results of field tests performed to examine the influence of the rammed stone column formation process on the surrounding soil. The influence is expressed by cohesion and internal friction angle changes. These parameters were determined in cone penetration test (CPTU) performed during and after the stone column formation process. The conducted tests have shown that the process of column formation affects the strength parameters of the surrounding soil. These changes are complex and come from a number of factors such as initial in situ soil characteristics, distance from the column and time. The field tests indicated a decrease in strength parameters during column formation process. Subsequently, when soil structure is rebuilt and consolidation process takes place, the strength parameters increase.