Characteristics of surface settlement and deformation of open cut foundation pit in different areas of Beijing
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摘要:
基于近年北京地区不同区域大量明挖基坑工程地表沉降实测数据，利用理论计算与回归分析方法，对预测地表沉降的典型曲线“四点折线法”及其模型参数（斜率K及截距b）进行了反演分析，获得了不同区域地质条件下明挖基坑地表沉降预测经验参数；通过对沉降数据及经验参数的统计分析，总结了地表沉降区域变化规律，明确了参数的取值范围，并利用实测数据验证了经验参数的预测精度。结果显示：北京西部区域最大沉降点距离围护结构的水平距离相对中、东部偏大，约为基坑深度的30%，中、东部区域相对较小，均约为基坑深度的26%；地表沉降曲线形态随着区域地质条件不同而不同，四点折线图第一段直线AB的斜率K的绝对值由西向东依次增大，表明东部粉细砂地层比西部砂卵石地层沉降坡度更加明显，第二段直线BC的斜率K的绝对值东部区域比西部区域反而较小，这表明东部区域的沉降影响范围较大；参数bAB绝对值均值由西向东依次增大，表明东部粉质黏土、细沙层相对西部砂卵石地层的桩侧土体沉降值更大，约为最大沉降值的31%，中部区域为21%，西部区域仅为16%。该研究成果将为本地区明挖基坑工程地表变形预测和安全风险控制提供重要的参考依据。
Abstract:Based on a large number of measured data of surface settlement of open cut foundation pit engineering in different areas of Beijing in recent years, the typical curve "Four Point Broken Line Method" and its model parameters (slope K and intercept b) for predicting surface settlement are inversely analyzed by using theoretical calculation and regression analysis methods, and the empirical parameters for predicting surface settlement of open cut foundation pit under different regional geological conditions are obtained. Based on the statistical analyses of data and empirical parameters, the regional variation law of surface subsidence is summarized, and the range of parameters is defined. The prediction accuracy of empirical parameters is verified by using the measured data. The results show that the horizontal distance between the maximum settlement point and the retaining structure in the west of Beijing is larger than those in the middle and east of Beijing, which is about 30% of the depth of the foundation pit, while those in the middle and east of Beijing is relatively small, which are about 26% of the depth of the foundation pit. The surface settlement curve shape varies with the regional geological conditions, and the absolute value of the slope K of the first line AB of the four point broken line graph increases from west to east, showing the settlement slope of the east silty fine sand is more obvious than that of the west sandy cobble, and the absolute value of the slope K of the second straight line BC in the east is smaller than that in the west, indicating that the settlement influence range of the east is larger, the absolute value of the parameter bAB increases from west to east, indicating that the settlement value of the pile side soil of the silty clay and fine sand in the east is larger than that of the sandy pebble in the west. It is about 31% of the maximum settlement, 21% in the central region and only 16% in the western region. The research results will provide an important reference for surface deformation prediction and safety risk control of open cut foundation pit engineering in this region.
