›› 2018, Vol. 39 ›› Issue (1): 139-150.doi: 10.16285/j.rsm.2016.0231

• 基础理论与实验研究 • 上一篇    下一篇

无黏性土中筒型基础负压下沉模型试验

祁 越1, 2,刘 润1,练继建1   

  1. 1. 天津大学 水利工程仿真与安全国家重点实验室,天津 300072;2. 天津市市政工程设计研究院,天津 300051
  • 收稿日期:2016-01-28 出版日期:2018-01-10 发布日期:2018-06-06
  • 作者简介:祁越,男,1990年生,硕士,主要从事岩土工程方面的研究。
  • 基金资助:

    创新方法工作专项(No. 2016IM030100);国家重点基础研究发展计划(973计划)(No. 2014CB046802)。

Model test of bucket foundation suction installation in cohesionless soil

QI Yue1, 2, LIU Run1, LIAN Ji-jian1   

  1. 1. State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China; 2. Tianjin Municipal Engineering Design & Research Institute, Tianjin 300051, China
  • Received:2016-01-28 Online:2018-01-10 Published:2018-06-06
  • Supported by:

    This work was supported by the Innovation Method Fund of China (2016IM030100) and the National Key Basic Research Program of China (973 Program) (2014CB046802).

摘要: 筒型基础是海洋结构物特别是海上风力机的重要基础型式之一,其下沉阻力的研究是该种基础型式成功应用的关键。目前对于无黏性土中下沉负压的计算方法主要有以静力触探为基础的(CPT-Based)方法与基于贯入过程中筒体受力平衡的解析方法,但计算结果与工程实测数据均存在偏差。开展了3种不同厚径比筒型基础的负压下沉模型试验,测量了下沉过程中筒内外侧壁、端部土压力以及周围土体的孔压变化;分析了2种方法中计算参数对结果的影响,给出了推荐的参数取值范围;根据实测孔压与数值模拟结果建立了临界负压计算公式。研究表明:砂土中筒型基础负压下沉时筒土间摩擦系数约为0.2,推荐CPT-Based方法中的外侧摩阻力系数为0.002 6~0.007 0,内侧摩阻力系数为0.001,端阻力系数为0.2~0.6;解析法中侧向土压力系数介于静止土压力系数与被动土压力系数之间,端阻力承载系数为40;考虑土体渗透破坏保护机制的临界负压计算公式可以有效地提高筒型基础下沉控制的临界负压,更加接近实际情况。

关键词: 海上风电, 筒型基础, 下沉阻力, 临界负压

Abstract: Bucket foundation is an important foundation type of offshore structures, especially for offshore wind turbines. Study on its penetration law is the key to successful application of this kind of foundation type. Previous methods for penetration suction are CPT-Based method and analytical calculation method, which are based on cone penetration test (CPT) and force balance in the penetration process, respectively. However, results from previous methods deviate from practical engineering data. In this paper, three bucket foundations with different wall thicknesses were penetrated by suction pressure. Earth pressure and pore pressure inside and outside the bucket wall, as well as the tip resistance were measured in the experiments. The influence of key parameters on the two calculation methods was analyzed and reasonable suggestions were given. According to measured pore pressure compared with numerical simulation analysis, a critical pressure calculation formula is established. Studies have shown that coefficient of friction between side wall and the soil is about 0.2. For CPT-Based method,outside-wall friction parameter kf is in the range of 0.002 6? 0.007 0;inside-wall friction parameter kf is 0.001; tip resistance coefficient kp is in the range of 0.2?0.6. For analytical calculation method, lateral earth pressure coefficient K should be between the stationary earth pressure coefficient and passive earth pressure coefficient, and tip resistance coefficient Nq is 40. The critical suction pressure formula based on protection mechanism for seepage failure can effectively increase the critical suction pressure,which is close to the actual situation.

Key words: offshore wind turbines, bucket foundation, penetration resistance, critical suction pressure

中图分类号: 

  • TU 411

[1] 马文冠, 刘 润, 练继建, 郭绍曾. 粉土中筒型基础贯入阻力的研究[J]. 岩土力学, 2019, 40(4): 1307-1312.
[2] 周和祥, 马建林, 张凯, 罗朝洋, 杨柏, . 沉井下沉阻力离心模型试验研究[J]. 岩土力学, 2019, 40(10): 3969-3976.
[3] 丁红岩,贾 楠,张浦阳, . 砂土中筒型基础沉放过程渗流特性和沉贯阻力研究[J]. , 2018, 39(9): 3130-3138.
[4] 练继建,马煜祥,王海军,王芃文,蒋杏雨, . 筒型基础在粉质黏土中的静压沉放试验研究[J]. , 2017, 38(7): 1856-1862.
[5] 刘 润 ,祁 越,李宝仁,练继建,丁红岩,. 复合加载模式下单桩复合筒型基础地基承载力包络线研究[J]. , 2016, 37(5): 1486-1496.
[6] 柳国环 ,练继建 ,王鸿振 ,于通顺,. 水动力质量实效施加方法及地基-筒型基础-塔筒体系的地震敏感性研究[J]. , 2016, 37(3): 767-775.
[7] 练继建,贺 蔚,吴慕丹,王海军. 带分舱板海上风电筒型基础承载特性试验研究[J]. , 2016, 37(10): 2746-2752.
[8] 于通顺 ,练继建 ,齐 越 ,王鸿振,. 复合筒型风电基础单向流局部冲刷试验研究[J]. , 2015, 36(4): 1015-1020.
[9] 于通顺, 王海军. 循环荷载下复合筒型基础地基孔隙水压力变化及液化分析[J]. , 2014, 35(3): 820-826.
[10] 杨 旭,陈 飞,练继建,王海军. 考虑挤土效应的筒型基础沉放阻力数值分析及试验验证[J]. , 2014, 35(12): 3585-3591.
[11] 闫澍旺 ,霍知亮 ,孙立强 ,刘 润 . 海上风电机组筒型基础工作及承载特性研究[J]. , 2013, 34(7): 2036-2042.
[12] 荣 冰,张 嘎,王富强. 响水海上风机群桩基础变形特性的有限元分析[J]. , 2010, 31(S2): 470-474.
[13] 王元战,肖 忠,迟丽华,谢善文,李元音. 筒型基础防波堤稳定性简化计算方法[J]. , 2009, 30(5): 1367-1372.
[14] 王 媛,李冬田. 长江中下游崩岸分布规律及窝崩的平面旋涡形成机制[J]. , 2008, 29(4): 919-924.
[15] 丁红岩,刘建辉. 钻井船拔桩对筒基平台稳定性影响的敏感分析[J]. , 2007, 28(6): 1205-1211.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!