Deformation characteristics of deep foundation pit with suspended waterproof curtain during excavation
-
摘要:
降水条件对基坑开挖的变形特性具有重要影响。为了研究悬挂式止水帷幕结合承压非完整井组成的墙井系统条件下基坑开挖过程中的变形问题，以某悬挂式止水帷幕深基坑为例，通过定义降水井和地表渗流边界条件建立了考虑分级降水和基坑开挖实际工况的三维流固耦合有限元数值分析模型，使用现场监测数据与数值模拟结果互相验证的方法研究了悬挂式止水帷幕情况下基坑开挖过程中地下连续墙变形和地表沉降的变化特征，对比分析了悬挂式止水帷幕和落底式止水帷幕条件下的地表沉降。结果表明：在不同分级降水情况下，降水深度初次达到场地第一承压水含水层降水期间产生的地下连续墙水平位移增量最大，地表沉降也主要在这一期间产生；悬挂式止水帷幕情况下的地表沉降最大值约为落底式止水帷幕的2.7倍，最大值位置距地下连续墙边缘的距离比落底式止水帷幕大0.85 m；地下连续墙水平位移峰值处，降水期间产生的位移占28%，地表沉降峰值处，降水期间产生的沉降占49%；使用悬挂式止水帷幕时，距地下连续墙边缘12倍开挖深度处，地表沉降与地表沉降峰值的比值为0.1、该距离比落底式止水帷幕大13 m左右。研究成果对确定深基坑降水方案、保证深基坑开挖施工安全具有一定的参考价值。
Abstract:Dewatering conditions have an important influence on the deformation characteristics of foundation pit excavation. In order to study the deformation problem during foundation pit excavation under the condition of a wall-well system consisting of suspended waterproof curtain combined with confined partially penetrating well, this study takes a deep foundation pit with suspended waterproof curtain as an example, uses the finite element numerical analysis to establish a 3D fluid-solid interaction model, and takes into account the actual working conditions of graded dewatering during the pit excavation by defining the seepage boundary conditions of the dewatering well and the surface. The monitoring data and simulation results are combined to explore the variation features of underground diaphragm wall deformation and surface settlement with suspended waterproof curtain, and the surface settlement under the conditions of suspended waterproof curtain and drop waterproof curtain is further compared and analyzed. The results show that in dewatering process of the foundation pit at all levels, the horizontal displacement increment of the underground diaphragm wall is the greatest with the most of the surface subsidence as the dewatering depth reaches the first confined aquifer. The maximum surface settlement generated by foundation pit with suspended waterproof curtain is about 2.7 times that with drop waterproof curtain, with the greater 0.8 m of the maximum surface settlement location. At the peak of horizontal displacement of underground diaphragm wall, the displacement during dewatering accounts for 28%, and at the peak of surface settlement, the settlement during dewatering accounts for 49%. When the suspended waterproof curtain is used at 12 times the excavation depth from the edge of the diaphragm wall, the ratio of surface settlement to the peak of surface settlement is 0.1, which is about 13 m greater than that of the drop waterproof curtain. The research results are of a reference value for determining the deep foundation pit dewatering scheme and ensuring the safety of deep foundation pit excavation construction.
