土层透气性现场实验与分析

In-situ test and analysis of air permeability of soil

压力气体在土中之渗透性问题是一个地下工程施工技术所面临的一个新课题。目前,先进国家建设地下铁路,大型地下结构物或大型地下管道系统时多采用盾构法施工。而以压力平衡盾构前端开挖面时,可用水压平衡或气压平衡法。在气压平衡法施工时,如何撑握土壤的稳透气状况非常重要。本文介绍了台北盆地一现场透气实验的步骤和方法,并引入场地透气系数和漏气系数的概念对试验结果加以分析。

The air permeability of soil generally refers to the rate which water diffuses through the soil and airflows through the soil. Currently, underground railroads, large-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. The results of the permeability experiment at Taipei basin were analyzed.