复合立柱桩支承下深基坑围护结构变形性状
|
摘要
研究目的:基坑工程中支护结构与主体结构相结合,不仅对基坑稳定性有着重要影响,而且还具有较大的工程应用价值。本文以济南轨道交通R1线演马庄西站基坑工程为例,针对车站主体结构永久立柱兼作竖向临时支撑这一新型结构形式建立三维数值计算模型,以挡墙围护结构的水平侧移作为基坑稳定和安全性评价指标,讨论立柱桩的插入比、直径和间距等因素变化对基坑挡墙结构侧移的影响,并给出在济南黄河厚冲积地层条件下深基坑支护体系中立柱相关参数的取值建议。研究结论:(1)增加立柱桩插入比对围护桩的约束起到的作用有限,类似条件工程的插入比建议值为0.5～0.7;(2)立柱桩直径为400～500 mm时,能够有效地限制围护桩的水平侧移;(3)立柱桩间距对围护桩的水平侧移存在一定的影响,类似条件工程的立柱桩间距建议值为7.5～9.5 m;(4)本研究成果可应用于采用新型支护方法的深基坑工程设计与施工中。
Research purposes:The combination of the supporting structure and the main structure in the foundation pit engineering not only has an important influence on the stability of the foundation pit,but also has great engineering application value.Taking the foundation pit of the West Yanmazhuang subway station of Jinan rail transit R1 line as an engineering example,a three-dimensional numerical model was established to simulate the new type of structure,i.e.the permanent pillar of the main structure of station is also served as the vertical temporary support.The horizontal displacement of the retaining wall was adopted as an evaluation index to evaluate the stability and safety of foundation pits,the influence of the factors such as the insertion ratio,diameter and spacing of the pillar pile on the lateral displacement of the retaining wall structure was discussed.Finally,the recommendations for the relevant parameters of the columns in the support system for deep foundation pits under the condition of the thick alluvial formations of the Yellow River.Research conclusions:(1) Increasing the insertion ratio of column piles is limited for the restraint of the retaining piles,and the proposed insertion ratio of similar condition engineering is 0.5～0.7.(2) When the pillar pile diameter is 400 mm～500 mm,horizontal lateral displacement of the retaining pile can be effectively limited.(3) There is a certain influence on the horizontal lateral displacement of the retaining piles,and the suggested value for the column spacing of similar conditions is 7.5 m～9.5 m.(4) The research results can be applied to the design and construction of the new support methods for the deep foundation pit projects.
Research purposes:The combination of the supporting structure and the main structure in the foundation pit engineering not only has an important influence on the stability of the foundation pit,but also has great engineering application value.Taking the foundation pit of the West Yanmazhuang subway station of Jinan rail transit R1 line as an engineering example,a three-dimensional numerical model was established to simulate the new type of structure,i.e.the permanent pillar of the main structure of station is also served as the vertical temporary support.The horizontal displacement of the retaining wall was adopted as an evaluation index to evaluate the stability and safety of foundation pits,the influence of the factors such as the insertion ratio,diameter and spacing of the pillar pile on the lateral displacement of the retaining wall structure was discussed.Finally,the recommendations for the relevant parameters of the columns in the support system for deep foundation pits under the condition of the thick alluvial formations of the Yellow River.Research conclusions:(1) Increasing the insertion ratio of column piles is limited for the restraint of the retaining piles,and the proposed insertion ratio of similar condition engineering is 0.5～0.7.(2) When the pillar pile diameter is 400 mm～500 mm,horizontal lateral displacement of the retaining pile can be effectively limited.(3) There is a certain influence on the horizontal lateral displacement of the retaining piles,and the suggested value for the column spacing of similar conditions is 7.5 m～9.5 m.(4) The research results can be applied to the design and construction of the new support methods for the deep foundation pit projects.
引文
[1]王渭明,严纪兴,赵增辉.黄河冲积地层深基坑支护优化及应用研究[J].地下空间与工程学报,2016(1):176-180.Wang Weiming,Yan Jixing,Zhao Zenghui.Research on Supporting Optimization and Applications of Deep Foundation Pit in the Yellow River Alluvial Formation[J].Chinese Journal of Underground Space and Engineering,2016(1):176-180.
[2]毛金萍,徐伟,吕鹏.深基坑立柱竖向位移分析[J].建筑技术,2004(5):342-343.Mao Jinping,Xu Wei,Lv Peng.Vertical Displacement Analysis of Erect Column in Deep Foundation Pit[J].Architecture Technology,2004(5):342-343.
