Optimum design of front-braced grouting steel pipe system in the foundation pit engineering in Shanghai
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摘要: 通过对比分析上海地区不同地质条件下前撑式注浆钢管围护体系的规范计算和实测变形特性，提出了提高承载力和围护桩变形控制的优化设计方法及措施，并通过数值模拟进行了验证。研究结果表明：（1）对于基坑底和前撑桩底土质均不佳的基坑工程，围护体系实测变形显著大于规范计算值，前撑桩最优水平夹角为45°，施工过程中采用分区挖土，增设预制垫层等方式，可以减小围护桩10%左右的总变形，通过减小单次开挖面积可以进一步控制围护桩变形；（2）对于基坑坑底土质不佳，前撑桩底土质较好的基坑工程，围护桩实测变形稍大于规范计算值，可以加大前撑桩的水平夹角至50°～55°，在水平承载力不变的前提下可减短前撑桩桩长，提升经济性，并通过分区挖土及设置垫层的方式控制变形，同时需关注围护桩与围檩间的抗剪设计；（3）对于基坑坑底及前撑桩底土质均较好的基坑工程，围护桩实测变形与规范计算值较为接近，可以减小前撑桩水平夹角至30°～35°，在水平承载力不变的前提下减短前撑桩长度，控制围护桩桩顶变形，同时提升经济性。Abstract: Through comparative analysis of the code-calculated and measured deformation characteristics of the front-braced grouting steel pipe system under different geological conditions in Shanghai, optimized design methods and measures for improving bearing capacity and controlling the deformation of retaining piles are proposed and verified by numerical simulation. The results show that: (1) For foundation pits with poor soil conditions at both the pit bottom and the front-braced pile bottom, the measured deformation of the retaining system is significantly larger than the code-calculated value. The optimal horizontal angle of the front-braced piles is 45°. Zoned excavation and the addition of precast cushions during construction can reduce the total deformation of retaining piles by approximately 10%. Further deformation control can be achieved by reducing the single excavation area. (2) For foundation pits with poor soil at the pit bottom but good soil at the front-braced pile bottom, the measured deformation of retaining piles is slightly larger than the code-calculated value. The horizontal angle of front-braced piles can be increased to 50°~55°, which shortens the pile length while maintaining the same horizontal bearing capacity, thus improving economic efficiency. Deformation can be controlled via zoned excavation and cushion installation, and attention should be paid to the shear design between retaining piles and wales. (3) For foundation pits with good soil at both the pit bottom and the front-braced pile bottom, the measured deformation of retaining piles is close to the code-calculated value. The horizontal angle of front-braced piles can be reduced to 30°~35°, which shortens the pile length under constant horizontal bearing capacity, controls the deformation of the pile top, and also improves economic efficiency.
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Key words:
- Shanghai district /
- front-braced grouting steel pipe /
- foundation pit /
- optimum design
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图 1 前撑式注浆钢管围护体系剖面示意图
Figure 1. Generalized section of prestressed grouting steel pipe system
图 2 规范计算与实测围护桩侧向位移对比曲线
Figure 2. Correlation curve of standard calculation and measured lateral displacement of retaining pile
图 3 工程一前撑桩承载力优化对比图
Figure 3. Comparison diagram of optimization bearing capacity for the prestressed grouting steel pipe system in Project One
图 4 工程二前撑桩承载力优化对比图
Figure 4. Comparison diagram of optimization bearing capacity for the prestressed grouting steel pipe system in Project Two
图 5 工程三前撑桩承载力优化对比图
Figure 5. Comparison diagram of optimization bearing capacity for the prestressed grouting steel pipe system in Project Three
图 6 围护体变形控制优化措施示意图
Figure 6. Schematic diagram of the deformation controlling measures of the foundation pit retaining pile
