Advanced application of the jet-grouting technique in Bulgarian geotechnical practice

The primary objective of this paper is to showcase the versatile application of jet-grouting as a comprehensive approach for enhancing both structural integrity and soil behavior. This will be achieved by presenting practical examples of its successful implementation within the field of geotechnical engineering in Bulgaria, taking into account the unique local soil conditions. Jet-grouting is a well-acknowledged method for cement soil stabilization, involving the utilization of high-pressure water or cement suspension jets, enveloped in air, to erode and subsequently reconfigure the soil surrounding a borehole. The mechanical properties of the resultant medium are intricately linked to the local soil characteristics and various technical parameters associated with the jet-grouting system, including the number of nozzles, treatment duration, pressure, and fluid composition, among others. Remarkably, the existing design practices in Bulgaria, except for EN 12716:2003, do not offer specific directives or recommendations concerning the execution and quality control of the jet-grouting technique. Consequently, this paper not only aims to advocate best practices for the adoption of jet-grouting in the Bulgarian context but also seeks to elucidate the expected mechanical properties under diverse local soil conditions.