富水砂卵石地层深基坑降水特性及涌水量研究

Research on Dewatering Characteristics and Water Inflow of Deep Foundation Pit in Water Rich Sand and Pebble Strata

以洛阳市周山大道下穿开元大道路口明挖深基坑工程为依托,分析各降水参数改变对渗流场分布与降水效率的影响。通过Midas GTS NX有限元软件,模拟分析不同降水参数下降水井抽排地下水情况,同时建立了标准状态下涌水量特征曲线,并针对非标准状态提出涌水量修正方法。结果表明:除地层渗透系数改变地下水流速外,其他参数均会导致流网形态发生改变,与阻隔效应耦合后将间接影响降水速率。另外,通过工程实例验证考虑止水帷幕阻隔作用后的深基坑涌水量预测公式及其修正函数具有合理性,可应用于砂卵石地层深基坑降水工程。

Based on the open-cut deep foundation pit at the intersection of Kaiyuan Avenue undercrossing Zhoushan Avenue in Luoyang City,the impact of changes in precipitation parameters on the distribution of seepage field and precipitation efficiency is analyzed.The Midas GTS NX finite element software was used to simulate and analyze the pumping and drainage of groundwater from wells with different precipitation parameters.At the same time,a characteristic curve of water inflow under standard conditions was established,and a water inflow correc tion method was proposed for non-standard conditions.The results indicate that,except for the change in groundwater flow rate caused by the permeability coefficient of the formation,other parameters will cause changes in the flow network morphology,which will indirectly affect the precipitation rate when coupled with the barrier effect.Furthermore,through engineering examples,the rationality of the prediction formula and its correction function for the water inflow of deep foundation pits considering the blocking effect of the water stop curtain is verified,which can be applied to the dewatering engineering of deep foundation pits in sandy and gravel formations.