岩溶地区厚覆盖层钻孔灌注桩溶洞处理技术.pdf

2013年3月上 施工技术 第42卷第5期 CONSTRUCTION TECHNOLOGY 75 D0I:10.7672//sgjs2013050075 岩溶地区厚覆盖层钻孔灌注桩溶洞处理技术* 戴祖生，陈庆华 (广东省长大公路工程有限公司，广东广州510620) [摘要]江肇西江特大桥主桥为(1283×210128)M4塔5跨单索面脊梁预应力混凝土矮塔斜拉桥.桥位处基 岩溶洞及溶蚀裂隙集中发育，覆盖层为厚17-37m的强透水性砂层.以西江特大桥南引桥钻孔灌注桩施工为背 景，对复杂地质条件地区桩基溶洞的处理技术进行了系统总结，重点介绍了溶洞注浆施工工艺以及特殊地段所采 用的桩周覆盖层旋喷帷幕压浆处理施工工艺，并对施工参数、成孔要点和旋喷施工要点进行了分析. [关键词]桥梁工程；斜拉桥；岩溶；钻孔灌注桩；溶洞；注浆；帷幕 [中图分类号]TU753.3;U445.551 [文献标识码]A[文章编号]1002-8498(2013)05-0075-03 The Treatment of Bored Pile Cave in Karst Region with Thick Overburden Dai Zusheng Chen Qinghua Guangdong Provincial Changda Highsay Engineering Co.Ltd.Guangzhou Guangdong 510620 China) Abstract:The Jiangzhao Xijiang River Bridge is a four-tower bridge with a total span of (1283 x210 128)m.It is a single cable plane cable-stayed bridge with prestressed concrete towers.The bridge is located in Karst region where the bed rock cave and corrosion fissure grows were found to be concentrated at the bridge site.The overburden is 17 ~37 meter thick sand layer with strong permeability.Based on the construction of the south approach span of the Xijiang River Bridge treatment of the bored pile cave in karst region with plicated geological conditions is well summarized.The construction technology of karst cave grouting and high pressure screw spray curtain at special sections are introduced in detail.Construction parameters main points of pore-forming and screw spray construction are also analyzed. Key words:bridges;cable stayed bridges;karst;bored piles;karst caves;grouting;curtains 岩溶、厚覆盖层等地质特点在我国南方地区分起于江门市杜阮镇（接江鹤高速公路），终于肇庆市 布较广.在该类型地质条件地区进行钻孔灌注桩 四会市东城区（接广贺高速公路）.大桥位于永安 基础施工常面临较高风险，事故频发. 镇与沙浦镇之间，桥位跨越西江主干流，主桥为 西江特大桥桥位处于广州三大断裂带和西江 (1283×210128)m4塔5跨单索面脊梁预应力 断裂带范围内，桥位地层岩性复杂多样，基岩溶洞 混凝土矮塔斜拉桥.桥跨立面布置如图1所示. 及溶蚀裂隙集中发育，溶洞及裂隙多且连通，覆盖 128 210×3 128 层为厚17~37m的强透水性砂层，岩面倾斜，岩体 强度高，地质条件非常复杂. 1工程概况 图1西江大桥立面示意（单位：m) 江门一肇庆高速公路是珠江三角洲经济区外 Fig.1 Elevation of Xijiang Bridge(unit:m) 环公路的西环段，位于珠江三角洲西部地区.路线 西江特大桥南引桥处表层覆盖层松散，其中粉 广东省交通科技项目：多塔长联大悬臂宽幅脊梁矮塔斜拉桥建设 (细)砂层深达30m左右，自稳性差...