黏性土淹没射流破土实验研究

郑健; 来向华; 陈小玲; 李冬

doi:10.3969/j.issn.1001-909X.2019.01.009

PDF(2849 KB)

海洋学研究 ›› 2019, Vol. 37 ›› Issue (1) : 67-74. DOI: 10.3969/j.issn.1001-909X.2019.01.009

研究论文

黏性土淹没射流破土实验研究

郑健, 来向华, 陈小玲, 李冬

作者信息 +

Experimental research on mechanism of soil breaking by submerged jets in clay

ZHENG Jian, LAI Xiang-hua, CHEN Xiao-ling, LI Dong

Author information +

文章历史 +

摘要

海底水力喷射开沟技术在海底管道、光缆埋设等工程中得到广泛应用,然而黏土尤其是硬质黏性土中的水力开沟施工较为困难,为阐明其中的破土机制,开展了二维垂向淹没射流开沟物理模拟实验。通过观察射流破土的过程,发现:软黏土与硬质黏性土中冲坑发展的特点有所不同,破土机制也存在差异。射流对硬质黏性土的破坏中,压力导致的剪切破坏起到很大作用,在土力学原理上近似于地基土整体剪切破坏,据此建立了硬质黏性土射流破土模型,同时提出冲坑颈口直径在硬质黏性土冲坑形态中的重要性,并以此取代原有的冲坑直径作为一个预测指标。

Abstract

Hydraulic jet trenching technology has been widely used in submarine pipeline and optical cable embedding engineering. However, jet trenching construction in stiff clay is difficult. In order to elucidate the mechanism of soil breaking, the physical simulation experiment of submerged vertical jet trenching was carried out. During the process of soil breaking, it is found that there are some differences between the development characteristics of scour hole in soft clay and stiff clay. Shear-compression stress is the main factor of soil breaking in stiff clay and the breaking mode in stiff clay can be explained by the Prandtl foundation ultimate bearing capacity theory. Based on this, the model of jet to break hardpan is established, and the diameter of hole's neck is proposed to replace the diameter of scour hole as a prediction index.

导出引用

郑健, 来向华, 陈小玲, 李冬. 黏性土淹没射流破土实验研究[J]. 海洋学研究. 2019, 37(1): 67-74 https://doi.org/10.3969/j.issn.1001-909X.2019.01.009

ZHENG Jian, LAI Xiang-hua, CHEN Xiao-ling, LI Dong. Experimental research on mechanism of soil breaking by submerged jets in clay[J]. Journal of Marine Sciences. 2019, 37(1): 67-74 https://doi.org/10.3969/j.issn.1001-909X.2019.01.009

中图分类号： P754

参考文献

[1] RAJARATNAM N, BELTAOS S. Erosion by impinging circular turbulent jets[J]. Journal of the Hydraulics Division, 1977, 103(10):1 191-1 205.
[2] MAZUREK K A,HOSSAIN T.Scour by jets in cohesionless and cohesive soils[J].Canadian Journal of Civil Engineering,2007,34(6):744-751.
[3] MAZUREK K A,RAJARATNAM N,SEGO D C.Scour of cohesive soil by submerged circular turbulent impinging jets[J].Journal of Hydraulic Engineering,2001,127(7):598-606.
[4] DUNN I S. Tractive resistance of cohesive channels[J]. Journal of Soil Mechanics and Foundation Division, ASCE, 1959, 85: 1-24.
[5] NOBEL A J, TALMON A M, VLASBLOM W J. Cavitating jets for dredging clay[C]//The 17th International Conference on the Hydraulic Transport of Solids, 7-10 May, 2007, Cape Town, South Africa.
[6] HO C E. Turbulent fluid jet excavation in cohesive soil with particular application to jet grouting[D].Massachusetts: Massachusetts Institute of Technology, 2005.
[7] MACHIN J, MESSINA F, MANGAL J, et al. Recent research on stiff clay jetting[C]//Offshore Technology Conference, 2001.
[8] GU Lei, NI Fu-sheng, ZHANG Hao. Numerical calculation of jet scouring in sand and clay based on ALE method[J]. Science and Technology and Engineering, 2017, 17(11):103-107.
顾磊, 倪福生, 张浩. 基于ALE方法的射流冲刷砂土和黏土的数值计算[J]. 科学技术与工程, 2017, 17(11):103-107.
[9] ZHANG Shu-sen. Experimental research on trenching in stiff clay by submerged vertical traveling jets[J]. Journal of Coastal Research, 2016, 32(2):365-373.
[10] MA Fei, SONG Zhi-hui. Dynamic characteristics of water jet flow and the failure mechanism of soils[J]. Journal of University of Science and Technology Beijing, 2006,28(5):413-416.
马飞,宋志辉.水射流动力特性及破土机理[J].北京科技大学学报,2006,28(5):413-416.