Drilling and Grouting to Allow Excavation Works in a Challenge Ground Condition

The activities for the construction of the Sail Tower, Jeddah, KSA, comprised piling, shoring (diaphragm wall, tie-back anchors and dewatering) and excavation works, including all related underground works for the foundation structure of the new building. Taking into account the severe hydro-geological condition, a grout blanket was designed to reduce the coralline limestone permeability in order to decrease notably the water inflow from the bottom of the excavation. With the grouting blanket in place and some wells for the dewatering purpose, the excavation within the structural diaphragm wall was performed under almost dry condition. This document describes the site proceeding and the results achieved at completion of grouting works, during dewatering and excavation works and some outlines related to the procedures and checks implemented for the grouting activity quality control.