The air permeability of soil generally refers to the rate which water diffuses through the soil and airflows through the soil. Currently

underground railroads

largc-scale underground structures and pipelines in developed countries adopt the shield method. Generally

this method needs air pressure to stabilize the digging. Subsurface

therefore it is critical to control the permeability of the soil. This paper is based on the results of the permeability experiment at Taipei basin. The detailed analysis of the results leads to the derivation of the respective permeability.