An investigation on the contribution of jet grout strutting to thestability of deep retaining systems by finite element method

Jet grouting columns are used to enhance stability of deep retaining systems, to improve safetyof excavations and to constitute stable structures. Depending on properties, lateral resistance ofthe soil below excavation level can sometimes be insufficient. The need of improvement of thelateral stability of deep retaining walls ongoing subway structures is a current problem. In orderto eliminate this problem economically, horizontal support systems can be formed below thelevel of excavation by the application of jet grout columns.In this thesis, the contribution of jet grout strutting to the stability of deep retaining system isstudied by finite elements analyses. For this purpose, engineering properties of jet grout columnsare investigated and structural uses are mentioned. The geometry of the problem used in theanalyses has been inspired by İzmir Karşıyaka Subway Tunnel Construction Project.Combinations of analyses are formed by changing strength characteristics, treated soil area ratios,patterns and location types of jet grouted columns. Analyses are made for sandy and clayey soilprofiles seperately. Plaxis 2D and 3D finite element programs are employed in the analyses. Theresults of analyses in terms of displacements and moments of diaphragm wall are presentedcomparatively. Also vertical soil displacements at both natural ground surface and excavationlevel are presented.