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.
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
.
DOI: 10.3969/j.issn.1001-909X.2019.01.009
[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.
