综合勘察与分析法在某特大桥中的应用研究

Applied Research on the Comprehensive Survey and Analysis Method in a Bridge

研究目的:某特大桥位于构造缝合带,断裂发育、地震烈度高、地质条件极为复杂,岸坡稳定性、危岩、崩塌、落石等重大地质问题突出。“地”类勘察方法具有直观性强、精度高的特点,但受场区气候恶劣、海拔高、高差大、地势陡峭等因素影响,在某特大桥艰险地段实施难度大、安全风险高;两岸临江侧地形陡峭,无法开展地面勘察。针对桥址区环境特点及地质条件,需要引进新技术与地面手段相结合形成新型综合勘察与分析技术,以查明桥址区工程地质及水文地质条件,尤其是岸坡稳定性分析所需的岩体结构面、边坡卸荷带特征。研究结论:(1)采用“天空地”一体化的综合勘察方法解决了某特大桥现场众多勘察难题;(2)“天”类、“空”类、“地”类勘察成果吻合性好;(3)综合勘察与分析方法可以提高复杂地形、地质条件下的勘察精度和准确度;(4)综合勘察与分析方法在某特大桥中得到了应用与验证,可以在类似桥梁工程中推广应用。

Research purposes:A bridge is located in structural suture zone,with developed faults,high seismic intensity,extremely complex geological conditions.Therefore,major geological problems such as slope stability,dangerous rocks,collapses,and rockfalls are prominent.The"ground"survey method has the characteristics of strong intuition and high accuracy.However,due to the adverse climate,high altitude,large elevation difference,steep terrain and other factors in the site,it is difficult to implement and has high safety risk in the difficult sections of the bridge.According to the environmental characteristics and geological conditions,it is necessary to introduce new technologies and methods combined with ground means to form a comprehensive survey and analysis technology,so as to find out the engineering geological and hydrogeological characteristics,especially structural plane and unloading zone needed for the slope stability analysis.Research conclusions:(1)Many survey problems of the bridge site have been solved by using the integrated comprehensive survey method of the"air-space-ground".(2)The survey results of"air","space"and"ground"are in good agreement.(3)The comprehensive survey and analysis method can improve the survey precision and accuracy under complex terrain and geological conditions.(4)The comprehensive survey and analysis method have been well applied and verified in the bridge,and can be popularized and applied in similar bridge projects.