Quality control of jet grouting on the Cairo metro

This paper presents a review of the jet grouting works of Line 2 of the Greater Cairo metro system. During the project over 80 000 m³ of ground was treated using the jet grouting method, making this one of the largest jet grouting endeavours worldwide to date. Demanding design requirements for the various jet grouting applications coupled with the difficult Cairo ground conditions provided new challenges to the current jet grouting technology. Inherent difficulties with jet grouting were identified when relying on the method for watertightness at great depths. This paper summarizes the main jet grouting applications used on Line 2 of the Cairo metro and the quality control solutions implemented to overcome difficulties in the work.