14 



: 





1 1 ' 



1 







"l " 







•| 





i 







■ 



' i ' 



" ! 



■■;-■ 



..:_. 









i 1 ; 



r 



i ■ 





- .1 i 







J..L 1 !.= !. 



_.j.. 





:-j:.: 



■ 



m 



_;... 



: 



,._..L.L 



__..,.. 



,_ 



12 



1 



— I = ul-|-ln(a ul.ll- 



H-- 



..... 



i 







..... 















"j 



; 





-4-!- 



--■ 



-!- 



a 



C D * 



..L.|..L. 



-i- 







._J_ 



-!;S 



:.l... 



! b 



/ ... 



10 



2V(1.C M ) 





..:.!.,. 











.:. I .:.. 



..... ., . ; . . 







.X..L, 









T'f- 



■ : 



! 











;;!.:.; 





■; 



, 





"~r^ 



;...!.:... 







■ r 



: 



rHI^K 





..., 





Distance, 

 I T 



-J-U 



..j.. 





-}- 



..j... 



•■pit 



■'-{-'- 



4- 



...;. 



-j -, 



■■.-j . 



/j... 



.xj:.j. 



:- 



(m) ' 

 6 



1 







" r' 



" 



! 1 ■ 



,LLk 



.:.;. ,..: 



■.--! 





..... |„.j 



...:..|._i 





— j — ■ 



.... .! ; 



.j... 



H 





' j 



r\- 



W 



! ./ 









1; 1 



;S\ '' 



I 











_,l,.. 



.h : 



. ;.| ! 





...j. 



i 



j \y 









■^v 



1 : 



'¥■: 



3 





__^ 



! I . 





1 ^ 



... j 



J<u:.: 

 ' • 1 



— 



i 



...1..I..J, 



>Hh-- 



I .. ..j... 





L...J 



- — 



! 

 > 



^p=. 



...;... 1.:. 



I^> 







:■ 



.,.,_ 



..;_!...;_ 





v> 1 ^^-- . 



1 .. 



■""•Tj; 



-1-1 — 



--■U- 



.;._ 





■^r 



_>-r ; 



\^S^T 











1 











— p- 



r ' 



..... 



.... 







! ! 



■i 1 i 



: = 















i..i 



, 



1 , 



.... 



i j... 



; 



' 



■.:.-.!; : i:. 



:iltJ 4" 



sg 



U=I4 m/« 



a =0.05 



u= 14 m/t 



a =o.02 1 



u= 10 m/s 



= 0.021 



02 



0.4 



0.6 



0.8 



1.6 



1.8 



2.0 



1.0 1.2 I 



Tunc, I (s) 



Figure 70. Example plots of x versus t for objects moved by tsunami surge. 



************* EXAMPLE PROBLEM 27 



************** 



GIVEN: A tsunami surge is 5 meters high at the shoreline. A building 

 located at the shoreline is swept forward a distance of 6.1 meters 

 and impacts with another building. The building is rectangular, 12 

 meters (39.4 feet) wide and 6 meters (19.7 feet) deep in the direction 

 of flow, and is submerged to a 3-meter depth as it is carried forward 

 (see Fig. 71). The velocity of the surge is approximated as u = 14 

 meters per second. 



FIND : 



(a) The time required for the building to impact with the other 

 building, 



(b) the force accelerating the building at the moment of impact, and 



(c) the momentum of the building at the moment of impact. 



SOLUTION : 



(a) The submerged cross-sectional area of the building, transverse 

 to the direction of the surge, is given as 



A = width x submerged depth = 12.0 x 3.0 = 36 square meters 



and the submerged volume (the displaced water) is 



V = width x length x depth = 12.0 x 6.0 x 3.0 = 216 cubic meters 



1 



