杭州八堡泵站工程软岩地基嵌岩桩入岩判定的研究与实践  

Research and Practice on the Determination of Rock-Socketed Pile in Soft Rock Foundation of Hangzhou Babao Pumping Station Project

作　　者：刘倩 李健民 许明显 LIU Qian;LI Jianmin;XU Mingxian(Zhejiang Design Institute of Water Conservancy&Hydro-electric Power Co.,Ltd.,Hangzhou 310002,China)

机构地区：[1]浙江省水利水电勘测设计院有限责任公司,浙江杭州310002

出　　处：《中国水能及电气化》2022年第8期20-23,40,共5页China Water Power & Electrification

摘　　要：杭州八堡泵站工程主泵房采用旋挖钻孔成桩,下伏泥质粉砂岩为软岩,由于风化深、风化界限起伏较大、遇水易软化等特点,在入岩判定中存在多次判岩、判岩时间较长等问题。文章对旋挖机参数、沉渣、原位测试进行了综合比选试验,结果表明采用旋挖机钻杆钻速与给进力进行初判、捞渣筒打捞钻渣进行终判、钻孔波速测试进行检验桩端入岩层位的综合方法能提高嵌岩桩入岩判定的效率,使每根桩平均入岩判定时间由48.2min压缩至34.2min,为杭嘉湖地区相似地质条件的工程提供了宝贵的经验。The main pump room of Hangzhou Babao Pumping Station adopts rotary drilling to form piles,and the underlying argillaceous siltstone is soft rock.Because of the characteristics of deep weathering,large fluctuation of weathering boundary and easy softening when meeting with water,there are many problems in rock entry judgment,such as multiple rock judgmentand long rock judgment time.In this paper,the comprehensive comparison and selection test of parameters,sediment and in-situ test of rotary excavator is carried out.The results show that the comprehensive method of preliminarily judging drilling speed and feed force of rotary excavator drill pipe,finally judging drilling slag by slag-fishing barrel,and testing drilling wave velocity can improve the efficiency of rock-socketed pile’s rock-entry judgment,and reduce the average rock-entry judgment time of each pile from 48.2min to 34.2min,which provides valuable reference results for similar geological conditions in Hangjiahu area.

关 键 词：软岩 嵌岩桩 入岩判定 旋挖钻孔 

分 类 号：TV437.1[水利工程—水工结构工程]