表 1 工程概况及土层物理力学性质指标
Table 1. Project profile and physical and mechanical properties index of soil
工程概况 土层序号 土层名称 天然重度
γ/ （kN·m−3）黏聚力
ccq/kPa内摩擦角
φcq/（°）平均层
厚/m比贯入
阻力Ps/MPa桩侧极限摩
阻力标准值
fs/kPa桩端极限端
阻力标准值
fp/kPa工程一：面积50122 m2，挖深6.65 m，围护结构：SMW工法桩（ϕ850@600 mm三轴搅拌桩内插H700×300 mm型钢）+前撑式注浆钢管（ϕ377×10 mm，倾角45°，L=26 m@3600 mm，端部9 m注浆） ① 填土 18 10 10.0 1.82 ② 粉质黏土 18.9 22 21.5 1.73 0.73 15 ③（坑底） 淤泥质粉质黏土 17.8 16 16.0 4.10 0.47 15 ③夹 砂质粉土 18.5 6 29.5 1.96 1.30 15 ④ 淤泥质黏土 16.9 13 12.0 8.94 0.60 20 ⑤1（桩底） 黏土 17.5 17 15.0 9.18 0.93 35 400 工程二：面积29217 m2，挖深5.75 m，围护结构：SMW工法（2ϕ700@1000 mm双轴搅拌桩内插H500×300 mm型钢）+前撑式注浆钢管（ϕ377×10 mm，倾角45°，L=27 m@4000 mm，端部9 m注浆） ① 填土 18 10 10.0 4.53 ③2（坑底） 砂质粉土 18.5 2 30.5 2.19 1.87 15 ③3 淤泥质粉质黏土 17.6 12 16.5 3.49 0.48 15 ④ 淤泥质黏土 16.8 11 11.0 6.03 0.60 25 ⑤1 黏土 17.5 16 13.0 2.93 0.76 30 ⑤2-1（桩底） 粉砂 18.9 4 33.0 3.70 4.91 55 1250 工程三：面积21648 m2，挖深4.75 m，围护结构：SMW工法（ϕ650@450 mm三轴搅拌桩内插H500×300 mm型钢）+前撑式注浆钢管（ϕ377×10 mm，倾角45°，L=28 m@4500 mm，全长注浆） ①1 填土 18 10 10.0 1.99 ①2 淤泥 18 10 10.0 1.28 ③（坑底） 淤泥质粉质黏土 17.3 12 11.5 1.83 0.43 15 ⑥1 粉质黏土 19.3 38 15.5 4.20 2.42 40 750 ⑥3-1（桩底） 粉质黏土 18.5 27 15.0 10.34 4.04 35 500 
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表 2 模拟工况
Table 2. Simulated conditions
工程类别 模拟方案 方案内容 工程一 方案一 钢管26 m，倾角45°，原岛式开挖 方案二 钢管26 m，倾角45°，优化后开挖 工程二 方案一 钢管26 m，倾角45°，原岛式开挖 方案二 钢管25 m，倾角52°，原岛式开挖 方案三 钢管25 m，倾角52°，优化后开挖 工程三 方案一 钢管26 m，倾角45°，原岛式开挖 方案二 钢管23 m，倾角35°，原岛式开挖 方案三 钢管23 m，倾角35°，优化后开挖 注：基坑挖深6.65 m，围护结构为SMW工法桩（ϕ850@600 mm三轴搅拌桩内插H700×300 mm型钢）+前撑式注浆钢管（ϕ377 × 10 mm，间距3.6 m）。方案二和方案三前撑桩角度和长度调整后与方案一承载力水平分力基本一致。
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表 3 优化措施模拟结果对比表
Table 3. Comparison table of simulation results of optimization measures
工程类别 模拟方案 围护体侧向
最大位移/mm结论 工程一 方案一 56.9 方案二 51.2 与方案一相比，造价相当，
变形减小10%工程二 方案一 49.7 方案二 51.2 与方案一相比，造价节约4%，
变形增大3%方案三 47.1 与方案一相比，造价节约4%，
变形减小5%工程三 方案一 8.9 方案二 6.9 与方案一相比，造价节约11.5%，
变形减小22.5%方案三 6.4 与方案一相比，造价节约11.5%，
变形减小28%
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[1] 上海市建设协会. 自稳式基坑支护结构技术标准: T/SCDA 012—2021[S]. 上海: 上海市建设协会, 2021. (Shanghai Construction & Development Association. Technical standard for self-stable retaining structure of foundation excavation: T/SCDA 012—2021[S]. Shanghai: Shanghai Construction & Development Association, 2021. (in Chinese)Shanghai Construction & Development Association. Technical standard for self-stable retaining structure of foundation excavation: T/SCDA 012—2021[S]. Shanghai: Shanghai Construction & Development Association, 2021. (in Chinese) [2] 顾国荣, 杨石飞, 许 杰, 等. 一种可回收直立式钢管前撑围护结构及其应用方法: CN103410156B[P]. 2016-01-27. (GU G R, YANG S F, XU J, et al. Recyclable vertical steel tube front supporting envelop enclosure and applying method thereof: CN103410156B[P]. 2016-01-27. (in Chinese)GU G R, YANG S F, XU J, et al. Recyclable vertical steel tube front supporting envelop enclosure and applying method thereof: CN103410156B[P]. 2016-01-27. (in Chinese) [3] 陆秋平, 周 吉, 陆陈华. 前撑式注浆钢管桩在砂质粉土层中的应用[J]. 建筑施工, 2019, 41(10): 1792-1794. (LU Q P, ZHOU J, LU C H. Application of front-braced grouting steel pipe pile in sandy silt layer[J]. Building Construction, 2019, 41(10): 1792-1794. (in Chinese) doi: 10.14144/j.cnki.jzsg.2019.10.005LU Q P, ZHOU J, LU C H. Application of front-braced grouting steel pipe pile in sandy silt layer[J]. Building Construction, 2019, 41（10）: 1792-1794. (in Chinese) doi: 10.14144/j.cnki.jzsg.2019.10.005 [4] 董林兵. 