柱洞法在北京地铁车站工程施工中的应用

以北京地铁15号线学院路站为研究背景,通过查阅资料、咨询专家并进行数值模拟等手段,确立了对导洞内土体进行深孔劈裂注浆措施,加固土体并形成隔水层,取代了传统的地面降水,节约了场地,消除了因降水造成地层水土流失而引起周边建(构)筑物的不均匀沉降,也避免了城市地下水资源浪费。将原来柱洞法的6导洞改为8导洞,钻孔灌注桩改为人工挖孔桩,并对车站结构施工工序进行了优化。工程实践表明,修改后的施工方案缩短了工期,提高了施工效率,效益较好。

Application of PBA Underground Excavation Method in Beijing Metro Station Construction

Based on Xuanyuan Road Station of Beijing metro Line 15,the measures of deep hole fracture grouting are taken through data search,expert consultation and numerical simulation.By this way,the place of the traditional ground surface dewatering is taked by the reinforcement of the soil to format the water-resisting layer.It saves space,eliminates the uneven settlement of the surrounding buildings caused by soil erosion because of dewatering,and circumvents the waste of groundwater resources.This method optimizes the PBA excavation method from 6 guide holes to 8 guide holes,from bored piles to artificial drilled piles,and the working procedure of the station structure as well.The engineering practice shows that the optimized construction technique can shorten the project time limit,improve the efficiency of construction and bring about larger benefit.