NUMERICAL SIMULATION AND ANALYSIS OF INTERFERENCE EFFECTS ON THE PORT CONTAINER GROUP

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1 NUMERICAL SIMULATION AND ANALYSIS OF INTERFERENCE EFFECTS ON THE PORT CONTAINER GROUP Chun-hui Zhang, Wei Sun, Xing-qian Peng Graduate student, College of Civil Engineering, Huaqiao Universit, Quanzhou, Fujian, China, 360, Professor, College of Civil Engineering, Huaqiao Universit, Quanzhou, Fujian, China, 360, ABSTRACT Through numerical simulation of strong wind-induced overturning interference effect on -pile & 3-pile container group, the regular pattern of container group overturning critical wind speed interference factor following the change of spacing laers is described in detail. Meanwhile, a comparison of interference factor of -pile container group and that of 3-pile is made. The results of this paper could provide some related references for container group laout optimization and stud of anti-tphoon of large container group ards. KEYWORDS: CONTAINER GROUP; OVERTURNING; NUMERICAL SIMULATION; INTERFERENCE FACTOR Introduction Among tphoon-causing propert damages and casualties, structural damage and collapse constitute a high proportion. In view of serious consequences of windstorm, stud of structure anti-wind is alwas the emphasis of disaster prevention and reduction research. A lot of researches in wind-resistant of structure have been done at home and abroad, man results have been obtained. Most of previous research focused on building structure bridge structure etc, however, studies of port container group are seldom seen. Container group ards are seriousl influenced b the tphoon, blowing over and sliding of container crane & container are commonl seen. On September 9th 996, Zhanjiang port of Guangdong was devastated b tphoon, 6 cranes were destroed and most of them were blown over b tphoon. In 003, Tphoon Rhododendron with maimum wind grade of landed in Shenzhen. 7 empt containers in Chiguang Gulf were blown over. Furthermore, 00 containers in container terminal of Yantian Port were also blown over and destroed, though reinforcement measures had been made [Zhao et al. (008)]. Analsis of container overturning In order to keep the stabilit of container against strong tphoon, the should meet the following two conditions:. Horizontal wind force must be less than the maimum static friction of container.. The moment which is induced b wind pressure acted on one side of container must be less than that induced b gravit. Thus the following formula could be obtained:

2 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan F + F ( G + F )μ () h b h a F + m ± ( G Fz ) 0 & F m ± ( G Fz) 0 () Among them, P(,, z) is the wind pressure at point (,, z), F F Fz mean concentrated force around X Y Z ais under wind load respectivel, M M Mz mean moment around X Y Z ais under wind load respectivel (Fig.). μmeans the maimum static friction coefficient of container, the value is 4 in general,g means the self weight of container. A common international comparison of 40-foot high (.8m.3m.7m) container in this paper, its dead weight is 4.t. z h b h b F + F = + ±, M = F m ± Fz, FL = - Fz μ M F m Fz To facilitate comparisons, the horizontal force coefficient could be epressed as: FL μ L = (3) ρν Overturning moment coefficient around X ais could be epressed as: M μ = (4) ρν H Overturning moment coefficient around Y ais could be epressed as: M μ = (5) ρν H Substitute formula(3)into formula()and get the following critical wind speed: B C E Fig. Wind angles F Fz 0 Fig. Forces of container F z z D A ν = G L ρμ (6) L Substitute formula (4) and formula (5) into formula () and also get the following critical wind speed: ν ν G b = (7) ρhμ G a = (8) ρhμ Then critical wind speed is ν p =min{ ν L ; ν ; ν } (9)

3 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan ρ is the air densit (.5kg/m 3 is selected as ρ when the temperature is 5),ν is wind velocit at reference point, H means reference height, ν L means critical wind velocit when horizontal force-induced instabilit, ν means critical wind velocit when around the X-ais overturning, ν means critical wind velocit when around the Y-ais overturning. Numerical wind-tunnel simulation. Basic equation and turbulence model Time mean simulation method which will be solved b turbulence model close controlling equation is adopted in this paper. Due to the mutual interference among building groups and anisotropies flow in wind field [Li (004)], chose k-ε RNG turbulence model accordingl. General form of air flow controlling equation is [Yang et al. (004) and Murakami et al. (988)]: ( ρϕ) + div( ρϕ u ) = div( Γgradϕ) S (0) t In the above equation, the four parts respectivel mean transient term convection term diffusion term and source term,ϕ is the generic variable, Γ is generalized diffusion coefficient, S is generic source item.. Boundar condition Setting () Entr: The initial wind profile is described b power law u(z)=u 0( Z / Z 0) a, where U0 is the wind speed at m above the ground [Zhou (005)], a=0. under the terrain A. () Eport: Full developed turbulence and developed flow boundar condition used. [Qiao et al. (008)]. (3) Adopt smmetrical boundar conditions on top and both sides of flow field, is equivalence to the free sliding wall; while no-slip wall conditions is adopt in the building models surface and on the ground [Zhang et al. (003) and Sakamoto et al. (988)]..3 Computational grid In order to meet the requirement of the model, tetrahedron discrete grids with good adaptabilit have been adopted. In order to obtain better simulation of wind flow characteristics in the domain, the grids near the model is ver small and the distribution is densel. On the contrar, remote grids are ver large and the distribution is sparse [Xie et al. (003)]. 3 Analsis of the results The interference factor IF generall describes the interference effect quantitativel, this tet emploed IF to describe interference effect of building groups [Xie et al. (004) and Xie et al. (006)]: Vmin I IF = V min A ()

