上海地区特深圆形竖井开挖承压水控制技术及效果  

Technology and effects of confined water control of extra deep circular shaft excavation in Shanghai region

作　　者：刘树佳 LIU Shujia(Shanghai Chengtou Water Group Co.,Ltd.,Shanghai 201103,China)

机构地区：[1]上海城投水务(集团)有限公司,上海201103

出　　处：《水资源与水工程学报》2023年第1期127-134,共8页Journal of Water Resources and Water Engineering

基　　金：国家973计划项目(2015CB057806);国家自然科学基金项目(52090082)。

摘　　要：苏州河段深层排水调蓄工程云岭综合设施和苗圃综合设施竖井基坑施工首次要求对上海地区第三层承压含水层水位进行控制。结合云岭综合设施特深圆形竖井开挖承压水控制工程实例,在分析承压含水层的分布特点和工程采取的降水措施的基础上,以工程实测数据为基础,分析软土地区深层承压水控制工艺和控制效果。结果表明:工程采取的竖井地墙和外侧防渗墙两层隔水措施,首次实现了上海地区第三层承压水降水,最大水位降深达到57.8 m,保证了基坑的稳定性。实测数据显示防渗墙外的水位降深小于防渗墙与围护结构之间的水位降深,水位降深速率具有相同的规律;各土层孔隙水压力变化与承压水降水相对应,承压水水位开始恢复后,迎土面深层孔隙水压力明显增大,且深度越深,孔隙水压力增大的趋势越明显,迎坑面水压力变化则较为平缓。所得结论可为今后上海地区类似工程施工和深层地下空间开发提供参考。The extra deep circular shaft excavation of Yunling and Miaopu comprehensive facility of the drainage and regulation project in the Suzhou River section requires to control the water level of the third confined aquifer in Shanghai for the first time.Based on the analysis of the distribution characteristics of the confined aquifer and the dewatering measures taken by Yunling comprehensive ficility,the control technology and effects of deep confined water in soft soil area are analyzed based on the measured data.The results show that the two-layer water isolation measures of shaft ground wall and outer cut-off wall adopted by the project accomplished the dewatering of the third layer confined water in Shanghai region for the first time,and the maximum water level drop reached 57.8 m,which ensured the stability of the foundation pit.The measured data show that the water level drop outside the cut-off wall was smaller than that between the cut-off wall and the retaining structure,so was the water level drop rate.The change of pore water pressure in each soil layer corresponded to the dewatering of the confined water.After the restoration of the confined water level,the deep pore water pressure on the soil facing surface increased significantly,and the deeper the depth,the more obvious the increasing trend of the pore water pressure;however,the change of water pressure on the pit facing surface was relatively gentle.The conclusions can provide some reference for the construction of similar projects and the development of deep underground space in Shanghai region in the future.

关 键 词：特深圆形竖井 承压水控制 第三层承压水 现场实测 孔隙水压 上海地区 

分 类 号：TV223.5[水利工程—水工结构工程] TU473[建筑科学—结构工程]