大跨越基础复杂地质钻孔灌注桩成孔机械选用及质量控制

Selection and Quality Control of Drilling Machine for Large Span Foundation Complex Geological Bored Pile

【目的】对±800 kV白浙线长江大跨越工程复杂地质下的桩基施工难题进行分析,并提出解决方案,为今后同类型工程施工提供建议。【方法】本研究从优化施工机械选用、细化施工方法、合理运用长护筒、采用新型制浆材料等方面入手,充分发挥旋挖钻机对包含流沙的复杂地质适应性好、对深层岩石掘进效率高等显著优势,同时辅以北斗导航桩基信息化系统及超声波成孔检测装置等技术手段。【结果】在采取有效措施优化施工方案后,大跨越桩基施工效率及成孔质量均得到显著提高。【结论】经工程实际验证,优化施工方法后的旋挖钻机在复杂地质桩基施工中全部实现预期目标。

[Purposes]To analyze the difficulties and solutions of pile foundation construction under com⁃plicated geology of±800 kV Baizhe Line Yangtze River span project,and to provide suggestions for the construction of similar projects in the future.[Methods]Starting from optimizing the selection of con⁃struction machinery,refining construction methods,rational use of long guard drum,adopting new pulp⁃ing materials,etc.,the rotary drilling rig has the significant advantages of better adaptability to complex geology including quicksand and higher efficiency for deep rock excavation compared with traditional cir⁃culating drilling rig.At the same time,Beidou navigation pile foundation information system and ultra⁃sonic hole detection device and other technical means are adopted.[Findings]After taking effective mea⁃sures to optimize the construction scheme,the construction efficiency and pore-forming quality of largespan pile foundation are significantly improved.[Conclusions]Through the actual engineering verifica⁃tion,the rotary drilling rig with optimized construction method has achieved all the expected objectives in complex geological pile foundation construction.