前撑注浆钢管桩在大面积深基坑工程中的应用[J]. 建筑施工, 2020, 42(7): 1126-1127,1137. (DONG L B. Application of steel pipe pile with front support grouting in large area deep foundation pit engineering[J]. Building Construction, 2020, 42(7): 1126-1127,1137. (in Chinese) doi: 10.14144/j.cnki.jzsg.2020.07.005DONG L B. Application of steel pipe pile with front support grouting in large area deep foundation pit engineering[J]. Building Construction, 2020, 42（7）: 1126-1127,1137. (in Chinese) doi: 10.14144/j.cnki.jzsg.2020.07.005 [5] 郑先元, 张 志. 前撑式注浆钢管斜撑体系在基坑工程中的应用分析[J]. 工程质量, 2019, 37(1): 69-72,86. (ZHENG X Y, ZHANG Z. Analysis of application of the advanced grouting steel pipe diagonal brace system in deep foundation excavation engineering[J]. Construction Quality, 2019, 37(1): 69-72,86. (in Chinese) doi: 10.3969/j.issn.1671-3702.2019.01.016ZHENG X Y, ZHANG Z. Analysis of application of the advanced grouting steel pipe diagonal brace system in deep foundation excavation engineering[J]. Construction Quality, 2019, 37（1）: 69-72,86. (in Chinese) doi: 10.3969/j.issn.1671-3702.2019.01.016 [6] 惠彬永. 前撑式注浆钢管支撑在基坑围护中的应用与研究[J]. 建筑施工, 2018, 40(11): 1868-1870. (HUI B Y. Application and research on supporting of front supported type grouting steel pipe in foundation pit support[J]. Building Construction, 2018, 40(11): 1868-1870. (in Chinese) doi: 10.14144/j.cnki.jzsg.2018.11.005HUI B Y. Application and research on supporting of front supported type grouting steel pipe in foundation pit support[J]. Building Construction, 2018, 40（11）: 1868-1870. (in Chinese) doi: 10.14144/j.cnki.jzsg.2018.11.005 [7] 施春锋. 前撑式注浆管在深基坑工程中的应用[J]. 建筑施工, 2022, 44(6): 1157-1159. (SHI C F. Application of front support grouting pipe in deep foundation pit engineering[J]. Building Construction, 2022, 44(6): 1157-1159. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.06.003SHI C F. Application of front support grouting pipe in deep foundation pit engineering[J]. Building Construction, 2022, 44（6）: 1157-1159. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.06.003 [8] 徐 枫. 自稳式注浆钢管前撑技术在深大基坑中的应用[J]. 工程勘察, 2024, 52(11): 32-38. (XU F. Application of self stabilizing grouting steel pipe front support technique in deep and large excavations[J]. Geotechnical Investigation & Surveying, 2024, 52(11): 32-38. (in Chinese)XU F. Application of self stabilizing grouting steel pipe front support technique in deep and large excavations[J]. Geotechnical Investigation & Surveying, 2024, 52（11）: 32-38. (in Chinese) [9] 魏建华, 韩鹏飞, 孔令荣,等 . 双排桩门架结合前撑注浆钢管支护结构在软土深基坑工程中的应用[J]. 地基处理, 2025, 7(3): 303-310. (WEI J H, HAN P F , KONG L R, et al. Application of double-row pile gantry combined with front-supported grouted steel pipe retaining structure in soft soil deep excavation[J]. Journal of Ground Improvement, 2025, 7(3): 303-310. (in Chinese)WEI J H, HAN P F , KONG L R, et al. Application of double-row pile gantry combined with front-supported grouted steel pipe retaining structure in soft soil deep excavation[J]. Journal of Ground Improvement, 2025, 7（3）: 303-310. [10] 窦红瑞. 自稳式支护技术在基坑工程中的应用[J]. 地基处理, 2025, 7(1): 90-100. (DOU H R. Application of self-stabilizing support technology in foundation pit engineering[J]. Journal of Ground Improvement, 2025, 7(1): 90-100. (in Chinese)DOU H R. Application of self-stabilizing support technology in foundation pit engineering[J]. Journal of Ground Improvement, 2025, 7（1）: 90-100. (in Chinese) [11] 海明雷, 魏建华. 