Visual centrifugal model tests on capacity of anchor piles and displacement field around piles under oblique pull-out loads
-
摘要: 单点系泊系统作为一种新型锚固系统获得越来越多的应用，然而倾斜拉拔荷载下单点系泊锚桩的承载性能及桩周土体变形机理尚不明确。基于人工合成透明土材料搭建了可视化离心模型试验系统，对倾斜拉拔荷载下锚桩的力学响应展开离心模型试验，探讨加载角度对锚桩承载力、失效模式和桩周土位移场的影响规律，并与1g条件下透明土模型试验结果进行定性的对比分析。研究结果表明，开展的基于透明砂土的离心模型试验，可以用于评估现场应力状态下锚桩的承载特性与失效机理、土体内部位移场；桩周土体的位移量沿深度方向差别相对较为明显，锚眼附近的土体位移相对较大；1g条件下土体位移场无法合理反映位移沿桩身方向的变化规律，极限荷载下桩侧土体的变形量小于离心模型试验中的土体变形量。Abstract: The single-point mooring systems have been increasingly used as a new anchorage system. However, the capacity of anchor piles for single-point mooring and the deformation mechanism of soils around the piles under oblique pull-out loads are still unclear. Based on synthetic transparent sand, a visual centrifugal model test system is established to carry out the centrifugal model tests on the mechanical behaviors of the anchor piles under oblique pull-out loads. The effects of loading angle on the pulling resistance, failure mode and soil displacement field are discussed, and the model test results of the transparent sand under 1g condition are also qualitatively compared. The results illustrate that the centrifugal model tests on the transparent sand can be used to evaluate the pulling capacity and failure mechanism of the anchor piles and the internal displacement field of soils under the real stress state. The difference of displacement value of the surrounding soil with depth is obvious, and the relative large soil displacement occurs near the pad eye. The soil displacement field under 1g condition cannot rationally reflect the variation laws of soil displacement along the anchor piles, and the soil deformation value at the pile side under the ultimate resistance is less than that in the centrifugal model tests.
-
-
表 1 熔融石英砂颗粒级配
Table 1 Grain-size distribution of fused quartz
粒径范围/mm 质量百分比/% < 0.5 1.34 0.5~0.6 16.71 0.6~0.85 62.75 0.85~1.0 18.48 > 1.0 0.72 
下载: 导出CSV
表 2 模型试验工况
Table 2 Model test conditions
试验类型 桩径d/mm 长径比L/d 加载角度θ/(°) 50g离心模型
试验8 15 37 45 53 60 75 1g模型试验 12 15 37 45 53 60 75
下载: 导出CSV
-
[1] CARDOSO S P, SABOYA F, TIBANA S, et al. Centrifuge modelling of a combined pile-type anchor subjected to general inclined loading[J]. Marine Structures, 2020, 74: 102815. doi: 10.1016/j.marstruc.2020.102815
[2] HUANG T, O'LOUGHLIN C, GAUDIN C, et al. Drained response of rigid piles in sand under an inclined tensile load[J]. Géotechnique Letters, 2020, 10(1): 30-37. doi: 10.1680/jgele.19.00028
[3] PENG J S, LIU H X, ZHAO Y B, et al. Failure mode and pullout capacity of anchor piles in soils with cohesive and cohesionless properties[J]. Marine Georesources & Geotechnology, 2020, 38(9): 1056-1069.
