长输管道定向钻穿越断点段补救施工

Remedial Construction on Break-off at Directional Drilling Crossing of Long Distance Transmission Pipeline

西气东输管道工程在郑州黄河北岸滩地设计三次定向钻穿越,在第二次穿越管道回拖过程中,钻具脱落,致使穿越施工无法继续进行。文章针对这一穿越工程事故,详细介绍了补救施工方法及其关键技术。根据工程的实际情况,采取大开挖方式将断点处管段返到变更后的设计高程,再采用沟埋敷设法完成剩余管道的穿越。通过采取分层取土、多级多型降水和钢板桩支护等一系列措施,实现了黄河滩地地表以下19m深处管道的成功对接。

Aimed at the accident of drilling tool break-off happened at directional drilling crossing through north bank of Yellow River in Zhengzhou in West to East Gas Pipeline Project, the remedial construction method and other related key techniques are introduced in detail. According to the practical situation, the large excavation method was used to shift the break-off pipe crossing segment to the altered design altitude, than the buried trench laying method was applied to accomplish remained pipeline crossing. After a series of measures, such as taking soil out layer by layer, lowering water level with types of multi-layer approaches and shoring with steel sheet piles, were adopted, the connection between the pipe at the depth of 19m and the ground pipe was successfully realized.