-
-
表 1 研究区土层性质
Table 1. Characteristics of the soil layers in the study area
土层特征 土层名称 含水层名称 厚度/m ①3 素填土 潜水层 2.63 ③2 粉质黏土 弱透水层 4.30 ④1 粉质黏土 弱透水层 4.50 ④2 粉砂夹粉土 承压水层 6.30 ⑤1 粉质黏土夹粉砂 弱透水层 6.20 ⑤2 粉砂夹粉质黏土 承压水层 5.40 ⑦1 粉质黏土 弱透水层 5.67 
下载: 导出CSV
表 2 各土层物理力学性质参数
Table 2. Physical and mechanical parameters of the soil layers
各土层性质 ρ/（g∙cm−3） λ Μ e1 κ KV/（m∙d−1） KH/（m∙d−1） υ ①3 1.90 0.077 0 0.570 0.811 0.009 0 3.89×10−3 5.84×10−3 0.33 ③2 1.94 0.055 3 0.979 0.822 0.006 5 5.62×10−3 8.43×10−3 0.33 ④1 1.89 0.044 5 0.979 0.696 0.005 2 8.21×10−3 1.23×10−2 0.33 ④2 1.91 0.029 3 1.202 0.640 0.003 4 1.73 2.60 0.23 ⑤1 1.89 0.032 0 0.900 0.611 0.003 7 5.18×10−2 7.77×10−2 0.33 ⑤2 1.94 0.019 1 1.382 0.585 0.002 2 2.59 3.89 0.23 ⑦1 1.90 0.030 5 0.900 0.676 0.003 5 5.00×10−3 7.50×10-3 0.38 注：ρ为密度；λ为土体压缩指数；Μ为土体应力比；e1为压力为1 kPa时土体的孔隙比；κ为土体回弹指数；KV为土体竖直渗透系数； KH为土体水平渗透系数；υ为泊松比。
下载: 导出CSV
表 3 围护结构及降水井材料参数
Table 3. Material parameters of the retaining structure and dewatering well
参数 ρ/（g∙cm−3） E/MPa υ 地下连续墙 2.42 31 500 0.20 混凝土支撑 2.36 30 000 0.20 钢支撑 7.85 200 000 0.20 降水井 7.85 210 000 0.20 注：E为弹性模量。
下载: 导出CSV
-
[1] 董崇泽,孙智杰. 硬岩水文地质参数井同径止水与分层抽水试验研究[J]. 水文地质工程地质,2022,49(4):55 − 61. [DONG Chongze,SUN Zhijie. Experimental investigation on same diameter sealing and stratified pumping of hard rock hydrogeological parameter well[J]. Hydrogeology & Engineering Geology,2022,49(4):55 − 61. (in Chinese with English abstract)
DONG Chongze, SUN Zhijie. Experimental investigation on same diameter sealing and stratified pumping of hard rock hydrogeological parameter well[J]. Hydrogeology & Engineering Geology, 2022, 49（4）: 55-61. （in Chinese with English abstract）
[2] 邓祺文,陈刚,郑可,等. 基于广义径向流模型的非均质孔隙含水层井流试验分析[J]. 水文地质工程地质,2022,49(2):17 − 23. [DENG Qiwen,CHEN Gang,ZHENG Ke,et al. Pumping tests analyses of a heterogeneous pore aquifer based on the Generalized Radial Flow model[J]. Hydrogeology & Engineering Geology,2022,49(2):17 − 23. (in Chinese with English abstract)
DENG Qiwen, CHEN Gang, ZHENG Ke, et al. Pumping tests analyses of a heterogeneous pore aquifer based on the Generalized Radial Flow model[J]. Hydrogeology & Engineering Geology, 2022, 49（2）: 17-23. （in Chinese with English abstract）
[3] 周火垚, 王华钦, 张维泉. 悬挂式止水在基坑工程中的应用[J]. 岩土工程学报, 2012, 34（增刊1）: 470 – 473
ZHOU Huoyao, WANG Huaqin, ZHANG Weiquan. Application of pensile impervious curtain to excavations[J]. Chinese Journal of Geotechnical Engineering, 2012, 34（Sup 1）: 470 – 473. （in Chinese with English abstract）
[4] 刘胜利,蒋盛钢,曹成勇. 强透水砂卵地层深基坑地下水控制方案比选与优化设计[J]. 铁道科学与工程学报,2018,15(12):3189 − 3197. [LIU Shengli,JIANG Shenggang,CAO Chengyong. Comparison and optimization of alternatives to groundwater control for a deep excavation in highly permeable sand and gravel[J]. Journal of Railway Science and Engineering,2018,15(12):3189 − 3197. (in Chinese with English abstract)
LIU Shengli, JIANG Shenggang, CAO Chengyong. Comparison and optimization of alternatives to groundwater control for a deep excavation in highly permeable sand and gravel[J]. Journal of Railway Science and Engineering, 2018, 15（12）: 3189-3197. （in Chinese with English abstract）
[5] 李方明,陈国兴,刘雪珠. 悬挂式帷幕地铁深基坑变形特性研究[J]. 岩土工程学报,2018,40(12):2182 − 2190. [LI Fangming,CHEN Guoxing,LIU Xuezhu. Deformation characteristics of suspended curtain deep foundation pit of metro lines[J]. Chinese Journal of Geotechnical Engineering,2018,40(12):2182 − 2190. (in Chinese with English abstract)
LI Fangming, CHEN Guoxing, LIU Xuezhu. Deformation characteristics of suspended curtain deep foundation pit of metro lines[J]. Chinese Journal of Geotechnical Engineering, 2018, 40（12）: 2182-2190. （in Chinese with English abstract）
[6] 彭祎, 成建梅, 马郧, 等. 基于改进阻力系数法的悬挂式帷幕基坑渗流计算[J]. 地质科技通报, 2021, 40（4）: 179 − 186.
