张晓涛

摘 要：洛阳地铁一号线某车站在深基坑开挖过程中发现地下水位远高于设计阶段勘察地下水位，地处洛河Ⅰ级台地，地层为砂卵石地层。降水管井施工困难，缩颈、塌孔现象严重，结合现场地质状况，分析各类成孔钻机特点，优化降水井成井工艺，选用长螺旋钻机压灌泥浆护壁成孔，成功解决富水卵石地层成井措辞塌孔、缩颈等问题，且具有成井效率高、施工质量可控、施工成本较低等优点，长螺旋钻机成井工艺的成功应用为类似地质情况下基坑降水施工提供借鉴。

关键词：富水砂卵石;深基坑;降水井;长螺旋钻机;泥浆护壁

中图分类号：TU753.3     文献标识码：A     文章編号：1003-5168（2021）36-0059-04

Study on Dewatering Technology of Deep Foundation Pit in Water Rich Sandy Cobble Stratum

ZHANG Xiaotao

（Sinohydro  Bureau11 Co.，Ltd，Zhengzhou Henan 450001）

Abstract：The underground water level of a station of Luoyang Metro Line 1 during deep foundation pit excavation is much higher than that of the survey in the design stage.It is located in the class I platform of Luohe River，and the stratum is sandy pebble stratum.The construction of dewatering pipe well is difficult，necking and hole collapse are serious.Combined with the geological conditions of the site，the characteristics of various drilling rigs are analyzed，the well completion technology of dewatering well is optimized，and the long screw drilling rig is selected to fill mud to protect the wall for hole formation，which successfully solves the problems of hole collapse and necking in water rich pebble formation，and has the advantages of high well completion efficiency，controllable construction quality and low construction cost the successful application of rotary drilling well technology provides reference for foundation pit dewatering construction under similar geological conditions.

Keywords：sandy cobble stratum;deep foundation pit;dewatering well;long screw drill slurry wall protection

随着越来越多深、大基坑的出现，我国对于深基坑工程技术的研究也逐渐深入。在进行深基坑开挖时，不可避免遇到地下水位较高的情况，为了防止地下水带来的涌砂、地面变形、边坡失稳、地基承载力降低等情况的出现，对地下水的处理尤为重要。基坑的开挖深度越大，地下水对施工的危害性就越大，地下水处理成功与否直接影响整个工程的进度，其中地下水是影响深基坑安全的重要因素之一，尤其是在地质条件较为复杂的地区，必须要对地下水进行妥善处理，有效地减小地下水对深基坑的影响，以保证工程的可靠性与经济性。

洛阳地铁1号线塔湾站施工场地的地势平坦，所处地貌为洛河Ⅰ级阶地，位于洛河古河道范围内。根据勘察报告，在塔湾站勘探深度内……