4 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan V min I and V min A mean critical wind velocit at multi-containers ards and single container ard respectivel. 3. Two piles of container group 30 Fig.3 Diagrammatic sketch of container Fig.4 Laout of two & three piles, wind directions As shown in Fig.4, the nd pile is located at upwind, which would cause shelter effect [Xie et al. (006)] on the st pile. The critical wind velocit of the nd pile is less than that of the st pile. So the following interference factor is chosen from the nd pile. As shown in Fig.5, the interference factor is less than, which means critical wind velocit is less than that of single-pile container group. ()Laer number: Among different spans, interference factor will become small with the addition of laer number. That means overturning critical wind velocit of containers decrease with the increase of laer number. ()Rows: When the span is equal to 0.6m, the interference factor of - containers reaches maimum, the factor of - container takes the second place. The factors of are close to each other. The critical wind velocit of - containers comes nearest to the critical wind velocit of single-pile. When the span is respectivel equal to 3m 6m 0m, interference factor increases with increase of the number of s. Critical wind velocit of containers comes nearer to single-bundle critical wind velocit. (3)Span: From Fig.5-e, interference factors of increase with the increase of span, which indicates that interference becomes non-obvious with the increase of span and will come near to that of single-pile container. 3. Three piles of container group Span of three piles of container group is 0.6m respectivel. () Impact on container group with different laer numbers As shown in Fig.6, all conditions of 8- container group are listed as below. The interference factor of st pile is the largest, the factor of the 3 rd pile is the least, that means the critical wind velocit of st >the critical wind velocit of nd >the critical wind velocit of 3 rd. In all conditions, interference factor of st is alwas bigger than, which means critical wind velocit of st is more than that of single-pile containers; is increasing from a laer to two laers, the interference factor is decreasing with the increase of la number above Laers, the decreasing trend above 6 laers becomes slightl. The changing law of nd pile is ver similar to that of st pile, the interference factors of 6 laers 7 laers 8 laers are all less than ; s of 3 rd in all conditions are all less than, that means critical wind velocit is all less than that of single-pile container, these are all unfavorable interference. Attention should be aroused. From Fig.7, interference factors of st & nd in all conditions are alwas more than, the factors is increasing from a laer to three laers, and the factors are decreasing with increase of la number above 3 laers. The changing law of interference factor of 3 rd pile is ver similar to that of 8- container group. 3

5 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan From Fig.8, Interference condition of 6- is ver similar to that of -. So the change in the law of 3-pile container group is similar to that of -pile container group Laer number 4C 5C 6C 7C 8C (a)d=0.6 m C 5C 6C 7C Laer number 8C (b)d=3 m Laer number 4C 5C 6C 7C 8C C 5C 6C 7C Laer number 8C (c)d=6 m (d)d=0 m.0 4C 5C 6C 7C 8C 4C 5C 6C 7C 8C 4C 5C 6C 7C 8C 4C 5C 6C 7C 8C 4C 5C 6C 7C 8C Laer and Row s 4 s 8 s s 一排两排四排八排十二排 0.6 m 3m 6m 0m (e) different span different different floor height Fig.5 of -pile container group at different conditions The change law of the critical wind velocit interference factor of 3-pile container group with the change of s & spacing is similar to that of -pile container group. It is no longer illustrated in the paper. () Interference effect of container group in different bundle In order to analze comprehensivel overturning interference effect of 3-pile container group in strong wind, interference factors of each pile container group are studied in this paper.