PENG Yi, CHENG Jianmei, MA Yun, et al. Seepage calculation of foundation with suspended curtain based on improved resistance coefficient method[J]. Bulletin of Geological Science and Technology, 2021, 40（4）: 179 − 186. （in Chinese with English abstract）
[7] 孙琳, 李云安, 鲁贤成, 等. 基坑开挖及降水对周边地铁隧道变形的影响分析[J]. 安全与环境工程, 2020, 27（4）: 207 − 214.
SUN Lin, LI Yun’an, LU Xiancheng, et al. Influence of foundation pit excavation and dewatering on deformation of surrounding subway tunnels[J]. Safety and Environmental Engineering, 2020, 27（4）: 207 − 214. （in Chinese with English abstract）
[8] LEUNG E H Y, NG C W W. Wall and ground movements associated with deep excavations supported by cast in situ wall in mixed ground conditions[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2007, 132（2）: 129 – 143.
[9] 张军, 冯佳蕊, 翟少磊. 洞庭湖大桥锚定基坑降水及对地连墙影响分析[J]. 地下空间与工程学报, 2018, 14（增刊1）: 256 − 262
ZHANG Jun, FENG Jiarui, ZHAI Shaolei. Dewatering of anchored foundation pit of Dongting Lake bridge and its influence on diaphragm wall[J]. Chinese Journal of Underground Space and Engineering, 2018, 14（Sup 1）: 256 − 262. （in Chinese with English abstract）
[10] LIU G B,NG C W W,WANG Z W. Observed performance of a deep multistrutted excavation in Shanghai soft clays[J]. Journal of Geotechnical and Geoenvironmental Engineering,2005,131(8):1004 − 1013. doi: 10.1061/(ASCE)1090-0241(2005)131:8(1004)
[11] ROBERTS T O L,ROSCOE H,POWRIE W,et al. Controlling clay pore pressures for cut-and-cover tunnelling[J]. Proceedings of the Institution of Civil Engineers-Geotechnical Engineering,2007,160(4):227 − 236. doi: 10.1680/geng.2007.160.4.227
[12] 江杰,杨杉楠,胡盛斌,等. 预降水过程中止水帷幕缺陷对基坑变形的影响[J]. 广西大学学报(自然科学版),2020,45(5):996 − 1005. [JIANG Jie,YANG Shannan,HU Shengbin,et al. Influence of waterproof curtain defect on foundation pit deformation in pre-dewatering process[J]. Journal of Guangxi University (Natural Science Edition),2020,45(5):996 − 1005. (in Chinese with English abstract)
JIANG Jie, YANG Shannan, HU Shengbin, et al. Influence of waterproof curtain defect on foundation pit deformation in pre-dewatering process[J]. Journal of Guangxi University （Natural Science Edition）, 2020, 45（5）: 996-1005. （in Chinese with English abstract）
[13] 何山. 宁波地铁3号线仇毕站基坑工程地下水控制数值分析[J]. 施工技术, 2017, 46（增刊2）: 231 − 234
HE Shan. Numerical analysis of ground water control in qiubi station of Ningbo metro line 3[J]. Construction Technology, 2017, 46（Sup 2）: 231 − 234. （in Chinese with English abstract）
[14] 胡长明,林成. 黄土深基坑潜水区降水诱发地面沉降的简化算法[J]. 中国地质灾害与防治学报,2021,32(3):76 − 83. [HU Changming,LIN Cheng. Simplified calculation of settlement due to dewatering of phreatic aquifer in loess area[J]. The Chinese Journal of Geological Hazard and Control,2021,32(3):76 − 83. (in Chinese with English abstract)
HU Changming, LIN Cheng. Simplified calculation of settlement due to dewatering of phreatic aquifer in loess area[J]. The Chinese Journal of Geological Hazard and Control, 2021, 32（3）: 76-83. （in Chinese with English abstract）
[15] 娄平,赵星,汤卓,等. 朝阳站富水砂卵石层施工动态降水控制技术研究[J]. 铁道科学与工程学报,2019,16(2):457 − 463. [LOU Ping,ZHAO Xing,TANG Zhuo,et al. Study on dynamic dewatering control technology for water-rich sandy gravel layer in Chaoyang Station[J]. Journal of Railway Science and Engineering,2019,16(2):457 − 463. (in Chinese with English abstract)
