超大型深水沉井下沉及渗流的离心模型试验研究

蒋炳楠; 马建林; 王蒙婷; 李蜀南; 周和祥

doi:10.11779/CJGE202012016

超大型深水沉井下沉及渗流的离心模型试验研究 English Version

西南交通大学土木工程学院,四川　成都　610031

基金项目:

中国铁路总公司科技研究开发计划项目 2013G001-A-2

国家重点研发计划专项课题 2016YFC0802203

详细信息

作者简介:
蒋炳楠(1992—),男,博士研究生,主要从事深基础方面的理论及应用研究工作。E-mail：1183122662@qq.com

通讯作者:
马建林, E-mail：majianlin01@126.com

中图分类号: TU753.64
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- 文章访问数: 220
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出版历程
- 收稿日期: 2019-09-22
- 网络出版日期: 2022-12-05
- 刊出日期: 2020-11-30

Centrifugal model tests on sinking and seepage of a large deep-water open caisson

School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China

摘要

摘要: 以世界最大深水沉井基础为原型,通过离心机再现原型应力场,模拟沉井在埋深超过30 m后的下沉过程和吸泥引起的渗流场,结合原型沉井实测数据对比分析沉井下沉期间的受力,发现超大型深水沉井侧压力分布主要特点为在台阶处较小,刃脚附近存在应力松弛,台阶上下区段均存在应力集中且台阶以下更明显。沉井下沉时侧阻大于接高时,并根据侧压力分布特性给出了沉井竖直状态下侧阻的计算方法。结合渗流数据,分析得出吸泥会使侧壁下部土体变得松散,侧压力大幅减小并与渗透力负相关。当沉井受力平衡时,渗流作用对侧阻平均值的变化影响较小,但对侧阻的分布形式影响较大,并可能打破沉井的受力平衡状态引起翻砂突沉。沉井下沉时对侧壁土体的挤压会引起部分土体应力集中和超静孔压的上升；下沉结束后,部分超静孔压沿排水路径迅速消散,侧壁土体整体上发生竖向固结,由下沉引起的部分挤土应力集中会缓慢消散。
- 沉井 /
- 离心机试验 /
- 渗流 /
- 侧压力
Abstract: Based on a largest deep-water open caisson, the centrifuge model tests simulate the seepage field caused by mud suction during sinking when the caisson is buried more than 35 m deep. By comparing and analyzing the forces with the measured data from the prototype caisson, the main characteristics are as follows: the distribution of the lateral pressure is small at the step, the stress relaxes near the blade foot, and it concentrates in the upper and lower sections of the step, while it is more obvious below the step. When the lateral resistance during sinking is greater than the heightening, according to the distribution characteristics of lateral pressure, the method for calculating the side resistance in the vertical state of the caisson is given. The analysis also shows that the seepage effect caused by the mud suction will make the soil at the lower section of side wall become loose, and the lateral pressure is greatly reduced and negatively correlated with the seepage force. And may break the stress balance of the caisson and cause gushing sand and sudden sinking. When sinking, the extrusion of side wall will cause stress concentration and the increase of the excess pore water pressure. After sinking, the excess pore water pressure will dissipate rapidly along the drainage path, and vertical consolidation of soil on the sidewall occurs, and part of the stress concentration of soil caused by subsidence will slowly dissipate.
- open caisson /
- centrifugal model test /
- seepage /
- lateral pressure

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图 1 沉井模型示意图

Figure 1. Schematic diagram of open caisson model

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图 2 试验模型制备

Figure 2. Test soil in model box

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图 3 渗流系统

Figure 3. Seepage system

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图 4 试验照片

Figure 4. Photo of test site

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图 5 各测点有效应力随时间变化

Figure 5. Variation of effective stress at measuring points with time

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图 6 模型试验静置状态与静土压力理论值对比

Figure 6. Difference of lateral pressure between resting state of model tests and theory of static earth pressure

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图 7 渗流对侧压力的影响

Figure 7. Influences of seepage on lateral pressure

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图 8 渗透力引起的翻砂示意图

Figure 8. Schematic diagram of gushing sand and sudden sinking caused by seepage force

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图 9 沉井下沉不同状态侧压力对比

Figure 9. Comparison of different states of open caisson

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图 10 现场试验与模型试验下沉期间侧压力对比

Figure 10. Comparison of prototype and model tests on lateral pressure during sinking

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图 11 侧压力计算模型

Figure 11. Model for lateral pressure

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图 12 不同计算方法比较（埋深39 m和埋深45 m）

Figure 12. Comparison of different methods (buried depths of 39 and 45 m)

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图 13 应力恢复程度随时间变化

Figure 13. Dissipation of stress concentration over time

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图 14 下沉前后孔压变化

Figure 14. Variation of pore water pressure before and after sinking

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图 15 超孔隙水压力和应力集中的消散模型

Figure 15. Model for dissipation of excess pore pressure and stress concentration

