【摘要】 浙江省舟山西堠门大桥为一主跨跨度为1 650 m的悬索桥,其主塔高度约200 m,且位于海中的孤岛上。桥基所在地层为晚侏罗系流纹斑岩,山体顶部有少量坡残积层,地形上该山体平均长200 m、宽80 m,四面临空,且受数条小断层及其他构造裂隙的影响,山体岩体完整性较差。显然考虑大跨度和高塔柱的联合作用,尤其是台风的叠加作用下,桥基边坡稳定性是该大桥方案能否成立的关键。结合桥基设计位置,在考虑工程荷载作用下,未来边坡最易发生失稳的部位应是南侧边坡,其余地段发生较大规模失稳的可能性小。通过现场地质调查,在查明控制桥基南侧边坡稳定的控制性边界条件基础上,通过多种计算方法,系统分析受上部结构荷载尤其是风荷载等综合作用下的工程边坡稳定性。更多还原

【Abstract】 The main span of Xihoumen Suspension Bridge is 1 650 m,and its main tower(bridge foundation) with height above 200 m lies on an island in the sea.Stratum near the bridge foundation is rhyolite porphyry in late Jurassic period.A little of slope eluvium exists on the top of the mountain,which is 200 m long and 80 m wide,and its all sides face to sea.The integrality of rock mass of the mountain is relatively poor because of the effect of some faults and other structural fissures.Obviously,the stability of the bridge foundation slope considering the united effect of large span and high tower,especially the repeated additional effect of typhoon,is a key problem related that whether the bridge project is tenable.Combining the design place of the bridge foundation,considering engineering load effect,it is found that the position where destabilization will happen most easily is the south slope;and the possibility that the large-scale destabilization happens in other positions of the slope is small.Based on the field geological survey,the boundary conditions controlling the stability of south slope are found.Systematic analysis of the slope stability is conducted under the integrated effects of top structure loads,especially the wind load through many methods.更多还原