Curtain grouting design for Zhongguan iron mine demands big depth and high verticality,but under the complex geological and hydrological conditions,borehole deviation is serious.

• 中关铁矿帷幕灌浆孔设计深度深、钻孔垂直度要求高,加之地质条件、水文条件的特殊性和复杂性,钻孔偏斜超标严重,经过实践,摸索出一套有效的防斜、纠斜技术措施。