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图 16 原型沉井接高期间应力消散

Figure 16. Stress dissipation of prototype caisson during heightening

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表 1 离心模型与原型的相似关系

Table 1 Similarity relation between centrifugal model and prototype

物理量	相似比	物理量	相似比
长度	1∶n	弹性模量	1∶1
密度	1∶1	黏聚力	1∶1
应力	1∶1	内摩擦角	1∶1
应变	1∶1	抗剪强度	1∶1
位移	1∶n	时间	1∶n²

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表 2 土体基本参数

Table 2 Basic parameters of soil

土样类别	土颗粒相对密度	内摩擦角/(°)	黏聚力/kPa	孔隙比	饱和重度/(kN·m^-3)	渗透系数/10^-4	与井壁摩擦系数
粉砂	2.704	36.2	0	0.731	19.84	6.8	0.472

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表 3 原型沉井土层地勘参数表

Table 3 Geophysical parameters of soil of prototype caisson

土层编号	土层类别	内摩擦角ϕ/(°)	孔隙比	侧摩阻力标准值/kPa	层底标高/m
1	细砂	42.1	0.65	15	-34.3
2	粉砂	36.4	0.79	15	-48.8
3	粉砂	36.4	0.73	18	-65.0
4	细砂	37.1	0.69	18	-70.1
5	中砂	36.6	0.49	22	-74.5
6	粗砂	40.8	0.50	22	-81.1
7	细砂	41.0	0.59	20	-93.9
8	粗砂	39.3	0.64	25	-102.3
9	细砂	36.6	0.61	22	-114.0

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参考文献(29)

