不同支护形式结合处的基坑侧壁稳定性研究

Stability of Foundation Pit Side Walls at the Joint of Different Support Forms

在深基坑周围环境不同的情况下基坑应采用不同的支护形式,深基坑相邻的不同支护形式结合处(过渡段)的基坑侧壁是比较敏感的区域,容易发生变形不协调现象,因此需要对结合处的敏感区域进行研究。以郑州市城市道路交叉口、周边环境复杂的深基坑为研究对象,通过数值模拟和现场监测相结合的研究方法,对其双排桩支护方案与其相邻的桩锚支护方案的基坑侧壁结合处进行分析。研究结果表明:基坑开挖过程中两种支护方案的水平应力、水平位移、土压力等均有差别。随着开挖进行水平位移与水平应力逐渐增大。当开挖较深时,同一深度处桩锚支护侧水平位移大于双排桩支护侧水平位移、双排桩支护侧水平应力大于桩锚支护侧水平应力。

Different support forms should be adopted at different positions of deep foundation pits under different environmental conditions.The side walls of adjacent deep foundation pits at the junction of different support methods(transition section)are relatively sensitive areas,which are prone to deformation incompatibility.Therefore,it is necessary to analyze the sensitive areas at the junction.Taking the urban road intersection and complex surrounding environment of deep foundation pits in Zhengdong New District,Zhengzhou City as the research object,this work analyzed the joint of the double row pile support scheme and its adjacent pile anchor support scheme on the side wall of the foundation pit through a combination of numerical simulation,on-site monitoring,and rational calculation.The research results indicate that there are differences in horizontal stress,horizontal displacement,and soil pressure between the two support schemes during excavation of foundation pits.As excavation progresses,horizontal displacement and horizontal stress gradually increase.When excavating deeper,the horizontal displacement of the pile anchor support side at the same depth is greater than that of the double row pile support side,and the horizontal stress of the double row pile support side is greater than that of the pile anchor support side.