大直径螺旋钻机成孔优化研究

Analysis of the Optimization About Drilling by Large Diameter Spiral Drill

济南轨道交通R1线演马庄西站基坑围护桩施工采用1 100mm大直径长螺旋钻机引孔植桩,以此为背景对黄河厚冲积地层大直径螺旋钻机成孔进行了优化研究。提出输土效率系数Kd,并针对各地层不同输土机理计算其大小,经工程试桩验证后指导施工。螺旋钻机在黏土层中的输土效率为成孔时间的关键控制因素,根据黏土层中钻头挤压输土机理优化后,成孔时间比原钻机节约59.1%;根据松散土层中钻头挤压和土体与孔壁间摩擦共同作用输土机理优化后,比原钻机节约时间15.9%。

Yanmazhuang West subway station in Ji＇ nan rail transit line R1 using large diameter with 1 100mm and long spiral drilling machine piling precast pile for maintenance of foundation excavation. Based on this background, Large diameter spiral drill drilling in the Yellow River alluvial formation was optimized. The efficiency coefficient of drill named Kawas calculated with different mechanism in various strata, which could guide construction after validated by test pile. The efficiency coefficient of drill in the clay layer was the key control factor of pore forming time. The time was shortened by 59. 1% and 15.8% after optimized with different mechanisms.