Please wait a minute...
Journal of ZheJiang University (Engineering Science)  2022, Vol. 56 Issue (8): 1504-1513    DOI: 10.3785/j.issn.1008-973X.2022.08.004
    
Development of a test apparatus for staged construction of embankment in geotechnical centrifuge model tests
Hong-yang LIU1(),Qiang LUO1,2,*(),Wei-long WANG1,Pin-feng LI1,Hong-fei MA1,Dong-qing ZHANG3
1. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
2. MOE Key Laboratory of High-speed Railway Engineering, Chengdu 610031, China
3. China Railway Eryuan Engineering Group Co. Ltd, Chengdu 610031, China
Download: HTML     PDF(3813KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

A set of programmable staged embankment construction device was developed in order to improve the simulation technology for embankment construction in geotechnical centrifuge modeling. It is functional during centrifuge operation, and consists of a box-like sand container, sand falling push-pull element, a stepper motor controller and a camera system. A combination of stepper motor, planetary gearbox, and ball screw achieves high torque and resolution of dynamic output, so that the sand falling layer, featuring low friction and small deformation, can move back and forth relative to the upper sand container. Then, the high-density zircon sand in the box-like sand container can pass through sand falling holes with different diameters and spacing, which are located on the basal bearing plate. The influence of Coriolis effect on the movement trajectory of the sand particles was significantly reduced by installing segmented deflectors on the edge of sand falling holes. The zircon sands fell along the deflectors to the surface of foundation, and then formed a regular-shaped embankment. The trial experiment showed that the developed apparatus can better simulate the staged construction process of embankment with minimum layer thickness of 20 mm at a centrifugal acceleration of 60g. The relative error of cross section between the simulated embankment and the target embankment was 0.50%~9.50%. This device achieved the similarity between the model embankment and the prototype in terms of geometry, density and strength. The device is characterized by high system reliability, compacted structure and full functionality.



Key wordsgeotechnical centrifuge model test      embankment      simulation of staged construction      sand falling device      Coriolis effect     
Received: 18 August 2021      Published: 30 August 2022
CLC:  TU 43  
Fund:  国家自然科学基金资助项目(51878560);四川省科技计划资助项目 (2021YJ0001)
Corresponding Authors: Qiang LUO     E-mail: 757657495@qq.com;lqrock@swjtu.edu.cn
Cite this article:

Hong-yang LIU,Qiang LUO,Wei-long WANG,Pin-feng LI,Hong-fei MA,Dong-qing ZHANG. Development of a test apparatus for staged construction of embankment in geotechnical centrifuge model tests. Journal of ZheJiang University (Engineering Science), 2022, 56(8): 1504-1513.

URL:

https://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2022.08.004     OR     https://www.zjujournals.com/eng/Y2022/V56/I8/1504


土工离心模型试验中路堤分层填筑装置的研制

为了完善土工离心模型试验中的路堤填筑模拟技术,研制了一套在离心机运转条件下可编程控制的路堤分层填筑装置,其由箱式储砂结构、泄砂推拉机构、步进电机控制系统和摄像系统组成. 采用步进电机-行星减速器-滚珠丝杠的组合方案实现大扭矩、高精度动力输出,使低摩阻、小变形的泄砂层与上部储砂结构前后错动,分隔于储砂结构内的高密度锆砂经承力底板上不等径、不等距泄砂孔定量下泄;通过在泄砂孔边缘加装折线形导流板,显著减弱离心场中Coriolis效应对下泄砂粒运动轨迹的影响,降落至地基面预设区的砂粒分层堆积为形状规整的路堤. 试验表明,研制的填筑装置在60g离心加速度下,能模拟最小分层厚度20 mm的路堤填筑过程,模型横断面与设计面积相对误差为0.50%~9.50%,实现了模型与原型路堤在几何、密度和强度等方面的相似,具有系统可靠、结构紧凑、功能完整等技术特点.


