摘要
《建筑桩基技术规范》(JGJ94-2008)中规定,持力层起伏较大、地层分布复杂时,应根据具体工程条件适当加密勘探点,但未对桩基具体施工方法进行阐述。沿海孤石多发地区采用预应力管桩施工易产生沉桩困难、桩身断裂等问题,采用旋挖灌注桩施工又存在成本较高的劣势,相比之下,旋挖植桩具有能穿越地底孤石、易于沉桩、较为经济等特点,是这一矛盾的有效解决方案。旋挖植桩预先利用旋挖钻机成孔,穿越地底孤石等障碍物,成孔后向孔内注入水下细石混凝土,最后再利用柴油锤机植入预应力管桩。以厦门白鹭体育场项目为载体,简要介绍了锤击管桩和旋挖植桩两种施工方法及操作要点,提出了旋挖植桩混凝土换填计算公式;并结合《建筑桩基技术规范》(JGJ94-2008)单桩竖向极限承载力标准值计算公式及现场试桩试验数据对两种施工方法进行对比分析,说明旋挖植桩的优势,并建议桩基设计时应因地制宜,适当加强试桩工作,以保证桩基方案的合理可行性。
According to China’s Technical code for building pile foundations(JGJ94-2008), exploration points should be properly encrypted according to specific engineering conditions when bearing strata are undulating and strata distribution is complex, but specific construction methods of pile foundations are not described. In coastal solitary rock areas,prestressed pipe pile construction is easy to cause problems such as difficult pile sinking and pile body fracture, while rotating excavation pile construction has the disadvantage of high cost. By contrast, implanted pile has the characteristics of being able to pass through underground solitary rock, easy pile sinking and relatively economic, which is an effective solution to this contradiction. Implanted pile using rotating drill into a hole in advance through the underground obstacles such as boulder, hole to hole after injection of fine stone concrete underwater, finally using diesel hammer machine embedded prestressed pipe pile. Taking Xiamen Egret Stadium project as the carrier, this paper briefly introduces two construction methods and operation points of hammer pipe pile and implanted pile, and puts forward the calculation formula of concrete replacement of implanted pile. Combined with the standard calculation formula of vertical ultimate bearing capacity of single pile in Technical code for building pile foundation(JGJ94-2008) and field test pile test data,the two construction methods are compared and analyzed to illustrate the advantages of implanted pile implantation, and it is suggested that pile design should be based on local conditions and test pile work should be appropriately strengthened to ensure the reasonable feasibility of pile foundation scheme.
作者
万鸿志
朱茂茂
黄青隆
WAN Hongzhi;ZHU Maomao;HUANG Qinglong(Xiamen Jiyehengxin Consulting Co.,Ltd.,Xiamen 361006,China;China Construction Eighth Engineering Division,Co.,Ltd.,Shanghai 200122,China)
出处
《建筑结构》
CSCD
北大核心
2022年第S02期2927-2932,共6页
Building Structure
关键词
孤石多发地区
预应力管桩施工
旋挖植桩
桩基设计
boulder-prone area
prestressed pipe pile construction
implanted pile
pile foundation design
