航道开挖过程中加固结构对桩土变形影响分析  

Analysis of influence of reinforcement structure on pile-soil deformation during channel excavation

作　　者：张薇 曹军[2] 顾祯雪 余杰 宋德威 孙阳[1,4] ZHANG Wei;CAO Jun;GU Zhen-xue;YU Jie;SONG De-wei;SUN Yang(College of Harbour, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China;Nanjing Hydraulic Research Institute, Nanjing Hydraulic Research Institute Survey and Design Co. Ltd., Nanjing 210098, China;Hangzhou Jinghang Canal Second Channel Construction Investment Co. Ltd., Hangzhou 330104, China;Huai′an Research Institute of Hohai University, Huai′an 223001, China)

机构地区：[1]河海大学港口海岸与近海工程学院,南京210098 [2]南京水利科学研究院南京水科院勘测设计有限公司,南京210098 [3]杭州京杭运河二通道建设投资有限公司,杭州330104 [4]河海大学淮安研究院,淮安223001

出　　处：《水道港口》2022年第2期258-265,共8页Journal of Waterway and Harbor

基　　金：国家自然科学基金项目(41672257);浙江省交通运输厅科技计划项目(2020014);南通市科技项目(JC2021009)。

摘　　要：新挖航道下穿已有高铁工程的施工过程中,航道基坑-周围地层-高铁桩基是一个共同变形的复杂体系,应从整体上对下穿段进行加固,如何选取既安全可靠又经济合理的加固方案,是设计阶段密切关注的问题。以京杭运河二通道(杭州段)新开挖航段为工程背景,基于强度折减法建立了不同开挖工况以及不同加固方案下的数值模型,讨论了整个开挖过程中滑移面情况和桥墩的变形,分析了不同的加固结构对土体位移及桥墩变形的影响规律。结果显示:围护桩与水泥搅拌桩在土体位移的减少和控制桥墩变形方面效果显著,且两者侧重阶段不同,而在河床底面铺砌混凝土对地基加固的效果不是十分明显。总体来说,围护桩、水泥搅拌桩、混凝土护坡三者配合使用可以在整个开挖过程中减少土体位移及桥墩变形。During the construction of the newly channel underneath the existing high-speed rail project,foundation pit,surrounding stratum and high-speed railway pile foundations are a complex system that deforms together,so the undercrossing section should be reinforced as a whole.How to choose a safe,economical and reasonable reinforcement scheme is a problem that should be paid close attention to in the design stage.Taking the newly excavated section of the second channel of the Beijing-Hangzhou Canal(Hangzhou section)as the engineering background,numerical models under different excavation conditions and different reinforcement schemes based on strength reduction method were established.The slip surface condition and pile foundation deformation during the whole excavation process were discussed,and the influence of different reinforcement structures on soil displacement and pile deformation was analyzed.The results show that the retaining piles and cement mixing piles have significant effects in reducing soil displacement and controlling pile deformation,and they focus on different stages,while the effect of concrete on the bottom of the channel is not very obvious.In general,the combined use of retaining piles,cement mixing piles,and concrete slope protection have a very good reinforcement effect on the entire structure.

关 键 词：航道开挖 桩-土作用 强度折减法 数值计算 加固措施优化 

分 类 号：U611[交通运输工程—船舶及航道工程]