以贵州省内某一深切峡谷桥梁为例,阐述桥梁勘察设计遇特殊地质情况时的勘察手段.研究表明,川东、黔北奥伦阶地层,即嘉陵江组和茅草铺组为上杨子台地上同一时期沉积地层,成岩环境具有很大程度的相似性,均在顶部存在岩溶角砾岩,其岩性特征亦相似.经过工程实例分析,岩溶角砾岩存在的区域由于其众多不良特性,易伴生其他不良地质.通过对该地质现象的研究分析,为桥梁顺利建设提供了参考资料,为其他类似的工程建设提供借鉴经验.
Taking a deep canyon bridge in Guizhou province as the example,the survey methods used in bridge survey and design when encountering special geological conditions are elaborated.The research shows that,the Orlan terrace strata in eastern Sichuan and northern Guizhou,namely the Jialingjiang formation and Maocaopu formation are sedimentary strata of the same period on the ground of Shangyangzitai.The diagenetic environment is highly similar,with karst breccia at the top and similar lithological characteristics.Through the engineering case analysis,it has been found that the areas with karst breccia are prone to other unfavorable geological conditions due to their numerous unfavorable characteristics.Through the research and analysis of this geological phenomenon,the reference materials are provided for the smooth construction of bridges,so as to provide reference experience for other similar engineering constructions.