关键词: 土工离心模型试验,  路堤,  分层填筑模拟,  泄砂装置,  Coriolis效应 
Fig.1 Centrifuge (TLJ-2) and model box
Fig.2 Zircon sand for testing
Fig.3 Schematic diagram of box-like sand container
Fig.4 Schematic diagram of sand falling push-pull mechanism
Fig.5 Schematic diagram of slide section design
Fig.6 Free fall trajectory of zircon sand at centrifugal acceleration of 60g
Fig.7 Influence of Coriolis force and design of deflectors
Fig.8 Stepper motor controller
Fig.9 Schematic diagram of camera system
Fig.10 Main structure of staged embankment construction apparatus
Fig.11 Installation of staged embankment construction apparatus
Fig.12 Design parameters of model and sand container
Fig.13 Relationship between height of embankment and time
Fig.14 Embankment model during staged construction
Fig.15 Vertical view of embankment model
[1]   章为民, 徐光明 土石坝填筑过程的离心模拟方法[J]. 水利学报, 1997, (2): 9- 14
ZHANG Wei-min, XU Guang-ming Study on modeling the construction process of embankment damsin centrifugal test[J]. Journal of Hydraulic Engineering, 1997, (2): 9- 14
doi: 10.3321/j.issn:0559-9350.1997.02.002
[2]   巨能攀, 邓天鑫, 李龙起, 等 强震作用下陡倾顺层斜坡倾倒变形机制离心振动台试验[J]. 岩土力学, 2019, 40 (1): 99- 108+117
JU Neng-pan, DENG Tian-xin, LI Long-qi, et al Centrifugal shaking table test on toppling deformation mechanism of steep bedding slope under strong earthquake[J]. Rock and Soil Mechanics, 2019, 40 (1): 99- 108+117
doi: 10.16285/j.rsm.2017.1274
[3]   罗强, 朱江江, 张瑞国, 等 砂土边坡稳定性土工离心模型试验[J]. 岩石力学与工程学报, 2018, 37 (5): 1252- 1259
LUO Qiang, ZHU Jiang-jiang, ZHANG Rui-guo, et al Geotechnical centrifugal model test on sandy soil slope stability[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37 (5): 1252- 1259
doi: 10.13722/j.cnki.jrme.2017.1132
[4]   王海. 土工离心模型试验技术若干关键问题研究[D]. 哈尔滨: 中国地震局工程力学研究所, 2019.
WANG Hai. Research on several crucial problems of geotechnical centrifuge modeling techniques [D]. Harbin: Institute of Engineering Mechanics, China Earthquake Administration, 2019.
[5]   李明, 张嘎, 李焯芬, 等 离心模型试验中边坡开挖设备的研制与应用[J]. 岩土工程学报, 2010, 32 (10): 1638- 1642
LI Ming, ZHANG Ga, LI Chao-fen, et al Development and application of a slope excavation device for centrifugal model tests[J]. Chinese Journal of Geotechnical Engineering, 2010, 32 (10): 1638- 1642
[6]   张敏, 吴宏伟 边坡离心模型试验中的降雨模拟研究[J]. 岩土力学, 2007, 28 (增1): 53- 57
ZHANG Min, WU Hong-wei Rainfall simulation techniques in centrifuge modelling of slopes[J]. Rock and Soil Mechanics, 2007, 28 (增1): 53- 57
doi: 10.16285/j.rsm.2007.s1.084
[7]   何奔, 王欢, 洪义, 等 竖向荷载对黏土地基中单桩水平受荷性能的影响[J]. 浙江大学学报:工学版, 2016, 50 (7): 1221- 1229
HE Ben, WANG Huan, HONG Yi, et al Effect of vertical load on lateral behavior of single pile in clay[J]. Journal of Zhejiang University: Engineering Science, 2016, 50 (7): 1221- 1229
[8]   冯振, 殷跃平 我国土工离心模型试验技术发展综述[J]. 工程地质学报, 2011, 19 (3): 323- 331
FENG Zhen, YIN Yue-pin State of the art review of geotechnical centrifuge modeling test in China[J]. Journal of Engineering Geology, 2011, 19 (3): 323- 331
doi: 10.3969/j.issn.1004-9665.2011.03.005
[9]   BUI PHU DOANH, 罗强, 张良, 等 基于离心模型试验的高强度桩复合地基桩间距效应分析[J]. 铁道学报, 2009, 31 (6): 69- 75
BUI PHU DOANH, LUO Qiang, ZHANG Liang, et al Analysis on pile spacing effect of composite foundation with high strength piles by centrifugal model test[J]. Journal of the China Railway Society, 2009, 31 (6): 69- 75
doi: 10.3969/j.issn.1001-8360.2009.06.012
[10]   朱江江. 基于离心模型试验的高速铁路中低压缩性土地基沉降变形时间效应分析[D]. 成都: 西南交通大学, 2014.
ZHU Jiang-jiang. Deformation timeliness analysis of the middle-lower compressive soil of high-speed railway based on geotechnical centrifuge model tests[D]. Chengdu: Southwest Jiaotong University, 2014.
[11]   刘守华, 蔡正银 土工离心模型填料装置研究[J]. 岩土工程学报, 1996, 18 (3): 74- 79
LIU Shou-hua, CAI Zheng-yin Study of the filling devices in the centrifuge model test[J]. Chinese Journal of Geotechnical Engineering, 1996, 18 (3): 74- 79
