(1. Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan,Hubei 430010,China;2. Hunan Provincial Communications Planning,Survey and Design Institute,Changsha,Hunan 410008,China;3. Hunan Jishou—Chadong Highway Construction and Development Co.,Ltd.,Jishou,Hunan 416000,China)
Abstract:Due to both the distance between constructions and the distance between construction and high-steep slope are quite small,grasping the stability of foundation rock and mutual effects between constructions accurately is crucial to the feasibility of design scheme. Four key problems concerning stability of foundation rock of Aizhai suspension bridge are summarized. Comprehensive approaches to investigate the bridge foundation rock masses are introduced,as well as main geological defects,the stability analysis and monitoring results of foundation rock masses during construction stage. The geological conditions exposed during excavation,stability analysis and monitoring results show that comprehensive survey approaches are indispensable to fully understand the geological conditions of rock masses. The stability problems of Aizhai suspension bridge focus on the high-steep slopes of two banks. Design load never causes significant deformations;and mutual effects between constructions are not obvious. The stability of rock foundations can be guaranteed if the high-steep slopes are reinforced appropriately. The tower-beam-separation design and the arrangement of constructions are feasible. The studies of foundation rock stability give support to the innovation in structural design. Tunnel-type anchorage can generate very huge pull-resistance capability caused by gripping effect from surrounding rock masses. Because the tunnel-type anchorages used in large suspension bridges at home and abroad are limited,and the researches on rock mechanics problems of surrounding rock masses of tunnel-type anchorage are not deep enough,the bearing capacity of tunnel-type anchorage may be seriously underestimated.
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