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表 1 北京不同区域各基坑地层物理力学指标
Table 1. Physical and mechanical indexes of foundation pit in different regions of Beijing
区域 岩层 天然密度/kPa 黏聚力/kPa 内摩擦角/（°） 压缩模量/MPa 泊松比 西部区域 填土 1.54～1.92 19.53～19.81 13.44～15.03 5.81～7.13 0.28～0.33 砂卵层 2.09～2.21 − 41.39～46.31 50.02～60.27 0.16～0.21 中粗砂 2.04～2.12 − 33.09～40.91 28.84～34.37 0.22～0.23 粉质黏土 1.89～2.01 25.60～46.72 16.23～23.54 6.84～10.46 0.29～0.35 中部区域 填土 1.59～1.89 19.66～19.74 13.89～15.34 5.67～7.45 0.24～0.31 中粗砂 2.07～2.10 − 32.87～40.24 28.97～34.22 0.22～0.23 粉质黏土 1.93～2.02 27.60～52.72 16.23～23.54 6.84～9.46 0.29～0.35 细中砂 2.03～2.06 − 32.20～36.84 27.63～35.42 0.23～0.24 东部区域 填土 1.59～1.89 19.66～19.74 13.89～15.34 5.67～7.45 0.24～0.31 粉细砂 1.92～2.18 − 25.32～31.08 18.36～28.91 0.23～0.25 粉质黏土 1.57～1.94 29.64～56.37 17.37～28.59 7.41～10.24 0.28～0.33 黏土 1.97～2.08 38.25～56.48 16.38～20.49 8.67～13.41 0.26～0.32 注：各基坑力学指标存在一些差异，表内统计数据为各基坑岩土体的力学指标数据范围。 
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表 2 西部基坑地表沉降实测数据计算表
Table 2. Calculations of the measured data of ground settlement of foundation pit in the west
测点
编号坐标
类别断面1 断面2 断面3 断面4 断面5 断面6 断面7 断面8 断面9 断面10 1# d1/H 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 δ1/δmax 0.14 0.27 0.21 0.17 0.06 0.11 0.10 0.20 0.17 0.17 2# d2/H 0.40 0.50 0.33 0.33 0.33 0.25 0.33 0.36 0.28 0.31 δ2/δmax 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 3# d3/H 1.00 1.00 0.56 0.94 1.00 0.50 1.00 0.71 0.56 1.00 δ3/δmax 0.42 0.45 0.44 0.34 0.28 0.26 0.29 0.23 0.26 0.43 4# d4/H 2.00 1.50 1.50 1.25 1.33 1.00 1.33 1.43 1.11 1.25 δ4/δmax 0.10 0.17 0.17 0.13 0.02 0.05 0.08 0.12 0.12 0.17 5# d5/H 3.00 3.00 1.67 1.88 − − 2.00 − 1.67 − δ5/δmax 0.01 0.00 0.03 0.02 − − 0.01 − 0.01 − 注：各基坑力学指标存在一些差异，表内统计数据为各基坑岩土体的力学指标数据范围。
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表 3 北京不同区域基坑四点折线图斜率K与截距b统计表
Table 3. Statistics of slope K and intercept b of four point broken line diagram of foundation pit in different areass of Beijing
区域 斜率Kij 断面1 断面2 断面3 断面4 断面5 断面6 断面7 断面8 断面9 断面10 西部
区域KAB −2.14 −1.46 −2.36 −2.49 −2.81 −3.58 −2.69 −2.25 −3.00 −2.65 KBC 0.56 0.83 0.71 0.95 0.98 1.27 0.92 0.82 1.05 0.89 KCD 0.09 0.07 1.12 0.17 0.98 1.27 0.11 − 0.19 − bAB −0.14 −0.27 −0.21 −0.17 −0.06 −0.11 −0.10 −0.20 −0.17 −0.17 bBC −1.23 −1.41 −1.24 −1.32 −1.33 −1.32 −1.31 −1.29 −1.29 −1.28 bCD −0.28 −0.21 −1.89 −0.35 −1.33 −1.32 −0.23 − −0.34 − 中部
区域KAB −4.19 −2.60 −3.04 −3.07 −2.86 −2.72 KBC 1.40 0.71 0.45 0.98 0.52 0.89 KCD 0.01 0.12 − 0.12 0.02 0.05 bAB −0.29 −0.22 −0.16 −0.15 −0.20 −0.25 bBC −1.30 −0.93 −1.12 −1.22 −1.17 −1.75 bCD −0.09 −0.28 − −0.27 −0.17 −0.17 东部
区域KAB −3.48 −2.74 −3.39 −3.76 −3.47 −3.16 −2.86 −2.93 KBC 1.23 0.83 0.58 0.98 1.27 1.07 0.86 0.89 KCD 0.34 0.13 0.91 0.20 − 0.16 0.18 − bAB −0.20 −0.34 −0.37 −0.27 −0.32 −0.38 −0.28 −0.29 bBC −1.62 −1.15 −1.15 −1.28 −1.42 −1.30 −1.29 −1.21 bCD −0.51 −0.27 −1.73 −0.35 − −0.28 −0.39 −
