Field tests on vertical bearing capacity of pipe piles in cement-improved soil
-
摘要: 依托某水泥土复合管桩工现场载荷试验,分析了竖向荷载作用下水泥土复合管桩轴力、桩侧摩阻力和桩身压缩量沿桩身的分布特征。测试结果表明,竖向荷载下水泥土复合管桩荷载-沉降曲线呈缓变性,桩身轴力沿桩身近似呈线性递减,桩端荷载约占总荷载的15%～20%,水泥土复合管桩桩侧摩阻力承担80%～85%的竖向荷载；水泥土与管桩的界面摩阻力较天然土与管桩界面摩阻力提升6～9倍；水泥土复合管桩桩身压缩量占总沉降量的为20%～30%。研究成果可为水泥土复合管桩竖向承载设计计算提供依据。Abstract: In order to study the load transfer of the pipe piles in cement-improved soil under vertical loads, the axial load tests are conducted to analyze the distribution characteristics of axial force, side friction and compression along the pile body. The results show that the load-settlement curves of the pipe piles in cement-improved soil change slowly and gradually. The axial force of the piles decreases linearly along the pile depth. The vertical loads at the bottom of the piles range from 15% to 20% of the vertical loads, and the side friction of the piles in cement-improved soil bears 80% ~ 85% of the vertical loads. The side friction of the piles in cement-improved soil is 6~9 times that of the piles in natural surrounding soil. The ratio of the pile compression to the total settlement is 20%~30%. The research results may provide technical support for the vertical bearing design practice of the piles in cement-improved soil.
-
Keywords:
- cement-improved pipe pile /
- axial force /
- side friction resistance /
- compression
-
-
![]()
图 7 试桩V-I桩端阻力与位移关系曲线
Figure 7. Relationship curve between end resistance and displacement of pile V-I
表 1 土层物理力学参数
Table 1 Physical and mechanical parameters of soil layer
地层名称 层厚/m 含水率/% 重度/(kN·m-3) 黏聚力/kPa 内摩擦角/(°) 压缩模量/MPa 粉质黏土 2 29.7 19.03 29.6 16.6 5.10 淤泥质粉质黏土 2 37.2 18.28 14.2 10.4 3.72 粉土 7 28.2 18.88 10.9 20.6 8.86 粉质黏土 6 30.2 18.74 29.1 16.9 6.82 淤泥质粉质黏土 25 39.1 17.97 14.0 10.2 3.16 粉质黏土 6 30.6 18.92 33.9 15.9 6.76 粉土 2 25.1 19.57 10.2 21.1 11.05 粉砂 6 — — — — 20 黏土 3 36.4 18.52 31.8 14.3 5.24 
下载: 导出CSV
表 2 各桩型桩侧摩阻力
Table 2 Side frictions of various piles
土层 复合桩/kPa 管桩/kPa 灌注桩/kPa 复合桩/管桩 复合桩/灌注桩 粉质黏土 125 16.00 14.00 7.48 8.55 淤泥质粉质黏土 65 7.00 6.00 8.63 10.08 粉土 120 18.00 16.00 6.20 6.96
下载: 导出CSV
表 3 试桩极限荷载下沉降压缩量
Table 3 Settlement compressions of piles under load of 2200 kN
试桩编号 桩顶荷载/kN 桩顶沉降量/mm 桩身压缩量/mm 桩端沉降/mm 桩身压缩沉降比 V-I 2200 10.23 2.82 7.41 27.57% V-II 2200 12.65 3.02 9.63 23.87% V-III 2200 12.10 3.14 8.96 25.95%
下载: 导出CSV
-
[1] 董平, 陈征宙, 秦然. 混凝土芯水泥土搅拌桩在软土地基中的应用[J]. 岩土工程学报, 2002, 24(2): 204-207. doi: 10.3321/j.issn:1000-4548.2002.02.017 DONG Ping, CHEN Zheng-zhou, QIN Ran. Use of concrete-cored DCM pile in soft ground[J]. Chinese Journal of Geotechnical Engineering, 2002, 24(2): 204-207. (in Chinese) doi: 10.3321/j.issn:1000-4548.2002.02.017
[2] 李俊才, 张永刚, 邓亚光, 等. 管桩水泥土复合桩荷载传递规律研究[J]. 岩石力学与工程学报, 2014, 33(增刊1): 3068-3076. doi: 10.13722/j.cnki.jrme.2014.s1.068 LI Jun-cai, ZHANG Yong-gang, DENG Ya-guang, et al. Load transfer mechanism of composite pile composed of jet-mixing cement and phc pile with core concrete[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(S1): 3068-3076. (in Chinese) doi: 10.13722/j.cnki.jrme.2014.s1.068