[1]	NONVEILLER E. Open caissons for deep foundations[J]. Journal of the Geotechnical and Geoenvironmental Engineering, ASCE, 1987, 113(5): 424-439. doi: 10.1061/(ASCE)0733-9410(1987)113:5(424)
[2]	TANIMOTO K, TAKAHASHI S. Design and construction of caisson breakwaters: the Japanese experience[J]. Coastal Engineering, 1994, 22(1/2): 57-77.
[3]	胡中波. 深大沉井基底土层承载特性研究[D]. 成都: 西南交通大学, 2016. HU Zhong-bo. Bearing Characteristics Research of the Soil Below Large-Sized Caisson[D]. Chengdu: Southwest Jiaotong University, 2016. (in Chinese)
[4]	张凤祥. 沉井沉箱设计、施工及实例[M]. 北京: 中国建筑工业出版社, 2010. ZHANG Feng-xiang. Design, Construction and Examples of Caissons and Open Caissons[M]. Beijing: China Architecture and Building Press, 2010. (in Chinese)
[5]	LUKE A M, RAUCH A F, OLSON R E, et al. Components of suction caisson capacity measured in axial pullout tests[J]. Ocean Engineering, 2005, 32(7): 878-891. doi: 10.1016/j.oceaneng.2004.10.007
[6]	SAMUI P, DAS S, KIM D. Uplift capacity of suction caisson in clay using multivariate adaptive regression spline[J]. Ocean Engineering, 2011, 38(17): 2123-2127.
[7]	LIAN J, CHEN F, WANG H. Laboratory tests on soil-skirt interaction and penetration resistance of suction caissons during installation in sand[J]. Ocean Engineering, 2014, 84(3): 1-13.
[8]	YEA G G, KIM T H. Vertical cutting edge forces measured during the sinking of pneumatic caisson[J]. Marine Georesources & Geotechnology, 2012, 30(2): 103-121.
[9]	CHIOU J S, KO Y Y, HSU S Y, et al. Testing and analysis of a laterally loaded bridge caisson foundation in gravel[J]. Soils & Foundations, 2012, 52(3): 562-573.
[10]	GEROLYMOS N, GAZETAS G. Development of winkler model for static and dynamic response of caisson foundations with soil and interface nonlinearities[J]. Soil Dynamics & Earthquake Engineering, 2006, 26(5): 363-376.
[11]	ZHONG R, HUANG M S. Winkler model for dynamic response of composite caisson-piles foundations: seismic response[J]. Soil Dynamics and Earthquake Engineering, 2013, 55(13): 182-194.
[12]	ZAFEIRAKOS A, GEROLYMOS N, DROSOS V. Incremental dynamic analysis of caisson-pier interaction[J]. Soil Dynamics & Earthquake Engineering, 2013, 48(5): 71-88.
[13]	铁路桥涵地基和基础设计规范：TB 10093—2017[S]. 2017. Code for Design on Subsoil and Foundation of Railway Bridge and Culvert: TB 10093—2017[S]. 2017. (in Chinese)
[14]	建筑地基基础设计规范：GB 50007—2011[S]. 2012. Code for Design of Building Foundation: GB 50007—2011[S]. 2012. (in Chinese)
[15]	给水排水工程钢筋混凝土沉井结构设计规程：CECS 137: 2015[S]. 2015. Specification for Structural Design of Reinforced Concrete Sinking Well of Water Supply and Sewage Engineering: CECS 137: 2015[S]. 2015. (in Chinese)
[16]	陈晓平, 茜平一, 张志勇. 沉井基础下沉阻力分布特征研究[J]. 岩土工程学报, 2005, 27(2): 148-152. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200502003.htm CHEN Xiao-ping, QIAN Ping-yi, ZHANG Zhi-yong. Study on penetration resistance distribution characteristic of sunk shaft foundation[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(2): 148-152. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200502003.htm
[17]	穆保岗, 朱建民, 牛亚洲. 南京长江四桥北锚碇沉井监控方案及成果分析[J]. 岩土工程学报, 2011, 33(2): 269-274. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201102019.htm MU Bao-gang, ZHU Jian-min, NIU Ya-zhou. Monitoring and analysis of north anchorage caisson of Fourth Nanjing Yangtze River Bridge[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(2): 269-274. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201102019.htm
[18]	朱建民, 龚维明, 穆保岗, 等. 南京长江四桥北锚碇沉井下沉安全监控研究[J]. 建筑结构学报, 2010, 31(8): 112-117. https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201008017.htm ZHU Jian-min, GONG Wei-ming, MU Bao-gang, et al. Sinking safety monitoring research on north anchorage caisson of the Forth Nanjing Yangtze River Bridge[J]. Journal of Building Structures, 2010, 31(8): 112-117. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JZJB201008017.htm
[19]	蒋炳楠, 马建林, 褚晶磊, 等. 水中超深大沉井施工期间侧压力现场监测研究[J]. 岩土力学, 2019, 40(4): 1551-1560. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201904038.htm JIANG Bing-nan, MA Jian-lin, CHU Jing-lei, et al. On-site monitoring of lateral pressure of ultra-deep large and subaqueous open caisson during construction[J]. Rock and Soil Mechanics, 2019, 40(4): 1551-1560. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201904038.htm
[20]	王建, 刘杨, 张煜. 沉井侧壁摩阻力室内试验研究[J]. 岩土力学, 2013, 34(3): 659-666. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201303008.htm WANG Jian, LIU Yang, ZHANG Yu. Model test on sidewall friction of open caisson[J]. Rock and Soil Mechanics, 2013, 34(3): 659-666. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201303008.htm
[21]	李伟雄. 基于被动土压力的沉井结构分析[J]. 岩土工程学报, 2005, 27(11): 1341-1345. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200511022.htm LI Wei-xiong. Analysis of Structure of passive earth pressure on open caisson[J]. Chinese Jounal of Geotechnical Engineering, 2005, 27(11): 1341-1345. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC200511022.htm
[22]	周和祥, 马建林, 张凯, 等. 沉井下沉阻力离心模型试验研究[J]. 岩土力学, 2019, 40(10): 3969-3976. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201910032.htm ZHOU He-xiang, MA Jian-lin, ZHANG Kai, et al. Study on sinking resistance of large and deep caisson based on centrifugal model test[J]. Rock and Soil Mechanics, 2019, 40(10): 3969-3976. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201910032.htm
[23]	周和祥, 马建林, 张凯, 等. 沉井侧壁摩阻力分布特性试验研究[J]. 桥梁建设, 2018, 48(5): 27-32. https://www.cnki.com.cn/Article/CJFDTOTAL-QLJS201805006.htm ZHOU He-xiang, MA Jian-lin, ZHANG Kai, et al. Experimental study on the distribution characteristics of friction resistance on sidewall of the caisson[J]. Bridge Construction, 2018, 48(5): 27-32. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-QLJS201805006.htm
[24]	褚晶磊, 马建林, 蒋炳楠, 等. 水中沉井下沉期侧壁摩阻力分布试验研究[J]. 岩土工程学报, 2019, 41(4): 707-716. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201904018.htm CHU Jing-lei, MA Jian-lin, JIANG Bing-nan, et al. Experimental study on side friction distribution of caissons during sinking in water[J]. Chinese Journal of Geotechnical Engineering, 2019, 41(4): 707-716. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201904018.htm
[25]	蒋炳楠, 马建林, 李孟豪, 等. 水中沉井下沉期间刃脚空间受力试验研究[J]. 岩土力学, 2019, 40(5): 1693-1703. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201905009.htm JIANG Bing-nan, MA Jian-lin, LI Meng-hao, et al. Experiments on spatial stress of foot blade during caisson sinking in water[J]. Rock and Soil Mechanics, 2019, 40(5): 1693-1703. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX201905009.htm
[26]	蒋炳楠. 沪通大桥超深大沉井下沉阻力及突沉现场监测研究[D]. 成都: 西南交通大学, 2016. JIANG Bing-nan. Resistance and Suddenly Sinking Monitor Research of Deep and Large Open Caisson of Hutong Bridge[D]. Chengdu: Southwest Jiaotong University, 2016. (in Chinese)
[27]	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. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC603.011.htm XU Guang-ming, ZHANG Wei-min. Study on particle size effect and boundary effect in centrifugal model[J]. Chinese Journal of Geotechnical Engineering, 1996, 18(3): 80-86. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC603.011.htm
[28]	交通部第一公路总公司. 公路施工手册：桥涵[M]. 北京: 人民交通出版社, 2000. First Highway Corporation of the Ministry of Communications. Highway Construction Manual: Bridge and Culvert[M]. Beijing: China Communications Press, 2000. (in Chinese)
[29]	太沙基. 理论土力学[M]. 徐志英,译.北京: 地质出版社, 1960.