Controlled Curved Drilling Technique in the Permeation Grouting Method for Improvement Works of an Airport in Operation

Improvement of the ground under existing structures against liquefaction is not easily possible. A new controlled curved drilling method is developed to apply the permeation grouting of chemicals to the liquefiable ground under existing structures. This method is employed for the improvement work of Tokyo International Airport. Details of application of this new method are presented in this paper. The precise monitoring system during the improvement work for prevention of any potential accident during the improvement work is also demonstrated. The post-improvement investigations showed that application of permeation grouting method by means of controlled curved drilling technique can effectively and safely improve the ground.