近岸水上钻孔灌注桩施工控制技术研究

Construction Control Methods of Bored Concrete Piles in Waters

由于昆明环湖南路古城段提升改造工程古城2号特大桥桩基础施工时,地质条件复杂,钻孔施工过程中易塌孔、缩孔,孔底沉渣清除困难,而且单桩混凝土灌注量大,极易发生断桩的工程问题。针对现场工程地质条件和施工技术,对存在的技术难点采取了针对性的控制措施。通过超声波和静载加压检测桩身工程质量,证明桩基工程质量良好。因此,所采取的技术措施提高了桩基础施工质量,缩短了施工工期,对类似工程具有借鉴意义。

This paper presents a case history of bored reinforced concrete pile installation for a long bridge at the Historical City Upgrade Project near Kunming Lake Road South.The site has complicated geological and geotechnical conditions,construction difficulties were encountered during the bored pile installation.These difficulties were and necking of the boreholes and loose debris accumulated at the bottom of boreholes.Due to the size of these bored piles and a large quantity of concrete pouring is required,the integrity of the bore concrete piles was often compromised.The paper introduces the construction quality control measures that could minimizing these defects.These measures include ultrasonic integrity testing plus static loading test were applied on the selected piles.The test results indicate that the quality control measures were successful.