doi: 10.3321/j.issn:1000-4548.1996.03.011
[12]   BEASLEY D H, JAMES R G Use of a hopper to simulate embankment construction in a centrifugal model[J]. Géotechnique, 1976, 26 (1): 220- 226
[13]   DAVIES M C R, PARRYR H G Centrifuge modelling of embankments on clay foundations[J]. Soils and Foundations, 1985, 25 (4): 19- 36
doi: 10.3208/sandf1972.25.4_19
[14]   KITAZUME M, MARUYAMA K External stability of group column type deep mixing improved ground under embankment loading[J]. Soils and Foundations, 2006, 46 (3): 323- 340
doi: 10.3208/sandf.46.323
[15]   KITAZUME M, MARUYAMA K Internal stability of group column type deep mixing improved ground under embankment loading[J]. Soils and Foundations, 2007, 47 (3): 437- 455
doi: 10.3208/sandf.47.437
[16]   KITAZUME M, MARUYAMA K. Centrifuge model tests on failure pattern of group column type deep mixing improved ground[C]// Proceedings of the 17th International Offshore and Polar Engineering Conference. Lisbon: [s. n. ], 2007.
[17]   DETERT O, KÖNIG D, SCHANZ T Centrifuge modeling of an adaptive foundation system for embankments on soft soils[J]. Geotechniek, 2012, 16 (4): 46
[18]   BASSETT R H. Centrifugal model tests of embankments on soft alluvial foundations [C]// Proceedings of the 8th International Conference Soil Mechanics and Foundation Engineering. Moscow: [s. n. ], 1973.
[19]   吴宏伟, 洪义. 用于土工离心机中模拟高速公路建造的装置及方法: CN104501771 B [P]. 2017-04-26.
[20]   NG C W W, VAN LAAK P A, TANG W H, et al The Hong Kong geotechnical centrifuge and its unique capabilities[J]. Sino-Geotechnics, 2001, 83: 5- 12
[21]   SCHOFIELD A N Cambridge geotechnical centrifuge operations[J]. Géotechnique, 1980, 30 (3): 227- 268
[22]   肖国先. 料仓内散体流动的数值模拟研究[D]. 南京: 南京工业大学, 2004.
XIAO Guo-xian. Numerical simulation study upon granular materials flow in silos[D]. Nanjing: Nanjing University of Technology, 2004.
[1] Zheng-shu ZHAN,Yu ZHAO,Teng LIANG,Zhun LIU,Wei WANG. Discrete element simulation of granular chute flows within centrifugal field[J]. Journal of ZheJiang University (Engineering Science), 2022, 56(6): 1232-1240.
[2] Meng-fan LIU,Gang-feng WU,Ke-feng ZHANG,Ping DONG. 2D non-cohesive earthen embankment breach model based on linear erosion formula[J]. Journal of ZheJiang University (Engineering Science), 2022, 56(3): 569-578.
[3] Wu-ming LENG,Qi-shu ZHANG,Fang XU,Hui-kang LENG,Ru-song NIE,Xiu-hang YANG. Additional confining pressure field and enhancement effect of prestressed embankment[J]. Journal of ZheJiang University (Engineering Science), 2020, 54(5): 858-869.
[4] ZHUANG Yan, CHENG Xin-ting, XIAO Heng-lin, LIU Huan-zi, ZHOU Bei-he, LI Jia-jun. Working performance of reinforced cushion in piled embankment[J]. Journal of ZheJiang University (Engineering Science), 2018, 52(12): 2279-2284.
[5] ZHANG Jun feng, DAI Xiao song, ZOU Wei lie, XU Shun ping, LI Zi you. Experiments on pavement performance of solidified sediment modified with cement[J]. Journal of ZheJiang University (Engineering Science), 2015, 49(11): 2165-2171.
[6] WANG Ya-jun, ZHANG Wo-hua. Comprehensive sensitivity on fuzzy-stochastic damage field of
embankment structure
[J]. Journal of ZheJiang University (Engineering Science), 2011, 45(9): 1672-1679.
[7] HU Ya-yuan. Settlement of soft ground induced by cycle load considering
secondary settlement
[J]. Journal of ZheJiang University (Engineering Science), 2011, 45(1): 106-111.
[8] ZHANG Kun, LI Dong-Qiang, LI Jian-Yu, TONG Gang-Jiang. Cooling effect of ventilated experimental embankment of
Qinghai-Tibet high-grade road
[J]. Journal of ZheJiang University (Engineering Science), 2010, 44(10): 1845-1850.
[9] ZHANG Jun, ZHENG Dun-Jie, MA Jiang. Calculation for pile efficacy of geosynthetic-reinforced and
pilesupported embankment
[J]. Journal of ZheJiang University (Engineering Science), 2010, 44(10): 1950-1954.