LOU Ping, ZHAO Xing, TANG Zhuo, et al. Study on dynamic dewatering control technology for water-rich sandy gravel layer in Chaoyang Station[J]. Journal of Railway Science and Engineering, 2019, 16（2）: 457-463. （in Chinese with English abstract）
[16] KHOSRAVI M,KHOSRAVI M H,GHOREISHI NAJAFABADI S H. Determining the portion of dewatering-induced settlement in excavation pit projects[J]. International Journal of Geotechnical Engineering,2021,15(5):563 − 573. doi: 10.1080/19386362.2018.1467858
[17] 张建全,张克利,程贵方. 北京不同区域明挖基坑地表沉降变形特征研究[J]. 水文地质工程地质,2021,48(6):131 − 139. [ZHANG Jianquan,ZHANG Keli,CHENG Guifang. Characteristics of surface settlement and deformation of open cut foundation pit in different areas of Beijing[J]. Hydrogeology & Engineering Geology,2021,48(6):131 − 139. (in Chinese with English abstract)
ZHANG Jianquan, ZHANG Keli, CHENG Guifang. Characteristics of surface settlement and deformation of open cut foundation pit in different areas of Beijing[J]. Hydrogeology & Engineering Geology, 2021, 48（6）: 131-139. （in Chinese with English abstract）
[18] 秦胜伍,张延庆,张领帅,等. 基于Stacking模型融合的深基坑地面沉降预测[J]. 吉林大学学报(地球科学版),2021,51(5):1316 − 1323. [QIN Shengwu,ZHANG Yanqing,ZHANG Lingshuai,et al. Prediction of ground settlement around deep foundation pit based on stacking model fusion[J]. Journal of Jilin University (Earth Science Edition),2021,51(5):1316 − 1323. (in Chinese with English abstract)
QIN Shengwu, ZHANG Yanqing, ZHANG Lingshuai, et al. Prediction of ground settlement around deep foundation pit based on stacking model fusion[J]. Journal of Jilin University (Earth Science Edition), 2021, 51(5): 1316-1323.（in Chinese with English abstract）
[19] ZHENG Gang,ZENG Chaofeng,DIAO Yu,et al. Test and numerical research on wall deflections induced by pre-excavation dewatering[J]. Computers and Geotechnics,2014,62(8):244 − 256.
[20] 何绍衡,夏唐代,李连祥,等. 地下水渗流对悬挂式止水帷幕基坑变形影响[J]. 浙江大学学报(工学版),2019,53(4):713 − 723. [HE Shaoheng,XIA Tangdai,LI Lianxiang,et al. Influence of groundwater seepage on deformation of foundation pits with suspended impervious curtains[J]. Journal of Zhejiang University (Engineering Science),2019,53(4):713 − 723. (in Chinese with English abstract)
HE Shaoheng, XIA Tangdai, LI Lianxiang, et al. Influence of groundwater seepage on deformation of foundation pits with suspended impervious curtains[J]. Journal of Zhejiang University （Engineering Science）, 2019, 53（4）: 713-723. （in Chinese with English abstract）
[21] 郑刚, 赵悦镔, 程雪松, 等. 复杂地层中基坑降水引发的水位及沉降分析与控制对策[J]. 土木工程学报, 2019, 52（增刊1）: 135 − 142
ZHENG Gang, ZHAO Yuebin, CHENG Xuesong, et al. Strategy and analysis of the settlement and deformation caused by dewatering under complicated geological condition[J]. China Civil Engineering Journal, 2019, 52（Sup 1）: 135 − 142. （in Chinese with English abstract）
[22] 李瑛,陈东,刘兴旺,等. 悬挂式止水帷幕深基坑减压降水的简化计算方法[J]. 岩土力学,2021,42(3):826 − 832. [LI Ying,CHEN Dong,LIU Xingwang,et al. Simplified calculation method of decompression dewatering for deep excavation with suspended waterproof curtain[J]. Rock and Soil Mechanics,2021,42(3):826 − 832. (in Chinese with English abstract)
LI Ying, CHEN Dong, LIU Xingwang, et al. Simplified calculation method of decompression dewatering for deep excavation with suspended waterproof curtain[J]. Rock and Soil Mechanics, 2021, 42（3）: 826-832. （in Chinese with English abstract）
[23] 李又云, 杨立新, 刘伟, 等. 悬挂式止水帷幕深基坑分级降水开挖变形特性[J]. 科学技术与工程, 2021, 21（5）: 1995 − 2001.
