Stiffness of wall-type grouting under transversal loading

Soil treatment using jet grouting or deep mixing techniques can enhance the performance of existing embedded retaining structures by improving both ground strength and stiffness. Although the estimation of the equivalent geotechnical parameters of the composite ground is crucial for evaluating the effect of the improvement on the structures, current design methods are still highly empirical. Focusing on a wall-type treatment, two-dimensional numerical analyses using the finite-element method have been developed in order to evaluate the equivalent (untreated–treated soil) composite parameters. The results have been used to draw up a design chart which correlates the density of the treatment and the stiffness of the composite. Taking into account an existing quay wall these results demonstrate the beneficial effect of improvement treatment in the passive zone in terms of both geotechnical safety and mitigation of internal stresses.