地铁车站超大深基坑工程支护结构深化施工技术

Deepening Construction Technology of Supporting Structure in Super Deep Foundation Excavation of Subway Stations

结合济南西客站地铁6号线超大深基坑工程,阐述了适合该工程地质条件的深化施工技术,即"一、二级平台、三级放坡"和利用"时空效应"的开挖方法基础上,综合应用网喷支护、钢管内支撑等支护体系以及加强技术措施,并采用双轴水泥搅拌桩和高压旋喷桩作为止水帷幕的综合施工方案。为了进一步验证该支护结构施工方案的合理性、确保基坑支护结构的安全,采用有限元软件ANSYS对二级基坑支护桩顶的水平位移进行模拟分析,最后通过对支护体系的施工监测结果与有限元计算结果对比分析可知,该深化施工技术方案合理有效,达到了预期的效果。

According to oversized deep foundation excavation engineering of the 6th city subway line of the Ji＇nan West Railway Station, this paper introduces deepening construction technology of the special geological conditions, including excavation technique of first level platform, secondary level platform and tertiary slope using space-time effect, compounding reinforcing method of sprayed anchor net supporting technique and interior supporting of steel pipe, as well as controlling ground water effectively by adopting high pressure spray pile and dual axle cement mixing pile. Moreover, the finite element software ANSYS is used to analysis displacement of supporting piles top to ensure safety. Finally, the monitoring results and simulation results are compared to ensure the reasonable and effective deepening construction technology and reach the desired effect.