[3]喻军.深基坑开挖过程中立柱受力变化规律分析[J].施工技术,2013(19):43-44,117.Yu Jun.Analysis on the Law of the Pillar Bearing Force During Deep Excavation[J].Construction Technology,2013(19):43-44,117.
[4]楼晓明,杨晶,李德宁,等.立柱桩在深基坑分步开挖过程中的上拔位移分析[J].岩土工程学报,2013(1):193-198.Lou Xiaoming,Yang Jing,Li Dening,etc.Uplift Displacement of Soldier Piles During Stepped Excavation of Deep Foundation Pits[J].Chinese Journal of Geotechnical Engineering,2013(1):193-198.
[5]王利民,吴波,张俊.内撑式基坑立柱桩竖向位移分析[J].施工技术,2016(5):107-110.Wang Limin,Wu Bo,Zhang Jun.Analysis of the Vertical Displacements for Column Piles in Internal Bracing Foundation Excavation[J].Construction Technology,2016(5):107-110.
[6]翟礼嘉,丁智,王金艳.基坑立柱桩隆起分析及简化计算[J].岩土工程学报,2014(S2):70-76.Zhai Lijia,Ding Zhi,Wang Jinyan.Simplified Calculation of Heaving of Soldier Piles During Excavation of Foundation Pits[J].Chinese Journal of Geotechnical Engineering,2014(S2):70-76.
[7]李连祥,刘兵,李先军.支护桩与地下主体结构相结合的永久支护结构[J].建筑科学与工程学报,2017(2):119-126.Li Lianxiang,Liu Bing,Li Xianjun.Permanent Supporting Structure Combined with Supporting Piles and Underground Structure[J].Journal of Architectural and Civil Engineering,2017(2):119-126.
[8]汤华涛,吴新跃.体壳单元连接MPC法的计算精度分析[J].现代制造工程,2011(7):62-65.Tang Huatao,Wu Xinyue.Calculation Precision of Multipoint Constraint Technology Used to Solve Combination Model of Solid Element and Shell Element[J].Modern Manufacturing Engineering,2011(7):62-65.
[2]毛金萍,徐伟,吕鹏.深基坑立柱竖向位移分析[J].建筑技术,2004(5):342-343.Mao Jinping,Xu Wei,Lv Peng.Vertical Displacement Analysis of Erect Column in Deep Foundation Pit[J].Architecture Technology,2004(5):342-343.
[3]喻军.深基坑开挖过程中立柱受力变化规律分析[J].施工技术,2013(19):43-44,117.Yu Jun.Analysis on the Law of the Pillar Bearing Force During Deep Excavation[J].Construction Technology,2013(19):43-44,117.
[4]楼晓明,杨晶,李德宁,等.立柱桩在深基坑分步开挖过程中的上拔位移分析[J].岩土工程学报,2013(1):193-198.Lou Xiaoming,Yang Jing,Li Dening,etc.Uplift Displacement of Soldier Piles During Stepped Excavation of Deep Foundation Pits[J].Chinese Journal of Geotechnical Engineering,2013(1):193-198.
[5]王利民,吴波,张俊.内撑式基坑立柱桩竖向位移分析[J].施工技术,2016(5):107-110.Wang Limin,Wu Bo,Zhang Jun.Analysis of the Vertical Displacements for Column Piles in Internal Bracing Foundation Excavation[J].Construction Technology,2016(5):107-110.
[6]翟礼嘉,丁智,王金艳.基坑立柱桩隆起分析及简化计算[J].岩土工程学报,2014(S2):70-76.Zhai Lijia,Ding Zhi,Wang Jinyan.Simplified Calculation of Heaving of Soldier Piles During Excavation of Foundation Pits[J].Chinese Journal of Geotechnical Engineering,2014(S2):70-76.
[7]李连祥,刘兵,李先军.支护桩与地下主体结构相结合的永久支护结构[J].建筑科学与工程学报,2017(2):119-126.Li Lianxiang,Liu Bing,Li Xianjun.Permanent Supporting Structure Combined with Supporting Piles and Underground Structure[J].Journal of Architectural and Civil Engineering,2017(2):119-126.
[8]汤华涛,吴新跃.体壳单元连接MPC法的计算精度分析[J].现代制造工程,2011(7):62-65.Tang Huatao,Wu Xinyue.Calculation Precision of Multipoint Constraint Technology Used to Solve Combination Model of Solid Element and Shell Element[J].Modern Manufacturing Engineering,2011(7):62-65.