机构地区:[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都610059 [2]国网四川省电力公司经济技术研究院,成都610041
出 处:《成都理工大学学报(自然科学版)》2023年第6期744-755,共12页Journal of Chengdu University of Technology: Science & Technology Edition
基 金:国家自然科学基金青年科学基金项目(41907246)。
摘 要:为了客观分析复杂环境基坑中不同组合支护下深基坑的变形响应特征和支护结构的变形协调作用,定量评价支护作用效果,以成都市区某变电站深基坑工程为依托,结合监测资料,采用FLAC^(3D)对该基坑各开挖支护阶段进行数值反演,对比研究不同支护土体开挖过程中的坑壁侧移、地表沉降及考虑多因素的支护综合作用效果,揭示基坑响应规律。研究表明:桩撑式结构水平约束能力较强,桩锚式支护抗沉降效果明显,结合2种组合结构可同时控制地表沉降和基坑顶部的侧向变形;减小锚索施加角度可有效减小空间效应的影响,桩锚式支护空间横向约束效果较好,但桩身弯矩和剪力较大;模糊综合评价结果表明2种组合支护方案可以更好地协调复杂环境适应性与结构变形能力;对比其他基坑案例,本基坑围护结构侧移及地表沉降较小,围护结构侧移最大值δ_(hm)介于(0.02%~0.13%)H_(e)(H_(e)为开挖深度)之间,地表沉降最大值δ_(vm)介于(0.03%H_(e)-1.6)~(0.03%H_(e)-4.1)之间,线性拟合结果为δ_(vm)=0.15δ_(hm)。研究结果可为同样复杂环境条件下,以安全和经济效益为主控因素的深基坑工程提供参考。The deformation response characteristics of deep foundation pit under different combinations of supports in complex environment and the deformation coordination function of supporting structure are analyzed in order to quantitatively evaluate the effect of supporting function.Based on the monitoring data of a substation deep foundation pit project in Chengdu urban area,this study uses FLAC^(3D) to conduct numerical inversion for each excavation and support stage of the foundation pit,studies and compares the lateral displacement of pit wall and surface settlement during excavation of different supporting soil,and considers the comprehensive effect of multiple factors of support,so as to reveal the response rule of foundation pit.The results show that the pile-supported structure has strong horizontal restraint ability,and the pile-anchored support has obvious anti-settlement effect.The combination of the two structures can simultaneously control the surface settlement and the lateral deformation of the foundation pit top.Meanwhile,reducing the application angle of anchor cable can effectively reduce the influence of space effect,and the spatial transverse restraint effect of pile-anchor support will be better,but it will cause a larger pile bending moment and shear force.The results of fuzzy comprehensive evaluation show that the two combined support schemes can better coordinate the adaptability of complex environment and the deformation ability of structure.Compared with other foundation pit cases,the lateral displacement and surface settlement of this foundation pit are relatively small.The maximumδ_(hm) of the lateral displacement of the foundation pit is between 0.02%and 0.13%H_(e)(H_(e) is the excavation depth),and the maximumδ_(vm) of the surface settlement is between(0.03%H_(e)-1.6)and(0.03%H_(e)-4.1),with a linear fitting result ofδ_(vm)=0.15δ_(hm).The research results in this paper can provide reference for deep foundation pit engineering with safety and economic benefit under the same complex envir
关 键 词:变电站深基坑 组合支护 监测数据 数值反演 模糊综合评价 支护响应
分 类 号:TU753[建筑科学—建筑技术科学]
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