大型综合管廊深基坑变形机理及支护方案设计  

Research on Deformation Mechanism and Support Scheme Design of Deep Foundation Pits for Large-Scale Comprehensive Pipe Conduits

作　　者：王星 WANG Xing(China Railway 12th Bureau Group 3rd Engineering Co.Ltd.,Taiyuan Shanxi 030024,China)

机构地区：[1]中铁十二局集团第三工程有限公司,山西太原030024

出　　处：《铁道建筑技术》2025年第4期106-108,165,共4页Railway Construction Technology

基　　金：中铁十二局集团有限公司科技研发计划项目(2020-34)。

摘　　要：基坑开挖导致周边土体应力产生重分布,设计及施工不当易导致基坑失稳,破坏周边环境。针对基坑稳定性问题,分析不同加固措施下基坑周边土体变形演化特征,研究插筋、土钉和预应力锚杆,混凝土面层及绿色装配式面层对支护效果的影响机制。结果表明:(1)基坑随开挖深度的增加,土体水平位移逐渐增大,无支护措施、混凝土面层支护及绿色装配式面层支护下最大水平位移分别为48.63、31.08及31.05 mm;混凝土面层替换为绿色装配式面层后,水平位移变化较小,但最大水平位移出现位置产生变化。(2)随基坑开挖深度增加,周边土体隆起位移不断增大,采用插筋和土钉对二级放坡进行共同支护后,位移显著降低。(3)土钉和插筋支护可有效限制土体侧向变形,配合面层共同作用有利于维持基坑稳定。Excavation of foundation pits can cause stress redistribution in the surrounding soil,and improper design and construction can easily lead to instability of the foundation pit and damage to the surrounding environment.In response to the stability issue of foundation pits,the deformation evolution characteristics of the surrounding soil under different reinforcement measures were analyzed,and the influence mechanisms of reinforcing bars,soil nails,prestressed anchor rods,concrete surface layers,and green prefabricated surface layers on the support effect were studied.The research results show that:(1)with the increase of excavation depth,the horizontal displacement of the soil gradually increases in the foundation pit.The maximum horizontal displacement under non-support measures,concrete surface support,and green prefabricated surface support are 48.63 mm,31.08 mm,and 31.05 mm,respectively.When replacing the concrete surface layer with a green prefabricated surface layer,the horizontal displacement changes slightly,but the location of the maximum horizontal displacement changes;(2)as the excavation depth of the foundation pit increases,the uplift displacement of the surrounding soil continues to increase.After using reinforcing bars and soil nails to jointly support the secondary slope,the displacement is significantly reduced;(3)after soil nailing and reinforcement support,it can effectively limit the lateral deformation of the soil,and the combined effect of the surface layer is conducive to maintaining the stability of the foundation pit.

关 键 词：基坑变形 机理分析 数值模拟 支护方案 

分 类 号：TU473.2[建筑科学—结构工程]