青岛地铁北站超大型基坑支护设计

结合场地土质及水文条件,在明确工程特点及难点的情况下对围护结构和支撑形式的选择进行了具体分析,确定了围护结构采用钻孔灌注桩+桩后高压旋喷桩作止水帷幕,各单个基坑由于开挖深度不同采用不同支护形式的方案;在围护结构内力计算中,建立了钻孔灌注桩+内支撑、双排悬臂钻空灌注桩两种计算模型,并以国铁站房基坑为例,利用理正深基坑计算程序对围护结构建立模型进行了内力计算,其结果满足变形要求,基坑稳定性验算得出围护结构抗倾覆稳定性也满足要求;最后阐述了几点结论,对类似工程有一定的参考价值。

Design of Large Excavation Supporting of Qingdao Metro North Station

According to the engineering geology and hydrology geology, on a basis of analyzing the excavation＇s characteristic feature and difficulties, we have made a concrete analysis about the choice of the form on outer protective structure and support, then determined the programs that the outer protective structure＇s Water Stop Curtain is made by Bored Pile and the High Pressure Jet Grouting Spin- pile and the single excavation adopted different support forms due to different depth; in the calculation of the support＇ s internal force, we have established two calculation models including Bored Pile and internal bracing and double cantilever Bored Pile,take the railway station building as an illustration, we have used Lizheng procedures for deep excavation to calculate internal force in accordance with the model of the envelope, the result meets the requirement of the excavation deformation, the foundation pit stability checks that palisade structure resistance to capsize stability also meets the requirement. Finally, some experience is evaluated, which maybe has reference meaning for excavation project for the future.