LI Youyun, YANG Lixin, LIU Wei, et al. The deformation characteristics of deep foundation pit with suspended curtain in the process of graded dewatering excavation[J]. Science Technology and Engineering, 2021, 21（5）: 1995 − 2001. （in Chinese with English abstract）
[24] LI Fangming,CHEN Guoxing. Study of ground surface settlement of foundation pit with suspended waterproof curtain in Yangtze River floodplain[J]. Tunnel Construction,2018,38(1):33 − 40.
[25] 骆祖江,成磊,张兴旺,等. 悬挂式止水帷幕深基坑降水方案模拟优化[J]. 吉林大学学报(地球科学版),2022,52(6):1946 − 1956. [LUO Zujiang,CHENG Lei,ZHANG Xingwang,et al. Simulation and optimization of dewatering scheme for deep foundation pit with suspended waterproof curtain[J]. Journal of Jilin University (Earth Science Edition),2022,52(6):1946 − 1956. (in Chinese with English abstract)
LUO Zujiang, CHENG Lei, ZHANG Xingwang, et al. Simulation and optimization of dewatering scheme for deep foundation pit with suspended waterproof curtain[J]. Journal of Jilin University (Earth Science Edition), 2022, 52(6): 1946-1956.（in Chinese with English abstract）
[26] LIU Wenbin. Impact of the excavation and dewatering of the foundation pit on the stability of the plug-in steel cylinder[J]. IOP Conference Series:Earth and Environmental Science,2021,651(3):032032. doi: 10.1088/1755-1315/651/3/032032
[27] CHEN Xiaopeng,LU Qingrui,JIANG Xiaoyi,et al. The influence of steel bracing on the stability of foundation pit excavation under dewatering condition[J]. IOP Conference Series:Earth and Environmental Science,2021,719(3):032054. doi: 10.1088/1755-1315/719/3/032054
[28] SHI Jinjiang, WU Bo, LIU Yi, et al. Analysis of the influence of groundwater seepage on the deformation of deep foundation pit with suspended impervious curtain[J]. Advances in Mechanical Engineering, 2022, 14（3）: 168781322210851.
[29] 郑刚,曾超峰. 基坑开挖前潜水降水引起的地下连续墙侧移研究[J]. 岩土工程学报,2013,35(12):2153 − 2163. [ZHENG Gang,ZENG Chaofeng. Lateral displacement of diaphragm wall by dewatering of phreatic water before excavation[J]. Chinese Journal of Geotechnical Engineering,2013,35(12):2153 − 2163. (in Chinese with English abstract)
ZHENG Gang, ZENG Chaofeng. Lateral displacement of diaphragm wall by dewatering of phreatic water before excavation[J]. Chinese Journal of Geotechnical Engineering, 2013, 35（12）: 2153-2163. （in Chinese with English abstract）
[30] 曾超峰,薛秀丽,郑刚. 软土地基渗透性条件对基坑预降水过程中支护墙侧移的影响研究[J]. 岩土力学,2017,38(10):3039 − 3047. [ZENG Chaofeng,XUE Xiuli,ZHENG Gang. Effect of soil permeability on wall deflection during pre-excavation dewatering in soft ground[J]. Rock and Soil Mechanics,2017,38(10):3039 − 3047. (in Chinese with English abstract) doi: 10.16285/j.rsm.2017.10.033
ZENG Chaofeng, XUE Xiuli, ZHENG Gang. Effect of soil permeability on wall deflection during pre-excavation dewatering in soft ground[J]. Rock and Soil Mechanics, 2017, 38（10）: 3039-3047. （in Chinese with English abstract） doi: 10.16285/j.rsm.2017.10.033
-
图(12)
表(3)
计量
- 文章访问数: 1149
- PDF下载数: 78
- 施引文献: 0