中化泉州码头大直径灌注桩施工质量控制技术

中化泉州码头采用直径为2.2 m和2.6 m的灌注桩作为基桩,由于大直径灌注桩在水运工程中比较少见,其清渣、混凝土浇筑等施工中的质量控制比较复杂,在施工前期产生了桩底盆形沉渣和桩间夹渣的异常情况。通过现场分析,清孔后泥浆中含砂率的大小直接影响着沉渣厚度。总结水运工程中常规灌注桩施工质量控制技术,提出更严格标准以满足大直径灌注桩施工质量要求。在施工中采用气举反循环并结合泥浆净化装置进行清渣,与传统正循环清孔相比,其质量和效率得到了显著改善。该套设备可使泥浆中的含砂率由常规要求的4%~6%有效降低至2%以下有效,灌注桩桩身完整性得到了进一步保证,施工质量很好地满足了规范要求。

Quality control technology of large-diameter bored pile for Sinochem Quanzhou port

In the Sinochem Quanzhou docks with diameter of 2.2 m and 2.6 m bored pile as the foundation, since the large-diameter bored pile in port & waterway engineering is relatively rare, the quality control of slag cleaning and concrete construction is more complex, and abnormal circumstances of basin-shaped sediment and local middle sediment occur in the early construction. The on-site analysis shows that the sand rate of the mud after slag cleaning influences directly the sediment thickness. This paper summarizes the conventional quality control technology of bored pile construction in the port & waterway engineering and puts forward more strict standards to meet the requirements of large-diameter bored pile construction quality. Adopting air lift reverse circulation combined with mud purification device, we improve significantly the quality and efficiency of slag cleaning. The device effectively reduces the sand rate of the mud from the conventional 4% ~ 6% down to less than 2%, and the bored pile integrity is further assured, so the construction quality meets the requirements of specification.