芜湖跨座式单轨岩土工程综合勘察技术应用

Application of Comprehensive Survey Technology in Wuhu Straddle Monorail Geotechnical Engineering

芜湖跨座式单轨1号线、2号线分别沿南北、东西向贯穿芜湖主城区,城市勘察环境与岩土条件复杂;芜湖高架站多采用“桥建合一”独柱大悬臂结构,区间多采用连续钢构轨道梁桥,结构形式具特殊性;跨座式单轨作为轨道交通一种特殊制式,目前现行勘察规范尚无针对性的描述与技术要求,以上均给勘察工作提出了更高的要求。针对岩溶问题,采用地面电法、地质雷达(单孔雷达、跨孔雷达CT)与钻探结合的岩溶勘察方法;针对软土问题,采用扁铲侧胀、十字板剪切、静力触探等原位测试与室内试验相结合的方法;针对水文地质问题,采用水文调查、“一抽三观”水文试验、长期水文观测及室内试验相结合的方法。研究表明,采用综合勘察技术可充分查明岩溶分布及发育特征、软土特性及力学性质差异,准确确定水文地质参数,合理优化抗浮设计。

Wuhu Straddle-type Monorail Line 1 and Line 2 run through the main urban area of Wuhu along the north-south and east-west directions respectively,and the urban investigation environment and geotechnical conditions are complicated.In Wuhu viaduct station,the single-column large cantilever structure concept of“bridge construction in one”is used,and the continuous steel track beam bridge is used in the section,which has its special structural form.As a special standard of rail transit,straddle monorail has no specific description and technical requirements in the current survey standards,which requires higher requirements for the survey work.To solve the karst problem,the karst exploration methods were combined with ground electric method,geological radar(single hole radar,cross hole radar CT)and drilling.To solve the problem of soft soil,the methods of in situ test and laboratory test,such as lateral expansion of flat shovel,cross plate shear and static penetration were used.To solve the hydrogeological problems,the methods of hydrology investigation with“one drawing and three observations”hydrology experiment,long-term hydrology observation and laboratory experiment were adopted.The research shows that the comprehensive survey technology can fully identify the karst distribution and development characteristics,soft soil characteristics and mechanical property differences,accurately determine the hydrogeological parameters,and rationally optimize the anti-floating design.