雨水泵站基坑复合型支护体系的施工控制

Construction Control of Composite Support System for Foundation Pit of Rainwater Pumping Station

为探析雨水泵站基坑复合型支护体系的施工控制,以天津市东丽区金钟街片区14#雨水泵站工程为对象,立足雨水泵站基坑支护的重难点,分析复合型支护体系的施工控制要点。实践表明:雨水泵站基坑较深,支撑难度大,尤其是基底位于淤泥质粉质黏土层,开挖难度大,单一的支护技术难以实现对深基坑的有效支护。为提升基坑支护效果,采用复合型支护体系。首先,通过钻孔灌注桩Φ1000 mm,间距为1200 mm进行基底加固,在外侧设Φ850 mm,间距为600 mm的三轴搅拌桩止水帷幕,以降低地下水对支护体系造成的影响,内支撑体系为420 mm×420 mm的格构柱结构;其次,在施工中加强基坑支护监测控制,按照监测结果及时调整施工参数,更好地保障泵站基坑的稳定性,促使雨水泵站施工任务顺利完成。

In order to analyze the construction control of the composite support system for the foundation pit of the rainwater pumping station,based on the No.14 Rainwater Pumping Station Project in Jinzhong Street District of Dongli District in Tianjin,the construction control points of the composite support system were analyzed based on the important and difficult points of the foundation pit supporting for the rainwater pumping station.The practice shows that the foundation pit of the rainwater pumping station is deep and difficult to support,especially when the foundation is located in the silty clay layer,the excavation is difficult.The single support technology is difficult to realize the effective support for the deep foundation pit.In order to improve the supporting effect of foundation pit,the composite support system is adopted.First,the foundation is strengthened by the bored pile with a spacing of Φ1000 mm and 1200 mm,and the water curtain of the three-axis mixing pile with a spacing of Φ850 mm and 600 mm is set on the outside to reduce the influence of groundwater on the support system.The internal support system is a 420 mm×420 mm latticed column structure.Meanwhile,the monitoring and control of foundation pit supporting are strengthened during construction.According to the monitoring results,timely adjustment of construction parameters can better ensure the stability of the foundation pit of the pumping station and promote the smooth completion of the construction task of the rainwater pumping station.