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RE: 4-storey design

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Dear Sir,

	First of all, I do not have a permanent address at Toyota so I use
the e-mail of my partner, Francis Ang.
	Anyway, I know Stella Sabiniano and Rannie Ison. Rannie and Boss
Nick have left EHSEC for good. The last time I saw Rannie in EHSEC, that was
his last day I think. Stella left for US a few months ago. The combination
of Rannie, EHS and Nick was good. But that was then. I used to work at
EHSEC, with Rannie, Stella and Nick. 
	With regards to the building that I'm designing, I could be a little

confused with the tie spacing. I checked it against the actual shear that is
accompanying it and the results were pretty safe / conservative. 
	Don't worry with the application of EQ forces. I really design for
EQ running in both directions. When I was in EHSEC before, I used to design
lateral load acting in both directions but with a factor (say x 0.5 y 0.5). 
	With regards to the bar size, is there a structural implication
between 20mm and 25 mm bar size ? I know that using 25-mm bars would limit
the number of  bars in the column and would provide an ample amount of rebar
spacing. What is your comment on this ? Using similar sizes for the column
rebars is a good thing for construction purposes. Sometimes, in ordering,
installation and splicing, they would provide economy.
	I just need a little confirmation on things. Sometimes, other's
small opinion could be a big help. Thanks very much.
Allan Yango

> ----------
> From: 	Jerome.Tan(--nospam--at)[SMTP:Jerome.Tan(--nospam--at)]
> Sent: 	Thursday, June 10, 1999 4:12 AM
> To: 	Francis.Ang(--nospam--at)
> Subject: 	Re: 4-storey design
>      Francis,
>      I both know Apeng and Mayo. You might be familiar with Rannie and 
>      Stella, too.
>      See yor ACI 318-95 Chapter 21. That should help you.
>      And where in the code did you see the 150 mm limitation? Even if it 
>      does says so, this is only limited to where shear reinforcement is 
>      required. Where shear is effectively resisted by concrete you can go 
>      beyond the limit. For your girders and columns which are collectors 
>      follow ACI 318-95 ch. 21. Remember, read the codes and see what 
>      particular regions the limitations are required.
>      See ch. 21.3.3 to and 21.4.4 to
>      As for your column, I believe it looks Ok. but I would prefer having
> it 
>      square. Who says eqk comes in the E-W  direction only? A 400 x 400 or
>      450 x 450 looks fine. check your reinforcements. I would expect 25's 
>      there not 20's. If you like 20's, provide so from 2nd floor level 
>      upwards, not on the footing to 2ndf levels.
>      I was at Parsons before when i communicated with you earlier. Now I
> am 
>      with Fluor Daniel.
>      Hope this helps.
>      Jerome
>      ______________________________ Reply Separator 
>      _________________________________
>      Subject: 4-storey design 
> Author:  Francis.Ang(--nospam--at) at fdinet
> Date:    6/9/99 7:50 AM
> Dear Sir,
>         Right now, I'm involve in a design of a 4-storey residential
> structure. The east-west bays are in 3.2-2.5-3.2m center to center column 
> dist. and the north-south are in 5-4.24m spacing. The design was done in a
> fast manner with due care. I got a column of 500 x 350mm for the center 
> p-ost with 12-20mm. The architect said this was really large. I tried to 
> argue that the large column size was due to the large load it would carry 
> (like the water tank @ the rooftop, stairs with 125mm thick slab) and it 
> would carry much of the EQ forces since the 500mm dimension is along the 
> east-west direction. They said that for a seven storey building, they were
> only getting a 500x500 column.
>         I tried to review my loadings. I  computed the weight W with
> accuracy. I also assumed that the 800 gallons of water located at the 
> rooftop would add to the earthquake force. 
>         Am I right on my assumptions? Also, I computed the tie spacing as
> per ACI / NSCP Seismic provision. For the confinement region, I'm getting
> a 
> 50-mm tie spacing (10-mm bar). I am confused on the spacing of the ties / 
> hoops outside the confinement region. Code provision says it should not be
> greater than 150 mm. Don't you think this is to conservative? I specified 
> 200mm spacing of ties.
>         I hope you could guide me on this. An EQ struck my country
> yesterday
> at Agusan in Mindanao. I don't want my designs to fail in anyway even if
> no 
> lives are lost. 
>         By the way, I lost much of guidance from my bosses since Nick and
> Boss Apeng have parted ways. I feel like it's all by myself now not like 
> before when I was in the consultancy office.
>         Thanks.
>         Allan Yango
>         TMP