地面预注浆钻孔结构的优化设计

The Optimization Design of Surface Pre-grouting Drilling Role Structure

地面预注浆技术的应用范围已由立井井筒,扩展到了巷道、硐室、煤矿工作面等,钻孔结构的设计也需要打破传统的立井井筒地面预注浆钻孔结构的设计思路,在保证孔内安全和技术可行的基础上降低施工成本。针对大贾庄铁矿溜破系统地面预注浆工程的钻孔结构,根据拟建区域地质条件的特点,通过甩管工艺和非注浆层位裸孔段的特殊结构,进行了多方案设计;并通过多项技术经济指标对钻孔结构的4个设计方案进行了比较分析,分别确定了在工程前后2个施工阶段适宜选择的最优钻孔结构设计方案,即一序孔的方案是190 m深度以上采用套管支护,下部为裸孔段设计;二序孔的方案是190 m深度以上采用套管支护,在注浆起始深度的上部甩下约20 m套管,2种套管之间设计为裸孔段。

The application of surface pre-grouting technique has been expanded from vertical shaft to roadway,chamber,mining face etc. The design of hole structure should break through the traditional thinking pattern of surface pre-grouting in vertical shaft,and also reduce construction cost on the premise of safety and technical feasibility. In view of the drilling structure in surface pre-grouting engineering of ore-pass fragmenting system in Dajiazhuang Iron Mine,according to the characteristics of the geological conditions in the definite area,and based on the pipe whipping process and the special structure of no-shoring segment in no-grouting rock strata,the multi-scheme design was proposed. Four kinds of designing scheme were contrasted and analyzed by the technical and economic index to select the optimal schemes of hole structure before and after construction. The upper part（Depth〈190 m）of holes in first sequence was supported by casing,and the lower part was designed as no-shoring segment. The upper part（Depth〈190 m）of holes in second sequence was supported by casing,and about 20 m casing pipe was whipped above the original depth of grouting,and the middle part was designed as no-shoring segment.