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[1] 张连泽, 张彬, 冯军, 等. 地铁车站明挖基坑开挖引起土体变形数值模拟研究[J]. 工程地质学报,2014,22(增刊 1):202 − 208. [ZHANG lianze, ZHANG Bin, FENG Jun, et al. Numerical simulation of soil deformation caused by open excavation of subway station[J]. Journal of engineering geology,2014,22(Sup 1):202 − 208. (in Chinese with English abstract)
[2] 王广国, 杜明芳, 侯学渊. 深基坑的大变形分析[J]. 岩石力学与工程学报,2000,19(4):509 − 512. [WANG Guangguo, DU Mingfang, HOU Xueyuan. Large deformation analysis for braced excavation[J]. Chinese Journal of Rock Mechanics and Engineering,2000,19(4):509 − 512. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2000.04.025
[3] 李淑, 张顶立, 房倩, 等. 北京地区深基坑墙体变形特性研究[J]. 岩石力学与工程学报,2012,31(11):2344 − 2353. [LI Shu, ZHANG Dingli, FANG Qian, et al. Research on characteristics of retaining wall deformation due to deep excavation in Beijing[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(11):2344 − 2353. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-6915.2012.11.024
[4] 肖潇, 李明广, 夏小和, 等. 基坑开挖对临近明挖暗埋隧道竖向变形的影响机理[J]. 上海交通大学学报,2018,52(11):1437 − 1443. [XIAO Xiao, LI Mingguang, XIA Xiaohe, et al. Mechanism analysis of influence of deep excavation on deformation of nearby cut-and-cover tunnel[J]. Journal of Shanghai Jiao Tong University,2018,52(11):1437 − 1443. (in Chinese with English abstract)
[5] 陈仁朋, 刘书伦, 孟凡衍, 等. 软黏土地层基坑开挖对旁侧隧道影响离心模型试验研究[J]. 岩土工程学报,2020,42(6):1132 − 1138. [CHEN Renpeng, LIU Shulun, MENG Fanyan, et al. Centrifuge modeling of excavation effects on a nearby tunnel in soft clay[J]. Chinese Journal of Geotechnical Engineering,2020,42(6):1132 − 1138. (in Chinese with English abstract)
[6] 王世君, 姚燕明, 汪健, 等. 软土地区地铁基坑浅层承压水控制及降压影响预测研究[J]. 都市快轨交通,2020,33(1):98 − 103. [WANG Shijun, YAO Yanming, WANG Jian, et al. Control of confined water and the calculation of the effect of falling groundwater levels of a subway foundation pit in soft soil[J]. Urban Rapid Rail Transit,2020,33(1):98 − 103. (in Chinese with English abstract) doi: 10.3969/j.issn.1672-6073.2020.01.017
[7] 骆祖江, 金鹏, 田开洋, 等. 深基坑降水与地面沉降模拟预测软件研制[J]. 江苏大学学报(自然科学版),2016,37(3):352 − 358. [LUO Zujiang, JIN Peng, TIAN Kaiyang, et al. Software development for simulating and predicting deep foundation pit dewatering and land subsidence[J]. Journal of Jiangsu University (Natural Science Edition),2016,37(3):352 − 358. (in Chinese with English abstract)
[8] 成峰, 张远芳, 万永祥, 等. 采用Gompertz模型预测深基坑周边地表沉降[J]. 地下空间与工程学报,2013,9(3):541 − 546. [CHENG Feng, ZHANG Yuanfang, WAN Yongxiang, et al. Subsidence prediction of deep foundation pit surrounding surface based on gompertz model[J]. Chinese Journal of Underground Space and Engineering,2013,9(3):541 − 546. (in Chinese with English abstract)
[9] 陈万鹏. 基坑开挖引起地表沉降的预测方法研究[D]. 南京: 南京工业大学, 2006.