前撑注浆钢管在某超大软土基坑中的应用[J]. 工程勘察, 2024, 52(3): 24-28. (HAI M L, WEI J H. Application of front-braced grouting steel pipe support in a super large deep excavation in soft ground[J]. Geotechnical Investigation & Surveying, 2024, 52(3): 24-28. (in Chinese)HAI M L, WEI J H. Application of front-braced grouting steel pipe support in a super large deep excavation in soft ground[J]. Geotechnical Investigation & Surveying, 2024, 52（3）: 24-28. (in Chinese) [12] 李 明. 前撑式注浆钢管桩在软土地区基坑工程中的应用[J]. 建筑施工, 2025, 45(5): 849-851. (LI M. Application of front-supported grouting steel pipe pile in foundation pit engineering in soft soil area[J]. Building Constrction, 2025, 45(5): 849-851. (in Chinese) doi: 10.14144/j.cnki.jzsg.2023.05.007LI M. Application of front-supported grouting steel pipe pile in foundation pit engineering in soft soil area[J]. Building Constrction, 2025, 45（5）: 849-851. doi: 10.14144/j.cnki.jzsg.2023.05.007 [13] 张荣文. 前撑式抗压注浆钢管支撑在基坑支护中的应用[J]. 建筑科技, 2019, 3(3): 128-130. (ZHANG R W. Application of pressure grounting front support in foundation construction[J]. Building Technology, 2019, 3(3): 128-130. (in Chinese) doi: 10.3969/j.issn.1007-046X.2019.03.039ZHANG R W. Application of pressure grounting front support in foundation construction[J]. Building Technology, 2019, 3（3）: 128-130. (in Chinese) doi: 10.3969/j.issn.1007-046X.2019.03.039 [14] 倪浩群. 前撑注浆钢管在软土基坑中的应用[J]. 建筑科技, 2025, 9(3): 80-82,96. (NI H Q. Application of front-bracing grouting steel pipes in soft soil foundation pits[J]. Building Technology, 2025, 9(3): 80-82,96. (in Chinese) doi: 10.3969/j.issn.1007-046X.2025.03.022NI H Q. Application of front-bracing grouting steel pipes in soft soil foundation pits[J]. Building Technology, 2025, 9（3）: 80-82,96. (in Chinese) doi: 10.3969/j.issn.1007-046X.2025.03.022 [15] 霍红伟, 潘昌盛, 蓬金高, 等. 基于前撑注浆钢管支撑体系的基坑施工效率提升研究[J]. 建筑施工, 2023, 45(11): 2157-2159. (HUO H W, PAN C S, PENG J G, et al. Research on improvement of foundation pit construction efficiency based on front support grouting steel pipe support system[J]. Building Construction, 2023, 45(11): 2157-2159. (in Chinese) doi: 10.14144/j.cnki.jzsg.2023.11.001HUO H W, PAN C S, PENG J G, et al. Research on improvement of foundation pit construction efficiency based on front support grouting steel pipe support system[J]. Building Construction, 2023, 45（11）: 2157-2159. (in Chinese) doi: 10.14144/j.cnki.jzsg.2023.11.001 [16] 陈学成. 前撑注浆钢管支护体系在基坑工程中的应用[J]. 广东土木与建筑, 2021, 28(5): 62-64,111. (CHEN X C. Analysis of front-braced grouting steel pipe pile in deep foundation excavation engineering[J]. Guangdong Architecture Civil Engineering, 2021, 28(5): 62-64,111. (in Chinese) doi: 10.3969/j.issn.1007-4104.2025.10.033CHEN X C. Analysis of front-braced grouting steel pipe pile in deep foundation excavation engineering[J]. Guangdong Architecture Civil Engineering, 2021, 28（5）: 62-64,111. doi: 10.3969/j.issn.1007-4104.2025.10.033 [17] 陈海涛, 王 伟, 李 伟, 等. 超前注浆端承钢斜撑在基坑工程中的应用[J]. 建筑施工, 2017, 39(9): 1335-1336,1342. (CHEN H T, WANG W, LI W, et al. Application of advanced grouting at end bearing steel inclined strut to foundation pit engineering[J]. Building Construction, 2017, 39(9): 1335-1336,1342. (in Chinese)CHEN H T, WANG W, LI W, et al. Application of advanced grouting at end bearing steel inclined strut to foundation pit engineering[J]. Building Construction, 2017, 39（9）: 1335-1336,1342. (in Chinese) [18] 孙锦剑. 