[4] RAMADAN M I, BUTT S D, POPESCU R. Offshore anchor piles under mooring forces: centrifuge modeling[J]. Canadian Geotechnical Journal, 2013, 50(4): 373-381. doi: 10.1139/cgj-2012-0250
[5] RAMADAN M I, BUTT S D, POPESCU R. Offshore anchor piles under mooring forces: numerical modeling[J]. Canadian Geotechnical Journal, 2013, 50(2): 189-199. doi: 10.1139/cgj-2012-0251
[6] NI Q, HIRD C C, GUYMER I. Physical modelling of pile penetration in clay using transparent soil and particle image velocimetry[J]. Géotechnique, 2010, 60(2): 121-132. doi: 10.1680/geot.8.P.052
[7] QI C G, ISKANDER M, OMIDVAR M. Soil deformations during casing jacking and extraction of expanded-shoe piles, using model tests[J]. Geotechnical and Geological Engineering, 2017, 35(2): 809-826. doi: 10.1007/s10706-016-0145-0
[8] SANG Y, WANG Z T, YU S K, et al. The loading test on the singe pile with pile cap in transparent soil model[J]. Geotechnical Testing Journal, 2019, 42(2): 20170153. doi: 10.1520/GTJ20170153
[9] 周东, 刘汉龙, 仉文岗, 等. 被动桩侧土体位移场的透明土模型试验[J]. 岩土力学, 2019, 40(7): 2686-2694. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201907022.htm ZHOU Dong, LIU Hanlong, ZHANG Wengang, et al. Transparent soil model test on the displacement field of soil around single passive pile[J]. Rock and Soil Mechanics, 2019, 40(7): 2686-2694. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201907022.htm
[10] CAO Z H, LIU H L, KONG G Q, et al. Physical modelling of pipe piles under oblique pullout loads using transparent soil and particle image velocimetry[J]. Journal of Central South University, 2015, 22(11): 4329-4336. doi: 10.1007/s11771-015-2981-0
[11] KONG G Q, CAO Z H, ZHOU H, et al. Analysis of piles under oblique pullout load using transparent-soil models[J]. Geotechnical Testing Journal, 2015, 38(5): 20140109. doi: 10.1520/GTJ20140109
[12] 王永志, 王海, 袁晓铭, 等. 土工离心试验应力相似差异特征与设计准则[J]. 岩土工程学报, 2018, 40(11): 2148-2154. http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract17624.shtml WANG Yongzhi, WANG Hai, YUAN Xiaoming, et al. Difference characteristics of stress similitude for geotechnical centrifuge modelling and design criteria[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(11): 2148-2154. (in Chinese) http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract17624.shtml
[13] SONG Z H, HU Y X, O'LOUGHLIN C, RANDOLPH M F. Loss in anchor embedment during plate anchor keying in clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2009, 135(10): 1475-1485. doi: 10.1061/(ASCE)GT.1943-5606.0000098
[14] ISKANDER M, BATHURST R J, OMIDVAR M. Past, present, and future of transparent soils[J]. Geotechnical Testing Journal, 2015, 38(5): 20150079. doi: 10.1520/GTJ20150079
[15] PINCUS H J, ISKANDER M G, LAI J, et al. Development of a transparent material to model the geotechnical properties of soils[J]. Geotechnical Testing Journal, 1994, 17(4): 425. doi: 10.1520/GTJ10303J
[16] BLACK J A. Centrifuge modelling with transparent soil and laser aided imaging[J]. Geotechnical Testing Journal, 2015, 38(5): 20140231. doi: 10.1520/GTJ20140231
[17] 孔纲强, 刘璐, 刘汉龙, 等. 玻璃砂透明土变形特性三轴试验研究[J]. 岩土工程学报, 2013, 35(6): 1140-1146. http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract15077.shtml KONG Gangqiang, LIU Lu, LIU Hanlong, et al. Triaxial tests on deformation characteristics of transparent glass sand[J]. Chinese Journal of Geotechnical Engineering, 2013, 35(6): 1140-1146. (in Chinese) http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract15077.shtml
[18] GEORGIADIS M, ANAGNOSTOPOULOS C, SAFLEKOU S. Centrifugal testing of laterally loaded piles in sand[J]. Canadian Geotechnical Journal, 1992, 29(2): 208-216. doi: 10.1139/t92-024
[19] DYSON G J, RANDOLPH M F. Monotonic lateral loading of piles in calcareous sand[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2001, 127(4): 346-352. doi: 10.1061/(ASCE)1090-0241(2001)127:4(346)
[20] WANG Z T, XU B, LUAN M T, YANG L Q. An introduction to a new drum centrifuge at DUT[J]. Applied Mechanics and Materials, 2012, 170-173: 3106-3111. doi: 10.4028/www.scientific.net/AMM.170-173.3106
[21] GUO Z, JENG D S, GUO W, et al. Failure mode and capacity of suction caisson under inclined short-term static and one-way cyclic loadings[J]. Marine Georesources & Geotechnology, 2018, 36(1): 52-63.
[22] HAMED M, CANAKCI H, NASR A. Analysis of vertical piles embedded in organic soil under oblique pull-out load[J]. Geotechnical Testing Journal, 2019, 42(5): 20170178. doi: 10.1520/GTJ20170178
[23] ZHAO L, GAUDIN C, O'LOUGHLIN C D, et al. Drained capacity of a suction caisson in sand under inclined loading[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2019, 145(2): 04018107. doi: 10.1061/(ASCE)GT.1943-5606.0001996
[24] API. Recommended Practice 2A-WSD[S]. American Petroleum Institute, 2007.
[25] 徐光明, 章为民. 离心模型中的粒径效应和边界效应研究[J]. 岩土工程学报, 1996, 18(3): 80-86. http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract9029.shtml XU Guangming, ZHANG Weimin. Study on particle size effect and boundary effect in centrifugal model[J]. Chinese Journal of Geotechnical Engineering, 1996, 18(3): 80-86. (in Chinese) http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/abstract/abstract9029.shtml
-
其他相关附件
计量
- 文章访问数: 0
- HTML全文浏览量: 0
- PDF下载量: 0
