12
DOI:10. 7672/sgjs2017050012
施工技术
CONSTRUCTION TECHNOLOCY
2017年3月上第46卷第5期
深基坑开挖对邻近高速铁路桥墩桩基变形影响分析
郑明新"，夏一鸣，袁钎2，吴刚？
（1.华东交通大学道桥与岩土工程研究所，江西南昌330013；2.广州地铁集田有限公司
运营事业总部，广东广州510310）
【摘要】以福建莆田220kV框架保护涵下穿高速铁路莆田特大桥深基坑工程为背景，运用有限元软件ABAQUES建立二维数值模型，采用奠尔-库仑本构模型分析了基坑开挖过程，得到了基坑开挖过程中邻近基坑的桥墩墩台沉降和桩基变形规律：基坑开挖使桥墩桩基产生了附加变形，桥墩承台及桩基有明显向基坑发生水平移动趋势；同一桥墩各桩基最大水平位移均出现在基顶部，244号桥墩最大值为7.22mm，245号桥墩最大值为6.80mm；各桩基变形曲线呈缓S形，随着开挖深度增加，同一桩基距桩顶0~28m段桩基水平位移不断增大，但下半段桩基水平位移有背离基坑发生位移的趋势。通过实测数据和墩台沉降计算结果对比可知，数值模拟计算结果与实测数据大致吻合。
【关键词】深基坑；桩基础；变形；数值模拟
【中图分类号】TU43
【文献标识码］A
【文章编号】1002-8498(2017)05-0012-04
DeformationAnalysis of Pile of BridgePiers ofHigh-speedRailway
AffectedbyAdjacentDeepFoundationExcavation
Zheng Mingxin',Xia Yiming',Yuan Qian’,Wu Gang
(1. Institute of Bridge & Road and Geotechnical Engineering, East China Jicotong Unirersity, Nanchang, Jiangxi 330013, China; 2. Guangzhou Metro Group Co., Lid., Guangzhou, Guangdong 510310, China)
Abstract: Taking deep foundation excavation of frame protection culvert where undermeath passing bridge of high-speed railway for example, this paper analyzed deformation discipline of piers and piles where adjacent deep foundation by using finite element software to establish dimensional numerical model and applying to M-C model to simulate deep foundation excavation where adjacent to bridge piers of high-speed railway. The results show that foundation excavation causes additional internal forces and additional deformation of piles of piers and obvious tendency to move levelly to foundation; the maximum horizontal displacement of piles on the same piers placed on the top of the piles, and the maximum horizontal displacement of the piles of the No. 244 piers was 7. 22mm, and the piles of the No. 245 piers was 6. 8mm: the deformation curve of the piles of the No. 244 piers was consistent with No. 245 piers and was similar to S, as the depth of the foundation excavation, the level displacement where was apart from top of the piles with O ~ 28m decreased and moved to foundation, but the level displacement of the other part was depart from deformation. Calculated by comparing the measured results of the settlement data and
pier, obtained numerical simulation results are in good agreement with the experimental data Key words:deep foundation excavation; piles; deformation; simulation
引言
随着对国家基础设施建设投人加大，由于地理*国家自然科学基金项日（51208198）；江西省交通厅科研项目(2011H0019）
【作者离介］郑明新，教授，博士生导师，E-mail：zhengmx2002@ yahoo,cem
【收稿日期】2015-08-08：【修订日期】2016-01-16 万方数据
位置等原因，有时不能避免地需要在铁路路基或高速铁路桥墩附近因埋设管线或电缆，进而进行大规模开挖，这势必会对邻近路基或桥墩变形以及稳定性造成影响。然而目前国内外在深基坑开挖对高速铁路桥桥墩的影响这一领域研究较少，而对直接下穿高速铁路桥的基坑开挖对邻近桥墩影响方面的研究更是裹裹无几。潘振华曾利用大型有限元