大直径深水钻孔灌注桩施工质量控制措施及研究

Construction Quality Control Measures of Large Diameter Deep Water Bored Pile

地处深水环境中的南沙港铁路西江特大桥156#、157#塔墩基础采用大直径钻孔灌注桩,钻孔深度达到107 m,桩基施工难度大、质量标准要求高、风险高。为防范超深大直径桩基施工过程中塌孔、断桩、沉渣厚度超标、强度不足等质量风险事故,通过采用分级扩孔钻进套打技术,气举法清孔,配置性能优良的混凝土,严格控制导管埋深;管理上实行责任承包制度大大增强了施工人员的责任心,保证了桩基成桩质量。通过超声波成桩检测结果,充分证明了在淤泥质深水环境下大直径桩基施工质量控制措施是很成功的,并为今后同类桩基的施工提供一些借鉴和参考。

Large diameter bored piles are adopted in the 156# and 157# pier foundations of Xijiang Super Large Bridge under the deep water environment of Nansha port railway, and the drilling depth reaches 107 m. The construction of the pile foundation is full of difficulties, high quality standard and high risks. In order to prevent the quality risk accidents such as collapse hole, broken pile, excess slag thickness and insufficient strength in the construction process of super deep and large diameter pile foundation, the quality of pile foundation is guaranteed by the management of responsibility system through the use of grading and drilling technique, gas lifting method on clearing hole, configuring excellent concrete and strictly controlling the buried depth of the pipe. Based on the test results of ultrasonic wave, it is proved that the construction quality control measures of large diameter pile foundation in the silt deep water environment are very successful, and provide some reference for the construction of similar pile foundation in the future.