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| Research and application of a new excavation method in centrifuge model tests on foundation pit engineering |
| LI Lianxiang1，2，FU Qinghong1，2，ZHANG Yonglei1，2，LU Fenting1，2 |
(1. Foundation Pit and Deep Foundation Engineering Research Center，Shandong University，Jinan，Shandong 250061，China；
2. School of Civil Engineering，Shandong University，Jinan，Shandong 250061，China) |
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Abstract Three common excavation methods in centrifuge model tests were reviewed，including the excavation at 1 g，the drainage of appropriate liquid to simulate excavation and the excavation in-flight using a micro robot. A new excavation device was designed and developed on the basis of the understanding of the excavation processes. It was confirmed to be feasible in a centrifuge model test on foundation pit engineering in sand ground. Compared with the traditional methods，this method can be used to realize the excavation in-flight，to simulate more correctly the lateral earth pressure，and to simplify the excavation process. In the test，the multiple types of sensors were arranged to form a three-dimensional measurement. The test results were compared with the numerical simulations. It was found that the test results were always smaller than those from simulations. The surface settlement profile caused by excavations was a spandrel type. The position of the maximum induced bending moment of the retaining wall moved down along with excavations，but the moving rate decreased gradually. The upper excavation had little impact on the deep earth pressure. Similarly，the changes of the shallow earth pressure were not obvious when the lower soil was excavated.
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| [1] 中华人民共和国行业标准编写组. JGJ 120—2012建筑基坑支护技术规程[S]. 北京：中国建筑工业出版社，2012.(The Professional Standards Compilation Group of People?s Republic of China. JGJ 120—2012 Technical specification for retaining and protection of building foundation excavations[S]. Beijing：China Architecture and Building Press，2012.(in Chinese))
[2] LYNDON A，SCHOFIELD A N. Centrifuge model test of short term failure in London clay[J]. Geotechnique，1970，20(4)：440–442.
[3] 刘金元. 软土基坑的离心模型试验研究[博士学位论文][D].上海：同济大学，1999.(LIU Jinyuan. Centrifugal model test in soft soil foundation pit[Ph. D. Thesis][D]. Shanghai：Tongji University，1999. (in Chinese))
[4] 马险峰，张海华，朱卫杰，等. 软土地区超深基坑变形特性离心模型试验研究[J]. 岩土工程学报，2009，31(9)：1 371–1 377.(MA Xianfeng，ZHANG Haihua，ZHU Weijie，et al. Centrifuge model tests on deformation of ultra-deep foundation pits in soft ground[J]. Chinese Journal of Geotechnical Engineering，2009，31(9)：1 371–1 377.(in Chinese))
[5] 丁春林，孟晓红. 承压水基坑离心模型试验与现场实测分析[J]. 同济大学学报：自然科学版，2008，36(1)：22–26.(DING Chunlin，MENG Xiaohong. Centrifuge model test and field measurement analysis for foundation pit with confined water[J]. Journal of Tongji University：Natural Science，2008，36(1)：22–26.(in Chinese))
[6] 孙玉永，周顺华. 基于离心模型试验的基坑突涌模式及机制研究[J]. 岩石力学与工程学报，2012，29(12)：2 551–2 557.(SUN Yuyong，ZHOU Shunhua. Mode and mechanism of bursting foundation pit based on centrifugal model test[J]. Chinese Journal of Rock Mechanics and Engineering，2012，29(12)：2 551–2 557.(in Chinese))
[7] 梁发云，褚 峰，宋 著，等. 紧邻地铁枢纽深基坑变形特性离心模型试验研究[J]. 岩土力学，2012，33(3)：657–664.(LIANG Fayun，CHU Feng，SONG Zhu，et al. Centrifugal model test research on deformation behaviors of deep foundation pit adjacent to metro stations[J]. Rock and Soil Mechanics，2012，33(3)：657–664.(in Chinese))
[8] RICHARDS D J，POWRIE W. Centrifuge model tests on doubly propped embedded retaining walls in overconsolidated kaolin clay[J]. Géotechnique，1998，48(6)：833–846.
[9] ONG D E L，LEUNG C F，CHOW Y K. Pile behavior due to excavation-induced soil movement in clay. I：stable wall[J]. Journal of and Geoenvironmental Geotechnical Engineering，2006，132(1)：36–44.
[10] LEUNG C F，ONG D E L，CHOW Y K. Pile behavior due to excavation-induced soil movement in clay. II：collapsed wall[J]. Journal of Geotechnical and Geoenvironmental Engineering，2006，132(1)：45–53.
[11] POWRIE W，KANTARTZI C. Ground response during diaphragm wall installation in clay：centrifuge model tests[J]. Geotechnique，1996，46(4)：725–739.
[12] BOLTON M D，POWRIE W. The collapse of diaphragm walls retaining clay[J]. Geotechnique，1987，37(3)：335–353.
[13] 冉光斌，宁张伟，洪建忠，等. 具有多道支撑的深基坑开挖离心模拟试验方法[J]. 地下空间与工程学报，2010，6(6)：1 142–1 145. (RAN Guangbin，NING Zhangwei，HONG Jianzhong，et al. Centrifuge model test method of deep foundation pit excavation with multi-layer props[J]. Chinese Journal of Underground Space and Engineering，2010，6(6)：1 142–1 145.(in Chinese))
[14] 魏少伟. 基坑开挖对坑底已建隧道影响的数值与离心试验研究[博士学位论文][D]. 天津：天津大学，2010.(WEI Shaowei. Centrifuge and Numerical studies of the influence of basement excavation on the underlying tunnel[Ph. D. Thesis][D]. Tianjin：Tianjin University，2010.(in Chinese))
[15] KIMUA T，TAKEMURE J，HIROOKA A，et al. Excavation in soft clay using an in-flight excavator[C]// Proceedings of the International Conference on Geotechnical Centrifuge Modelling. Rotterdam：[s.n.]，1994：649–654.
[16] GAUDIN C，GARNIER J，GAUDICHEAU P，et al. Use of a robot in-flight excavation in front of an embedded wall[C]// Newfoundland：International Conference on Physical Modelling in Geotechnics. [S.l.]：[s. n.]，2002：77–88. |
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2016, Vol. 35 
