N-JET工法在大粒径砂卵石地层止水中的应用

Application of N-JET Method in Water Stoppage of Large Particle Size Sand and Gravel Stratum

N-JET工法是在浆液压力的作用下,通过钻管(杆)连接特殊喷浆装置(钻头)全方位旋转或角度旋转、向上提升、变换提升等方法结合多喷嘴多角度切削土体,将切削的土体与浆液混合搅拌,待浆液凝固后,在土中形成一个固结体,可以提高土层的强度参数,减小土体的渗透系数,从而达到地层加固和注浆止水的目的。该技术在日本应用广泛,具备良好的止水效果,但是在国内应用较少。本文结合工程实例,重点论述N-JET工法在大粒径砂卵石地层止水中的应用。

The N-JET method is a combination of multi-nozzle and multi-angle cutting of the soil by a drill pipe(rod)connected to a special spray device(drill)under the action of slurry pressure by means of omnidirectional rotation or angular rotation,upward lifting,transformation and lifting.The soil and the slurry are mixed and stirred.After the slurry is solidified,a solid body is formed in the soil,which can improve the strength parameters of the soil layer and reduce the permeability coefficient of the soil,thereby achieving the purpose of stratum reinforcement and grouting.This technology is widely used in Japan and has a good water stop effect,but it is rarely used in China.In this paper,combined with engineering examples,the application of N-JET method in water stoppage of large-size sand and gravel stratum is emphasized.