SMW工法在德大铁路下穿京沪高铁U形槽基坑支护中的应用

摘要

Combined with the application of SMW method on the retaining and protecting for foundation excavation of U - shaped structure at Dezhou-Dajiawa Railway crossing under Beijing - Shanghai High-Speed Railway, the design theory, calculation method and construction technology of SMW method are introduced and analyzed. Stresses and deformations of supporting structure are calculated by means of beam on elastic foundation method, and practical construction process of supports installation and foundation excavation are simulated and calculated by incremental method. The result shows that reasonable excavation scheme of foundation pit, the effective pre-axial force in inner steel pipe supports and the application of cement-mixed piles at the bottom of foundation pit can be beneficial to reduce the horizontal deformation on the wall. Real-time monitoring, measurement, and analysis for the supporting structure during construction can efficiently ensure the successful construction of foundation pit as well as ensure the safety of the surroundings .%结合SMW工法在德大铁路下穿京沪高速铁路U形槽基坑支护中的应用,对SMW工法设计理论、计算方法及施工工艺进行介绍和分析,采用平面弹性地基梁法分析围护结构的受力和变形,并采用增量法模拟计算设置支撑和开挖的实际施工过程.结果表明,合理的选择基坑开挖方案、有效的设置钢管内支撑预加轴力以及采用坑底设置水泥搅拌桩,均有利于减小墙体的水平变形.施工过程中对围护结构进行实时监控、量测、分析,可有效的保证基坑的顺利施工和周边环境的安全.