通过在传统西原本构模型中串联Newton体,可准确追踪黄河厚冲积黏土地层中土体卸荷后的非稳定蠕变力学行为特征。以济南省文化艺术中心大厦深基坑为工程背景,采用现场监测数据分析、统计建模和FLAC3D二次开发数值模拟相结合的方法进行模型优化和改进西原方程的参数辨识,分析了围护桩的不同插入比、桩边尺寸及桩间净距3种情况下基坑卸荷导致的底板上移规律,以及立柱桩入土深度、插桩位置及桩型对基坑开挖过程中立柱桩的回弹特性的影响。结果表明底板上移对参数的敏感程度大小为围护桩净距＞插入比＞桩边长;立柱桩回弹对参数的敏感程度大小为立柱桩入土深度＞插桩位置＞桩型。利用此规律可有效降低基坑开挖对工程桩及底板隆起的影响,确保了济南省文化艺术中心大厦深基坑的施工安全、优质,为同类地层深基坑控制立柱桩及底板隆起提供了设计经验和参考。
Abstract
The upward displacement of pile and floor is a damage for the balance of support system during the excavation foundation of pit in thick alluvial clay Nishihara model improved with Newton fluid could well describe the behavior of creep deformation during pit excavation,and also trace the behavior of interface between pile and soil.The regularities of upward displacement of floor in the presence of different ratios of inserted pile depth to excavation depth,side lengths and spacings of support pile,as well as the rebound of column pile in the presence of different depths in soil,positions and types of column pile were analyzed via field data,improved Nishihara model and secondary development of FLAC3D.The deep foundation pit of Culture Center of Jinan Province was taken as an engineering background.Results revealed that the sensitivity of the upward displacement of pit floor to different factors follows the order of:distance of adjacent support pile>ratio of inserted depth to excavation depth>length of support pile; and the sensitivity of the rebound of column pile follows the order of depth of column pile in soil>position of pile>shape of plie. The results could be a guidance for reducing the influence of excavation on the upward displacement of pile and floor.
关键词
改进西原模型 /
厚冲积地层 /
底板隆起 /
立柱桩回弹 /
敏感性分析
Key words
improved Nishihara model /
thick aluvial /
rebound of foundation pit /
column pile rebound /
sensitivity analysis
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] 若 枫,马 郧,徐光黎,等.基坑被动区阶梯式加固尺寸对桩位移影响分析[J]. 长江科学院院报,2013,30(7):86-90,100.
[2] 李方成,郭利娜,胡 斌,等.基于MIDAS软件探讨施工工序对深基坑稳定性的影响[J]. 长江科学院院报,2013,3(3):49-55.
[3] 陈 明,李镜培. 砂土地基中开挖过程对立柱桩的影响分析[J]. 力学与实践,2014,36(1):59-63.
[4] 贺 翀. 深基坑的立柱桩隆起计算[J].岩土工程学报,2010,32(增1):74-78.
[5] 陈锦剑,王建华,范 巍,等.抗拔桩在大面积深开挖过程中的受力特性分析[J].岩土工程学报,2009,31(3):402-407.
[6] 王文灿,刘 琦,仲晓梅.超深基坑立柱竖向位移及其对水平结构的影响数值模拟[J].建筑结构,2011,41(增刊):1344-1349.
[7] 卫凌云,秦胜伍,陈慧娥.基坑开挖对单桩及群桩回弹位移的影响分析[J].吉林大学学报(地球科学版),2014,44(2):584-590.
[8]IWASAKI Y, WTNABE H, FUKUDA M, et al. Construction Contrl for Underpinnig Piles and Their Behaviour Duing Excavation[J]. Geotechnique,1994,44(4):681-689.
[9]POULOS H G, DAVIE E H. Pile Foundation Analysis and Design[M]. New York: Wiley, 1980.
[10]代春泉,秦 哲,苏建光.黄河冲积平原深基坑施工变形黏弹塑性分析[J].岩土力学,2013,34(增1):142-147.
[11]徐 飞,王渭明,张乾青,等.黄河冲积平原地区超大型深基坑开挖现场监测分析[J].岩土工程学报,2014,36(增2):471-478.
[12]代春泉,王 磊,王渭明.基于各向异性本构模型的隧道支护控制[J].北京工业大学学报,2012,38(8):1202-1207.
[13]梁发云,褚 峰,宋 著,等.深基坑变形特性的离心模型试验、数值计算与现场实测对比分析[J].长江科学院院报,2012,29(1):74-78.
[14]连宝琴,胡 斌,王新刚,等.武汉地铁名都车站基坑开挖监测与数值分析[J].长江科学院院报,2014,31(5):34-38.
[15]王孝兵,文松霖,徐文强.大直径长桩接触面参数的敏感性分析[J]. 长江科学院院报,2011,28(2):38-44,55.
[16]宋德彰,孙 钧.岩质材料非线性流变属性及其力学模型[J]. 同济大学学报, 1991,19(4): 395－401.
[17]徐 伟,李靖祺,段朝静.某特殊平面形状深基坑围护结构对土层参数敏感性分析[J].岩土工程学报,2010,32(增1):173-176.
[18]贾海莉,王成华,李江洪.基于土拱效应的抗滑桩与护壁桩的桩间距分析[J]. 工程地质学报, 2004, 12(1):98-103.
[19]杨有海,武进广.杭州地铁秋涛路车站深基坑支护结构性状分析[J]. 岩石力学与工程学报,2008, 27(增2):3386-3392.
基金
山东省自然科学基金项目(ZR2014EEM029,ZR2014EEQ028);山东省重点研发项目(2015GSF120017);住房城乡建设部2015年科学技术项目计划-研究开发项目(2015-K5-004);山东省住房和城乡建设厅科学技术计划项目(KY053)
PDF(1985 KB)
