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Study of bearing characteristics of combined suction caisson foundation
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摘要: 基于吸力式沉箱基础应用于桥梁工程的背景, 考虑不同数量的沉箱组合和沉箱间距, 通过数值模拟的方法研究了吸力式沉箱组合基础的承载特性, 重点分析了组合基础与单个基础承载性状的差异, 以及连接各沉箱的顶板对基础承载力的贡献。计算结果表明, 沉箱组合基础与单个沉箱基础的荷载-位移曲线类型都相同; 受类似于“群桩”效应的影响, 竖向荷载作用下组合基础中的沉箱承载力不能完全发挥, 但由于沉箱之间的连接顶板可以提供阻力, 所以当沉箱间距较大时组合基础的承载力会大于相应数量单个基础的承载力之和, 且随着沉箱间距的增大而增大; 对于水平荷载作用下的吸力式沉箱组合基础, 其承载力大于相应数量单个基础的承载力之和, 连接顶板底部与土体之间的摩擦和挤压对于组合基础承载力的提高可以忽略不计。Abstract: Based on the application background of the suction caisson foundation in bridge engineering, a numerical simulation method is used to investigate the bearing performance of the combined suction caisson foundation, and the number and spacings of caissons are considered. The effort is focused on the difference of bearing performance between the combined foundation and the single foundation, and on the contributions of connecting roofs to the bearing capacity of foundation. The analysis results show that the load-displacement curves of the combined caisson foundation are the same as those of the single caisson foundation. Similar to the pile group effect, the vertical bearing capacity of the caisson cannot be fully utilized in the combined foundation. Due to the contribution of the connecting roof between caissons, the vertical bearing capacity of the combined foundation will be greater than the sum of the corresponding numbers of the single suction foundation under a large caisson spacing, and it increases with the increasing caisson spacing. The lateral bearing capacity of the combined foundation is greater than the sum of the corresponding numbers of single suction foundation, and the contribution of connection roof can be neglected.
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图 2 吸力式沉箱组合基础水平受荷方向
Figure 2. Lateral loading direction of combined suction caisson foundation
图 3 单吸力式沉箱基础的竖向荷载-位移曲线
Figure 3. Vertical load-displacement curves of single suction caisson foundation
图 4 单吸力式沉箱基础的水平荷载-位移曲线
Figure 4. Lateral load-displacement curves of single suction caisson foundation
图 5 不同间距下沉箱组合基础竖向荷载
Figure 5. Vertical load-displacement curves of combined caissons foundation under different spacings
图 6 不同间距下沉箱组合基础竖向荷载-位移曲线
Figure 6. Lateral load-displacement curves of combined caissons foundation under different spacings
图 7 有无接触条件下沉箱组合基础竖向荷载-位移曲线
Figure 7. Vertical load-displacement curves of combined caissons foundation with or without connection roof
图 8 有无接触条件下沉箱组合基础水平荷载-位移曲线
Figure 8. Lateral load-displacement curves of combined caissons foundation with or without connection roof
表 1 计算工况
Table 1. Test programs
工况 沉箱数量 直径/m 长径比 间距/m 壁厚/m 1 1 4，8 0.5，1.0，2.0 / 0.2 2 2 4 1.0 8，10，12 0.2 3 3 4 1.0 8，10，12 0.2 4 4 4 1.0 8，10，12 0.2 
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表 2 单吸力式沉箱基础竖向极限承载力
Table 2. The vertical ultimate bearing capacity of single suction caisson foundations
kN 直径/m 长径比 0.5 1.0 2.0 4 4 600 5 200 6 300 8 16 600 20 900 27 000
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表 3 单吸力式沉箱基础水平极限承载力
Table 3. Lateral ultimate bearing capacity of single suction caisson foundation
kN 直径/m 长径比 0.5 1.0 2.0 4 2 300 2 550 3 750 8 7 800 8 500 16 000
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表 4 吸力式组合基础竖向极限承载力
Table 4. Vertical ultimate bearing capacity of combined suction caisson foundation
沉箱数量 间距/m 承载力/(103 kN) 2 8 9.5 (0.91) 2 10 11.5(1.11) 2 12 15.0(1.44) 3 8 13.5(0.87) 3 10 16.5(1.06) 3 12 21.0(1.35) 4 8 16.5(0.79) 4 10 25.0(1.20) 4 12 36.0(1.73) 注：()中数值为该承载力与相应数量单沉箱基础承载力之和之比。
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表 5 吸力式组合基础水平极限承载力
Table 5. Lateral ultimate bearing capacity of combined suction caisson foundations
沉箱数量 间距/m 承载力/(103 kN) 2 8 7.0(1.37) 2 10 7.1(1.39) 2 12 7.9(1.55) 3 8 9.5(1.24) 3 10 12.0(1.57) 3 12 13.0(1.70) 4 8 14.0(1.37) 4 10 15.5(1.52) 4 12 17.5(1.72) 注：()中数值为该承载力与相应数量单沉箱基础承载力之和之比。
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表 6 顶板有无接触条件下组合基础的竖向极限承载力
Table 6. Vertical ultimate bearing capacity of combined suction caisson foundation with or without connection roof