前撑注浆钢管桩在地下两层基坑工程中的应用[J]. 广东土木与建筑, 2024, 31(6): 69-71. (SUN J J. Application of pre-braced grouting steel pipe pile in two-storey underground foundation pit engineering[J]. Guangdong Architecture Civil Engineering, 2024, 31(6): 69-71. (in Chinese) doi: 10.19731/j.gdtmyjz.2024.06.015SUN J J. Application of pre-braced grouting steel pipe pile in two-storey underground foundation pit engineering[J]. Guangdong Architecture Civil Engineering, 2024, 31（6）: 69-71. (in Chinese) doi: 10.19731/j.gdtmyjz.2024.06.015 [19] 戴生良, 张 宁, 黄惟奕, 等. 上海地区不同地质条件自稳式斜撑体系变形特性对比分析[J]. 建筑施工, 2022, 44(10): 2312-2315. (DAI S L, ZHANG N, HUANG W Y, et al. Comparative analysis of deformation characteristics of self-stabilizing inclined strut systems under different geological conditions in Shanghai Area[J]. Building Construction, 2022, 44(10): 2312-2315. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.10.010DAI S L, ZHANG N, HUANG W Y, et al. Comparative analysis of deformation characteristics of self-stabilizing inclined strut systems under different geological conditions in Shanghai Area[J]. Building Construction, 2022, 44（10）: 2312-2315. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.10.010 [20] 王卫东, 王浩然, 徐中华. 上海地区基坑开挖数值分析中土体HS-Small模型参数的研究[J]. 岩土力学, 2013, 34(6): 1766-1774. (WANG W D, WANG H R, XU Z H. Study of parameters of HS-Small model used in numerical analysis of excavations in Shanghai area[J]. Rock and Soil Mechanics, 2013, 34(6): 1766-1774. (in Chinese)WANG W D, WANG H R, XU Z H. Study of parameters of HS-Small model used in numerical analysis of excavations in Shanghai area[J]. Rock and Soil Mechanics, 2013, 34（6）: 1766-1774. (in Chinese) [21] 王卫东, 李 青, 徐中华. 软土地层邻近隧道深基坑变形控制设计分析与实践[J]. 隧道建设(中英文), 2022, 42(2): 163-175. (WANG W D, LI Q, XU Z H. Design and application of deformation control techniques for deep foundation pits adjacent to existing tunnels in soft soil[J]. Tunnel Construction, 2022, 42(2): 163-175. (in Chinese) doi: 10.3973/j.issn.2096-4498.2022.02.001WANG W D, LI Q, XU Z H. Design and application of deformation control techniques for deep foundation pits adjacent to existing tunnels in soft soil[J]. Tunnel Construction, 2022, 42（2）: 163-175. (in Chinese) doi: 10.3973/j.issn.2096-4498.2022.02.001 [22] 宗露丹, 徐中华, 翁其平, 等. 小应变本构模型在超深大基坑分析中的应用[J]. 地下空间与工程学报, 2019, 15(S1): 231-242. (ZONG L D, XU Z H, WENG Q P, et al. Application of small strain constitutive model in the analysis of a ultra large and deep excavation[J]. Chinese Journal of Underground Space and Engineering, 2019, 15(S1): 231-242. (in Chinese) doi: 10.20174/j.juse.2019.s1.035ZONG L D, XU Z H, WENG Q P, et al. Application of small strain constitutive model in the analysis of a ultra large and deep excavation[J]. Chinese Journal of Underground Space and Engineering, 2019, 15（S1）: 231-242. (in Chinese) doi: 10.20174/j.juse.2019.s1.035 [23] 孙海忠, 邓捷程. 基于HS-Small模型软土基坑开挖过程三维数值分析[J]. 建筑施工, 2022, 44(6): 1373-1376. (SUN H Z, DENG J C. 3D numerical analysis of soft soil foundation pit excavation process based on HS-Small model[J]. Building Construction, 2022, 44(6): 1373-1376. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.06.062SUN H Z, DENG J C. 3D numerical analysis of soft soil foundation pit excavation process based on HS-Small model[J]. Building Construction, 2022, 44（6）: 1373-1376. (in Chinese) doi: 10.14144/j.cnki.jzsg.2022.06.062 -
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