CHEN Wanpeng. Study on prediction method of ground settlement caused by foundation pit excavation. Nanjing: Nanjing University of Technology, 2006. (in Chinese with English abstract)
[10] 张尚根, 袁正如. 软土深基坑开挖地表沉降分析[J]. 地下空间与工程学报,2013,9(增刊1):1753 − 1757. [ZHANG Shanggen, YUAN Zhengru. Analysis of ground settlement induced by excavation of deep foundation pit in soft soil[J]. Chinese Journal of Underground Space and Engineering,2013,9(Sup1):1753 − 1757. (in Chinese with English abstract)
[11] 王卫东, 徐中华. 预估深基坑开挖对周边建筑物影响的简化分析方法[J]. 岩土工程学报,2010,32(增刊1):32 − 38. [WANG Weidong, XU Zhonghua. Simplified analysis method for evaluating excavation-induced damage of adjacent buildings[J]. Chinese Journal of Geotechnical Engineering,2010,32(Sup1):32 − 38. (in Chinese with English abstract)
[12] 张建新, 周嘉宾, 吴东明. 超深逆作基坑围护结构变形分析[J]. 建筑结构,2012,42(4):121 − 123. [ZHANG Jianxin, ZHOU Jiabin, WU Dongming. Analysis of retaining structure deformation in super-deep foundation pit by top-down construction method[J]. Building Structure,2012,42(4):121 − 123. (in Chinese with English abstract)
[13] 孙曦源, 衡朝阳, 周智, 等. 厦门地铁车站基坑施工诱发地表沉降的经验预测方法研究[J]. 土木工程学报,2019,52(增刊2):132 − 138. [SUN Xiyuan, HENG Chaoyang, ZHOU Zhi, et al. An empirical method for predicting ground surface settlement induced by metro station pit in Xiamen[J]. China Civil Engineering Journal,2019,52(Sup2):132 − 138. (in Chinese with English abstract)
[14] 刘国彬, 王卫东. 基坑工程手册[M]. 2版. 北京: 中国建筑工业出版社, 2009.
LIU Guobin, WANG Weidong. Excavation engineering handbook[M]. 2nd ed. Beijing: China Architecture & Building Press, 2009.(in Chinese)
[15] 胡之锋, 陈健, 邱岳峰, 等. 一种黏土层中深基坑开挖地表沉降预测方法[J]. 长江科学院院报,2019,36(6):60 − 67. [HU Zhifeng, CHEN Jian, QIU Yuefeng, et al. A simplified method for predicting ground surface settlement induced by deep excavation of clay stratum[J]. Journal of Yangtze River Scientific Research Institute,2019,36(6):60 − 67. (in Chinese with English abstract) doi: 10.11988/ckyyb.20171282
[16] 吴锋波, 金淮, 朱少坤. 北京市轨道交通基坑工程地表变形特性[J]. 岩土力学,2016,37(4):1066 − 1074. [WU Fengbo, JIN Huai, ZHU Shaokun. Ground deformation characteristics of foundation pit related to the urban rail transit in Beijing[J]. Rock and Soil Mechanics,2016,37(4):1066 − 1074. (in Chinese with English abstract)
[17] 陈立国, 吴昊天, 陈晓斌, 等. 超载预压处理软土的次固结特征及沉降计算[J]. 水文地质工程地质,2021,48(1):138 − 145. [CHEN Liguo, WU Haotian, CHEN Xiaobin, et al. Secondary consolidation characteristics and settlement calculation of soft soil treated by overload preloading[J]. Hydrogeology & Engineering Geology,2021,48(1):138 − 145. (in Chinese with English abstract)
[18] 邹大鹏, 王珣. 北京地区山前冲洪积扇复杂地层盾构施工技术[J]. 城市轨道交通研究,2008,11(7):64 − 67. [ZOU Dapeng, WANG Xun. Shield construction technique on the complicated stratum of piedmont alluvial-pluvial fan in Beijing[J]. Urban Mass Transit,2008,11(7):64 − 67. (in Chinese with English abstract) doi: 10.3969/j.issn.1007-869X.2008.07.017
[19] 左建. 地质地貌学[M]. 2版. 北京: 中国水利水电出版社, 2007.
ZUO Jian. Geology and geomorphology[M]. 2nd ed. Beijing: China Water Power Press, 2007.(in Chinese)
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