沉箱数量 2 3 4 顶板有无接触 有 无 有 无 有 无 承载力/kN 11 500 8 800 16 500 11 000 25 000 12 500
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[1] 张永涛, 杨炎华, 黎冰, 等.桥梁吸力式沉箱基础承载特性试验研究[J].岩土工程学报, 2015, 37(1): 177-182. http://www.cqvip.com/QK/95758X/201501/1005691277.html ZHANG Yongtao, YANG Yanhua, LI Bing, et al. Model tests on bearing performance of suction caisson foundation for bridges[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(1): 177-182. (in Chinese) http://www.cqvip.com/QK/95758X/201501/1005691277.html [2] RAO S N, LATHA K H, PALLAVI B, et al. Studies on pullout capacity of anchors in marine clays for mooring systems[J]. Applied Ocean Research, 2006, 28(2): 103-111. doi: 10.1016/j.apor.2006.08.001 [3] GAO Yufeng, QIU Yue, LI Bing, et al. Experimental studies on the anti-uplift behavior of the suction caissons in sand[J]. Applied Ocean Research, 2013, 43: 37-45. doi: 10.1016/j.apor.2013.08.001 [4] BANG S, JONES K D, KIM K O, et al. Inclined loading capacity of suction piles in sand[J]. Ocean Engineering, 2011, 38(7): 915-924. doi: 10.1016/j.oceaneng.2010.10.019 [5] JONESA K D, BANG S, CHO Y. Pullout capacity of embedded suction anchors in sand[J]. Ocean Engineering, 2007, 34(16): 2107-2114. doi: 10.1016/j.oceaneng.2007.05.007 [6] KUMAR N D, RAO S N. Earth pressures on caissons in marine clay under lateral loads—a laboratory study[J]. Applied Ocean Research, 2010, 32(1): 58-70. doi: 10.1016/j.apor.2010.04.003 [7] 黎冰, 郑翔, 高玉峰, 等.砂土中吸力式沉箱基础抗拔承载特性试验研究[J].岩土工程学报, 2013, 35(5): 902-907. LI Bing, ZHENG Xiang, GAO Yufeng, et al. Model tests on pull-out capacity of suction caisson foundation in sand[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(5): 902-907. (in Chinese) [8] 金书成, 仇正中, 张永涛, 等.桥梁吸力式沉箱组合基础静载试验研究[J].桥梁建设, 2015, 45(1): 62-67. http://www.cnki.com.cn/Article/CJFDTotal-QLJS201501011.htm JIN Shucheng, QIU Zhenzhong, ZHANG Yongtao, et al. Static load test study of suction caisson combined foundation for bridge[J]. Bridge Construction, 2015, 45(1): 62-67. (in Chinese) http://www.cnki.com.cn/Article/CJFDTotal-QLJS201501011.htm [9] ZHU B, KONG D Q, CHEN R P, et al. Installation and lateral loading tests of suction caissons in silt[J]. Canadian Geotechnical Journal, 2011, 48(7): 1070-1084. doi: 10.1139/t11-021 [10] 朱斌, 应盼盼, 郭俊科, 等.海上风电机组吸力式桶形基础承载力分析与设计[J].岩土工程学报, 2013, 35(增刊1): 443-450. http://d.old.wanfangdata.com.cn/Conference/8127344 ZHU Bin, YING Panpan, GUO Junke, et al. Analysis and design of bearing capacity of suction caisson foundations of offshore wind turbines[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(Suppl1): 443-450. (in Chinese) http://d.old.wanfangdata.com.cn/Conference/8127344 [11] 李大勇, 冯凌云, 张宇坤, 等.饱和细砂中进行裙式吸力式基础水平单调加载模型试验——承载力及变形分析[J].岩土工程学报, 2013, 35(11): 2030-2037. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=ytgc201311012&dbname=CJFD&dbcode=CJFQ LI Dayong, FENG Lingyun, ZHANG Yukun, et al. Model tests of skirted suction caissons in saturated fine sand under horizontal monotonic loading: lateral bearing capacity and deformations[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(11): 2030-2037. (in Chinese) http://kns.cnki.net/KCMS/detail/detail.aspx?filename=ytgc201311012&dbname=CJFD&dbcode=CJFQ [12] BYRNE B W, HOULSBY G T. Foundations for offshore wind turbines[J]. The Philosophical Transactions of the Royal Society, 2003, 361(1813): 2909-2930. doi: 10.1098/rsta.2003.1286 [13] BYRNE B W, HOULSBY G T. Experimental investigations of the response of suction caissons to transient vertical loading[J]. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 2002, 128(11): 926-939. doi: 10.1061/(ASCE)1090-0241(2002)128:11(926) [14] HOULSBY G T, KELLY R B, HUXTABLE J, et al. Field trials of suction caissons in clay for offshore wind turbine foundations[J]. Géotechnique, 2005, 55(4): 287-296. doi: 10.1680/geot.2005.55.4.287 [15] HOULSBY G T, KELLY R B, HUXTABLE J, et al. Field trials of suction caissons in sand for offshore wind turbine foundations[J]. Géotechnique, 2006, 56(1): 3-10. doi: 10.1680/geot.2006.56.1.3 -
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