城市综合管廊基坑 SMW 工法桩变形影响研究
作者简介:
韩伟奇,项目经理,高级工程师,E-mail:923040508@qq. com
作者单位:
中铁十八局集团第四工程有限公司,天津 300500
基金项目:
∗中铁十八局集团有限公司科技计划(G20-08)
摘要:
城市地下综合管廊基坑施工面临土层强度低、变形控制要求严格等难题,为明确基坑围护结构变形调控机制,对 SMW 工法桩+混凝土支撑+钢支撑组合围护结构进行分析,研究围护桩插入比、支撑道数、支撑间距的影响,并提出参数耦合优化+动态控制的施工措施,使桩顶位移控制在限值内。研究结果表明,管廊基坑围护结构水平和竖向位移呈缓增-陡增-回落趋于稳定的演化特征,围护桩插入比宜控制在 1.1~ 1.2,支撑间距宜设置为 3m 左右,施作 1 道混凝土支撑+1 道钢支撑可满足安全要求,必要时可增设 2 道钢支撑,以更好地控制围护结构变形。

English:
The construction of urban underground integrated pipe gallery foundation excavation faceschallenges such as low soil strength and strict deformation control requirements. To clarify the deformationcontrol mechanism of the foundation excavation enclosure structure, an analysis was conducted on theSMW pile+concrete support+steel support combination enclosure structure. The influence of the insertionratio of enclosure piles, the number of support channels, and the spacing between supports was studied,and construction measures of parameter coupling optimization and dynamic control were proposed tocontrol the displacement of the pile top within the limit. The research results indicate that the horizontaland vertical displacement of the enclosure structure of the pipe gallery foundation excavation shows agradual increase, a steep increase, and a stable decline trend. The insertion ratio of enclosure pilesshould be controlled at 1.1~1.2, and the support spacing should be set at about 3m. The construction ofone concrete support and one steel support can meet the safety requirements. If necessary, two steelsupports can be added to better control the deformation of the enclosure structure.