Numerical analysis of jet grout blanket application in excavation support systems

Alternative methods are being investigated for safe and economical design of deep excavation support structures. As the excavation depth increases, the lateral strength capacities remain low according to soil types, which is a current problem in our country. The usage of jet grout columns, which are frequently preferred in soil improvement works, is offered as an economical solution applied like a heel and plate below the final excavation level, as it increases stability and improves excavation performance. In this study, a parametric study was carried out on the effects of the jet grout blanket system on the deep excavation structure, with Plaxis 2D based finite element method. In analysis; 7 different projects were used in which the vertical excavation support element and the soil profiles are different. A total of 21 model were analyzed, combinations were made with different elasticity modules in varying lengths and widths from the final excavation level of the jet grout columns to the bottom of the vertical excavation element. It was observed that the basal heave at the base decreased, the static forces on the excavation support structure decreased and the horizontal displacements on the wall decreased. When the results are examined, the use of jet grout heel and jet grout blanket applications in excavation support systems has been evaluated as an innovative and applicable method. Keywords: Excavation support system, Jet grout blanket, Plaxis 2D, Basal heave.