分体井筒式地连墙锚碇基础承载性能研究
|
摘要
在借鉴国内外现有井筒式地连墙工程实践的基础上,结合清远西江特大桥的建设条件特点,提出了一种新型的分体井筒式地连墙锚碇基础结构形式。分体井筒式地连墙锚碇基础采用在顺桥向前后分体设置(净距12.3m)的矩形井筒地下连续墙基础,单个井筒平面尺寸为42m(横桥向)×18.6m(顺桥向),内外墙厚度均为1.2m,通过内部横纵隔墙分成8个隔舱,嵌入中风化岩层深度不小于3m。分析表明,前、后锚地连墙分担的竖向荷载比例为52%、48%,且以地连墙嵌岩段端阻力承担竖向荷载为主,外墙和土芯提供的竖向侧阻很小。前、后锚地连墙分担的主缆水平向分力分别为49.8%和50.2%,两者基本相等,均以土芯土抗力及外墙侧向土抗力分担为主。通过井筒式的构造及地连墙嵌入中风化岩层,能有效发挥井筒内土芯的抗水平力作用。提出了一种带结合钢板的榫槽式钢筋笼搭接锚固刚性接头,保证槽段间的刚性连接。相关成果可为悬索桥地连墙锚碇基础设计及研究人员提供参考。
Based on the existing engineering practice of bridge diaphragm wall at home and abroad and construction conditions of Xijiang Bridge in Qingyuan,a new type of bridge anchor foundation with split diaphragm wall is proposed.The split diaphragm wall is formed by two rectangular shaft diaphragm wall foundations which are installed front and back(clear distance 12 m)along the bridge.The plane dimension of a single diaphragm wall foundation is 42 m(transverse to the bridge)×18.6 m(along the bridge),which is divided into 8 compartments with wall thickness of 1.2 m.The depth of the embedded medium weathered rock is not less than 3 m.The analysis shows that the vertical load ratio between the front and back anchorage walls is 52%and 48%,mainly carried by end resistance of rock socketed section and rarely carried by lateral friction of outer and inner side wall.The lateral load ratio between the front and back anchorage walls is 49.8% and 50.2% respectively,mainly carried by lateral resistance of inner and outer wall in the rock section.The diaphragm wall shaft structure and embedded into the weathered rock can effectively exert the horizontal resistance of the soil core in the shaft.A rigid spliced joint with a steel plate cage with a steel plate is put forward to ensure the rigid connection between the segments.The related results can be used as reference for the design and researchers of the continuous wall anchor foundation of the suspension bridge.
Based on the existing engineering practice of bridge diaphragm wall at home and abroad and construction conditions of Xijiang Bridge in Qingyuan,a new type of bridge anchor foundation with split diaphragm wall is proposed.The split diaphragm wall is formed by two rectangular shaft diaphragm wall foundations which are installed front and back(clear distance 12 m)along the bridge.The plane dimension of a single diaphragm wall foundation is 42 m(transverse to the bridge)×18.6 m(along the bridge),which is divided into 8 compartments with wall thickness of 1.2 m.The depth of the embedded medium weathered rock is not less than 3 m.The analysis shows that the vertical load ratio between the front and back anchorage walls is 52%and 48%,mainly carried by end resistance of rock socketed section and rarely carried by lateral friction of outer and inner side wall.The lateral load ratio between the front and back anchorage walls is 49.8% and 50.2% respectively,mainly carried by lateral resistance of inner and outer wall in the rock section.The diaphragm wall shaft structure and embedded into the weathered rock can effectively exert the horizontal resistance of the soil core in the shaft.A rigid spliced joint with a steel plate cage with a steel plate is put forward to ensure the rigid connection between the segments.The related results can be used as reference for the design and researchers of the continuous wall anchor foundation of the suspension bridge.
引文
[1]彭运动,刘明虎,吴伟胜.地下连续墙在锚碇基础中的应用[C]∥中国公路学会桥梁和结构工程学会2001年桥梁学术讨论会论文集,2001.
[2]徐国平,李健清.圆形地下连续墙在悬索桥锚碇基础中的应用[J].公路,2004,(11).
[3]马进.地连墙在悬索桥锚碇基础中的应用[C]∥中国公路学会桥梁和结构工程学会2003年全国桥梁学术会议论文集,2003.
[4]刘明虎,付宇文.井筒式地下连续墙基础设计及应用[J].公路,2006,(5):52-55.
[5]吴九江,程谦恭,文华.地下连续墙基础在日本的多样化发展[J].工业建筑,2013,43(1):144-147.
[6]程谦恭,文华,宋章.矩形闭合墙桥梁基础研究现状及发展趋势[J].建筑技术,2009,40(3).
[2]徐国平,李健清.圆形地下连续墙在悬索桥锚碇基础中的应用[J].公路,2004,(11).
[3]马进.地连墙在悬索桥锚碇基础中的应用[C]∥中国公路学会桥梁和结构工程学会2003年全国桥梁学术会议论文集,2003.
[4]刘明虎,付宇文.井筒式地下连续墙基础设计及应用[J].公路,2006,(5):52-55.
[5]吴九江,程谦恭,文华.地下连续墙基础在日本的多样化发展[J].工业建筑,2013,43(1):144-147.
[6]程谦恭,文华,宋章.矩形闭合墙桥梁基础研究现状及发展趋势[J].建筑技术,2009,40(3).