6 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan Interference factor.5.3. c c c3 c4 c5 c6 c7 c8 3 Laer nunmber Fig.6 s of 8- in 3-pile container group Interference factor c c c3 c4 c5 c6 c7 c8 Laer number Fig.7 of - in 3-pile container group c c c3 c4 c5 c6 c7 c8 Laer number Fig.8 of 6- in 3-pile container group ) The first pile of container group The first pile is located in downwind direction, from Fig.9, all interference factors are all bigger than, and overturning critical wind velocit is more than that of single-bundle container. In the same la number, interference effect of 6- is ver obvious and critical wind velocit is the maimum, - takes the second place, 8- is the least. In the same, interference factor is increasing with increase of laer number below 3 laers. And the interference factor is decreasing above 3 laers. ) The second pile of container group The second pile is in the middle of container group. The pile with different has different interference effect accordingl. of 6- - is more than respectivel, which epress shelter effect and critical wind velocit is more than that of single-pile container group. With regard to 8-, interference factor is also less than above 5 laers and the critical wind velocit is more than that of single-pile container group, unfavorable effect arises. Total changing law is similar to that of bundle. (Fig.0). 3) The third pile of container group The third pile is located in upwind direction; interference factor is less than generall. It s epressed as unfavorable interference effect. is decreasing with the increase of laer number above laers, and the decreasing trend becomes flat above laer 6 (Fig.).

7 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan Interference factor c c c3 c4 c5 c6 c7 c8 Laer number Fig.9 of the st pile with different Interference fator.6.4. c c c3 c4 c5 c6 c7 c8 La number Fig.0 of the nd pile with different Interference factor.. c c c3 c4 c5 c6 c7 c8 La number Fig. of the 3 rd pile with different Conclusions Numerical simulation and analsis of interference effects on the port container group were carried in this paper, and the following conclusions are obtained for related personnel reference. () In general, the overturning critical wind velocit of -pile container group is less than that of single-pile container group, and overturning critical wind velocit of 3-pile container group is more than that of single-pile container group. () Overturning critical wind velocit of container group located in upwind direction is ver small generall. (3) With the increase of la number, the overturning critical wind velocit of container group is decreasing. And decreasing trend graduall becomes mildl above 6 laers. With the increase of the number of, the overturning critical wind velocit is increasing. With the increase of span, the overturning critical wind velocit graduall comes near to that of single-bundle container group. Acknowledgements This research is supported b the following projects: the National Natural Science Foundation of China under Grant No , the Fujian s Science and Technolog

8 The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan signal special project under Grant No. 005YZ06, the Xiamen s Science and Technolog universit innovation project under Grant No. 350Z , the Quanzhou s Science and Technolog planned project under Grant No. 007G7. References Li W. P. (004), Computational Fluid Dnamics, Huazhong Universit of Science and Technolog Press, Wuhan, Murakami S. and Mochida A. (988), 3-D numerical simulation of air-flow around a cubic model b means of the k-ε model, Journal of Wind Engineering and Industrial Aerodnamics, 3(), QIAO Chang-gui, PENG Xing-qian, ZHAO Qing-chun. (008), Research on the computational domain setting of the numerical simulation about the harbor container groups, Journal of Zhengzhou Universit of Light industr, 3( ):04~07. Sakamoto H. and Haniu H. (988), Aerodnamic forces acting on two square prism placed verticall in a turbulent boundar laer, Journal of Wind Engineering and Industrial Aerodnamics, 3(), Xie Z. N., Gu M., Ni Z. H. (003), Eperimental stud of wind load on three square prisms side-side of arrangements.journal of Xi an Jiao Tong Universit, (37)3:90~93. Xie Z. N., Gu M. and Ni Z. H. (006), Quantitative analsis on mean interference effects of tall buildings, Journal of Harbin Institute of Technolog, 38 (), 49~5. Xie Z. N., Gu M. and Ni Z. H. (004), EXPERIMENTAL INVESTIGATIONS ON STATIC INTERFERENCE EFFECTS OF TALL BUILDINGS, China Civil Engineering Journal, 37 (6), 6~. Yang W.,Huang P.,Gu M. (004), Eperimental and numerical stud on wind- induced mean interference effects o n two tail buildings, Journal of Tong ji Universit, 3 ( ):5-l56 (In Chinese). Zhao Q. C., PENG X. Q., QIAO C. G., SHI L. L., ZHOU X. P., (008), Overturning resistance calculating of harbor containers under the strong-wind, Journal of Zhengzhou universit of light industr (Natural Science) 3(4): Zhou D. W.(005), Stud of Stead-state of Wind Load & Field and large-edd simulation for Tall buildings, Master Degree Thesis of Aerospace and Mechanics Institute, Tongji Universit. Zhang X., Qi H., Xiao W.(003), Numerical Simulation of Wind Pressure Distribution on Xiamen International Conference and Ehibition Center, Structural Engineers, 0(4), 3-36.