大直径灌注桩深长护筒多功能钻机接驳埋设技术

针对深厚松散填土、淤泥质土、粗砂等地层大直径灌注桩施工过程中深长护筒的埋设，提出一种高效安全的多功能钻机埋设方法。在施工过程中先采用旋挖钻机引孔，然后采用特制接驳器将钻机动力头与长护筒顶端相连接，多功能钻机利用超强扭矩回转底部带合金刀头的护筒并对地层进行切削，同时将护筒下压至预定深度。该技术有效提高了大直径深长护筒的埋设效率，确保了护筒的安放垂直度，对周边地层影响小，为大直径深长护筒安放提供了一种新的工艺方法。

Connection and Burying Technology for Deep and Long Casing of Large Diameter Cast-in-place Pile with Multi-function Drilling Machine

Aiming at the burying of deep and long pile casings during the construction of large-diameter cast-in-place piles in deep and loose fill, muddy soil and coarse sand, an efficient and safe embedding method with multi-functional drilling rig is proposed. In this process, a rotary drilling rig is used to guide the hole, and then a special adapter is used to connect the power head of the drill with the top of the long casing. The multi-functional drill uses super torque to rotate the casing with alloy cutter head at the bottom and cut the formation, and at the same time, the casing is pressed down to a predetermined depth. The technology effectively can improve the embedding efficiency of large-diameter deep and long pile casings, ensures the verticality of the pile casings, and has little impact on the surrounding strata,and it is a new technological method for the placement of large-diameter deep and long pile casings.