[3] 吴迈, 窦远明, 王恩远. 水泥土组合桩荷载传递试验研究[J]. 岩土工程学报, 2004, 26(3): 432-434. doi: 10.3321/j.issn:1000-4548.2004.03.029 WU Mai, DOU Yuan-ming, WANG En-yuan. A study on load transfer mechanism of stiffened DCM pile[J]. Chinese Journal of Geotechnical Engineering, 2004, 26(3): 432-434. (in Chinese) doi: 10.3321/j.issn:1000-4548.2004.03.029
[4] 李立业. 水泥土复合管桩承载特性研究[D]. 南京: 东南大学, 2016. LI Li-ye. Study on the Bearing Capacity of Stiffened DCM Pile[D]. Nanjing: Southeast University, 2016. (in Chinese)
[5] 叶观宝, 蔡永生, 张振. 加芯水泥土桩复合地基桩土应力比计算方法研究[J]. 岩土力学, 2016, 37(3): 672-678. doi: 10.16285/j.rsm.2016.03.008 YE Guan-bao, CAI Yong-sheng, ZHANG Zhen. Research on calculation of pile-soil stress ratio for composite foundation reinforced by stiffened deep mixed piles[J]. Rock and Soil Mechanics, 2016, 37(3): 672-678. (in Chinese) doi: 10.16285/j.rsm.2016.03.008
[6] JAMSAWANG P, BERGADO D T, VOOTTIPRUEX P. Field behaviour of stiffened deep cement mixing piles[J]. Proceedings of the ICE-Ground Improvement, 2010, 164(1): 33-49.
[7] 钱于军, 许智伟, 邓亚光等. 劲性复合管桩的工程应用与试验分析[J]. 岩土工程学报, 2013, 35(增刊2): 998-1001. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2013S2190.htm QIAN Yu-jun, XU Zhi-wei, DENG Ya-guang, et al.Engineering application and test analysis of strength composite piles[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(S2): 998-1001. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2013S2190.htm
[8] VOOTTIPRUEX P, SUKSAWAT T, BERGADO D T, et al. Numerical simulations and parametric study of SDCM and DCM piles under full scale axial and lateral loads[J]. Computers and Geotechnics, 2011, 38(3): 318-329. doi: 10.1016/j.compgeo.2010.11.006
[9] WONGLERT A, JONGPRADIST P. Impact of reinforced core on performance and failure behavior of stiffened deep cement mixing piles[J]. Computers and Geotechnics, 2015, 69: 93-104. doi: 10.1016/j.compgeo.2015.05.003
[10] WANG A H, ZHANG D W, DENG Y G. A simplified approach for axial response of single precast concrete piles in cement-treated soil[J]. International Journal of Civil Engineering, 2018, 16(10): 1491-1501. doi: 10.1007/s40999-018-0341-9
[11] WANG A H, ZHANG D W, DENG Y G.. Lateral response of single piles in cement-improved soil: numerical and theoretical investigation[J]. Computers and Geotechnics, 2018, 102: 164-178. doi: 10.1016/j.compgeo.2018.06.014
[12] 王安辉, 章定文, 谢京臣. 软黏土中劲性复合桩水平承载特性p-y 曲线研究[J]. 岩土工程学报, 2020, 42(2): 381-389. https://www.cnki.com.cn/Article/CJFDTOTAL-XBKJ201129003.htm WANG An-hui, ZHANG Ding-wen, XIE Jing-chen. p-y curves for lateral bearing behavior of strength composite piles in soft clay[J]. Chinese Journal of Geotechnical Engineering, 2020, 42(2): 381-389. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XBKJ201129003.htm
计量
- 文章访问数: 207
- HTML全文浏览量: 25
- PDF下载量: 118
