Abstract: The excavation of deep foundation pit of natural foundation of super high-rise building in weathered sandstone area of Lanzhou is the first foundation pit excavation project of natural foundation in Gansu Province. The mechanical characteristics of foundation pit excavation are affected by excavation method, soil layer and mechanical properties. In this paper, triaxial test and finite element numerical simulation are used to analyze the change of surrounding mechanical properties caused by foundation pit excavation in this area. The shear strength parameters of weathered sandstone are obtained by triaxial test, and the three-dimensional numerical model of foundation pit excavation is established by using finite element numerical simulation software. The stress and deformation curves in the process of foundation pit excavation are obtained. The simulation results are compared with the current specifications, and the feasibility scheme of foundation pit excavation is obtained, which provides reference for similar projects in the future.- DOI:10.3969/j.issn.1000-1565.2020.05.003风化砂岩地区超高层建筑基坑开挖的力学特征余莉^1,2,3,蒋宗鑫⁴,闫名卉³,赵拓¹(1.河北省建筑科学研究院有限公司,河北 石家庄 050000;2.石家庄铁道大学 土木工程学院,河北 石家庄 050043;3.河北大学 建筑工程学院,河北 保定 071002;4.甘肃中建市政工程勘察设计研究院有限公司,甘肃 兰州 730000)摘 要:兰州市风化砂岩地区超高层建筑天然地基的深基坑开挖是甘肃省首项天然地基的基坑开挖工程,其开挖方式、土层情况、力学性质等不同程度地影响着基坑开挖的力学特征.本文采用三轴实验和有限元数值模拟,分析该地区基坑开挖引起周围力学性质的变化情况.通过三轴实验获取风化砂岩的剪切强度参数,利用有限元数值模拟软件建立基坑开挖的三维数值模型,得到基坑开挖过程中的应力和变形曲线,并将模拟结果与现行规范进行对比分析,得到基坑开挖的可行性方案,为以后的类似工程提供参考意见.关键词:强风化砂岩;基坑开挖;数值模拟;变形中图分类号:TU44 文献标志码:A 文章编号:1000-1565(2020)05-0461-08Mechanical characteristics of foundation pit excavation of super high-rise building in weathered sandstone areaYU Li^1,2,3,JIANG Zongxin⁴,YAN Minghui³,ZHAO Tuo¹(1. Hebei Academy of Building Sciences Co., Ltd., Shijiazhuang 050000,China; 2.School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;;3.College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China;4.Gansu Zhongjian Municipal Engineering Survey Design and Research Institute Co., Ltd.,Lanzhou 730000,China)Abstract: The excavation of deep foundation pit of natural foundation of super high-rise building in weathered sandstone area of Lanzhou is the first foundation pit excavation project of natural foundation in Gansu Province. The mechanical characteristics of foundation pit excavation are affected by excavation method, soil layer and mechanical properties. In this paper, triaxial test and finite element numerical simulation are used to analyze the change of surrounding mechanical properties caused by foundation pit excavation in this area. The shear strength parameters of weathered sandstone are obtained by triaxial test, and the three-dimensional numerical model of foundation pit excavation is established by using finite element numerical simulation software. The stress and deformation curves in the process of foundation pit excavation are obtained. The simulation results are compared with the current specifications, and the feasibility scheme of foundation pit excavation is obtained, which provides reference for similar projects in the future.- 收稿日期:2019-04-27 基金项目:河北省教育厅青年拔尖人才资助项目(BJ2018046) 第一作者:余莉(1985—),女,四川安县人,河北大学副教授,博士后,主要从事岩土工程方面的研究.E-mail:964630415@qq.com 通信作者:闫名卉(1993—),女,河北唐山人,河北大学在读硕士研究生,主要从事岩土工程方面的研究. E-mail:2803530599@qq.com第5期余莉等:风化砂岩地区超高层建筑基坑开挖的力学特征

Key words: strongly weathered sandstone, foundation pit excavation, numerical simulation, deformation