针对目前国内软弱地层隧道施工中广泛采用的管棚超前支护辅助工法，从软弱地层水平钻孔的难度出发，分析了影响钻孔弯曲的三个主要因素，综合阐述了软弱地层浅埋暗挖施工中管棚法的水平钻孔技术，提出了水平钻孔的测斜、防斜和纠斜方法。并以南京地铁珠鼓区间大管棚施工实例为基础，说明了套管螺旋钻进工艺的应用效果。

At present piperoof advance reinforcement is widely used in the construction of tunnels in soft ground. On basis of the difficulties in the drilling of the horizontal boreholes in soft ground, the author analyzes on the three factors that may result in deflection of boreholes, expatiates on the borehole drilling technology for the piperoof reinforcement of shallowburied tunnels in soft ground and provides the methods for the measurement, prevention and correction of the inclinations of the horizontal boreholes. Taking the construction of the piperoof reinforcement of the ZhuGu running tunnel of Nanjing Metro as example, the author also presents the results of the cased auger boring of the horizontal boreholes.