刘家峡大桥桥台岸坡岩体特性及其稳定性研究

刘家峡大桥位于刘家峡水库右岸冲沟沟口,是临夏折桥至兰州市达川二级公路的控制性重点工程.该桥设计采用单跨悬索桥方案（跨径20 m＋536m＋20m）,建成后将成为甘肃省乃至北方地区最大跨度的桥梁.通过地质调绘、工程钻探、平硐勘探、岩体声波测试、大型原位岩体变形试验和室内力学试验多种方法,对桥台岸坡岩体特性进行了详细研究.基于变形理论,运用Geo-Studio和FLAC数值模拟软件对库水位升降、桥基开挖、桥塔荷载等因素影响下的桥台岸坡的稳定性进行了研究,最后并就桥台岸坡防治措施提出了建议.

Study on the Characteristics of Rock Mass and Stability of the Liujiaxia Bridge Abutment at Reservoir Bank

The Liujiaxia Bridge is located at the right gully of the Liujiaxia Reservoir,which is the control engineering of the highway from Zheqiao town to Lanzhou city.It is single span suspension bridge project （20 m ＋ 536 m ＋ 20 m）.After built,it will be the largest span bridge in Gansu province and northern regions.Through a variety of methods,including the geological mapping,engineering drilling,adit prospecting,acoustic measurement of rock mass,large rock deformation test in situ and laboratory experiment,the characteristics of rock mass in the bank slop of reservoir is detailed analyzed in this paper.Based on the theory of strength and deformation theory,using Geo-Studio and FLAC numerical simulation software,the stability of the abutment slope under the influence of factors such as the rising and drawdown of reservoir water level,foundation excavation,tower load is studied.Lastly,the bridge abutment prevention measures were proposed.