TRIAL PLAN A TRIAL PLAN B
FIRST PLAN
100%
EL CENTRO (1940)
TOKYO (1956)
·OSAKA (1963)
SEATTLE (1949)
NAGOYA
(1963)
MEXICO (1962)
0
1
2
3
4
→ T(sec)
Fig. 3. Acceleration spectrum (Dr. K. Muto)
k
q
Q(ton)
REMARK
0.217
0.217
2040
0.100
/0.15}
9700
0.228
0.228
2160
ZZA
0.075
0.075
6600
0.07 0.28
0.28
792
|0.04 0.170.25
0.052
3940
0.25
805
0.0475
3930
Analized by
ANALOG Computer Box type Column
Box type Column
Analized by DEGITAL Computer Cross type Column
Analized by DEGITAL Computer H Type Column
Fig. 4. Transition of planing conditions in forces on columns in respective shapes of column section
180 miles per hour, that is 80 m sec.
On September 16, 1961. the second Muroto Typhoon registered a maximum instantaneous velocity of 84.5 m/sec. at Cape Muroto. But as this observation point is situated 227 metres above sea level, the value is too severe to be applied to city
streets.
Judging statistically from the data. produced in Tokyo area over the past eight years, the expectation of the maximum instantaneous velocity for the period of 200 years is 68.5 m/sec. For extra safety a wind design of 75 m. sec. was adopted.
Assuming the maximum instantane- ous velocity is 75 m sec., the wind load is determined by the following Bernoulli equation for the curtain wall and window glass.
P 1/2 p V2
According to investigations by Dr. H. Arakawa*, city winds have pecu- liarities such as strong gusts at a height of about 70 metres above ground in Tokyo. This may be due to the phenomenon that when a typhoon blows above a
group of buildings of about 30 metres height, eddies are formed in the space be- tween buildings, which then disinte- grate into instantaneous upward streams in the space above the build- ings.
Large Size H-Shape Steel
The mean structure of the Kasumi- gaseki building comprises a steel frame which is light in weight and high in ductility, The conventional steel frame is made by the so-called built- up system: that is by welding or rivet- ting together plates and angles. But for the Kasumigaseki building, it was necessary to use steel elements of large section and large thickness, which were unsuitable for the built- up system, because the welding length is longer and the number of proces- sing works in the factory is increased.
It was decided to use H-shape steel of wide flange for columns and beams.
* Director of Meteorological Observatory
44
A
B
to
S(cm2) W(kg/m) I (cm4) Iy (cm4) ix (cm)
iy (cm) Z (cm3) Zy (cm3)
398
400
13
20
210.7
165
418
407
20
30
320.0
251
63,400
108,000
438 412
25
40
423.3
332
O 458 417
30
50
528.6
415
478 427
40
60
659.8
518
478
437
50
60
707.6
555
478
447
60
60
755.4
21,300 17.4
33,700 18.4 142.000 46,700 18.3
187,000 60,500 18.8 242,000 78,100 19.1 251,000 83,900 18.1 593 260,000 89,300 17.7
10.1
3,190
1,070
10.3
5.160
1,660
10.5
6,470
2,170
10.7
8,170 2.900
10.9
10,000 3,660 10.9 10,500 3,840 10.9 10,900 4,030
Note: Materials marked ◇ actually used.
t
t2
B
Fig. 5. Table of structural dynamic details. H-type steel
Far East Architect & Builder November, 1967