摘要
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。
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 FLAC3 D.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.
出处
《长江科学院院报》
CSCD
北大核心
2016年第10期84-92,共9页
Journal of Changjiang River Scientific Research Institute
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)
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
improved Nishihara model
thick aluvial
rebound of foundation pit
column pile rebound
sensitivity analy sis
