市政工程软土深基坑分区组合支护设计

Design of Subarea Combined Support for Soft Soil Deep Foundation Pit of Municipal Works

地下水导致土层中出现软土,严重影响市政工程建筑施工的安全性,为此,设计一种市政工程软土深基坑分区组合支护方法,有效提升市政工程施工质量.考虑到建筑施工对象的地层地貌特点,针对深度较浅的基坑上道位置使用三轴水泥搅拌桩挡土墙实现软土支护;对于下道较深软土使用拉锚式排桩支护形式完成软土土体支护,两种方法分区组合,共同实现市政工程软土深基坑支护.设置监测点监测支护后的深基坑位移变化与轴力变化.结果显示,使用该方法支护软土后,软土深基坑具有良好的安全性能与稳定性能,位移与轴力在排除外部因素干扰下,并未超过预警值,安全性较高.

Underground-water causes soft soil in the soil layer,which seriously affects the safety of municipal project construction.Therefore,this paper designs a zoning combined support method for soft soil deep foundation pit to effectively improve the construction quality of municipal works.Considering the landform characteristics of relevant strata,tri-axial cement mixing pile retaining wall is used for the upper road of shallow foundation pit to realize soft soil support,and the pull anchor row pile support is used for the deep soft soil foundation.The two methods are combined in different areas to jointly realize the support of deep foundation pit in soft soil.Monitoring points are set to monitor the displacement change and axial force change of deep foundation pit after support.The results show that,after using this method to support soft soil,the deep foundation pit in soft soil has good safety and stability.Excluding the interference of external factors,the displacement and axial force do not exceed the early warning value,and the safety is high.