徐工XR580HD、XR400E旋挖钻机在硬质泥岩超长桩基中的应用

Application of XCMG XR580HD and XR400E Rotary Drilling Rigs in Super-long Pile Foundation of Hard Mudstone

G244线庆阳过境段公路工程火巷沟特大桥16号主墩桩基工程的墩位出露地层为第四系风积黄土夹古土壤,下伏白垩系泥岩,桩身上部黄土地质中粉质黏土层极易塌孔,加之下部泥岩层抗压强度大,具有桩基数量多、桩长深、孔径大、地质复杂,成孔难度大、施工工期紧等难点。文章根据技术分析,选用了徐工XR580HD、XR400E旋挖钻机进行成孔,取得了良好效果。在此基础上,总结了前述不利条件下的大直径超长桩基主要施工技术,旨在为今后黄土地区超长桩基底部泥岩层旋挖成孔施工提供参考。

The exposed stratum of No.16 main pier pile foundation project of Huoxianggou Bridge in Qingyang transit section of G244 line is Quaternary aeolian loess with ancient soil,underlying Cretaceous mudstone.The silty clay layer in the loess geology of the upper part of the pile body is easy to collapse.In addition,the compressive strength of the lower mudstone layer is large,which has many dificulties such as large number of pile foundations,deep pile length,large pore size,complex geology,difficult hole forming and tight construction period.According to the technical analysis,Xugong XR580 HD and XR400 E rotary drilling rigs were selected for hole forming,and good results were achieved.On this basis,the main construction technologies of large-diameter super-long pile foundation under the above adverse conditions are summarized,aiming to provide reference for the rotary drilling hole construction of the mudstone layer at the bottom of super-long pile foundation in loess area in the future.