Edinburgh Napier University

  Ground improvement methods are increasingly being used as means
to control settlements and improve the shear strength of foundation soils. The compaction grouting (CG) method is a ground improvement method that is used as means to mitigate or even remediate excessive settlements in existing structures. The use of this method causes minimum disturbance to the structures; therefore, it is an appropriate application for those structures. The objective of this publication is to investigate the advantages and limitations of CG as a repair solution in situations where the foundation soil is composed of very compressible solid waste landfill material. The investigation is conducted by means of a case study that includes a 40.000 square meter (m2) commercial centre founded on a previous compressible material and subjected to excessive differential settlements. It includes description of the installation as well as monitoring during and after construction of 1800 CG columns, each having a depth of 15 meters. The data collected from the monitoring systems are used to determine the rate, pressure and volume of injected grout required to achieve the target amount of densification of the foundation soil for a selected treated area.