Total time reqiured for Office building...

Hi Mike,



Your right, top-down is not a viable option.



It is only a 3 storey bldg so the equipments are not that big. A trolley system using basement ramp could be used to install and remove the equipments. Another option is to assymble the equipments at the basement ex. chiller if any.





regards,

arman

Hi Armando



If there is no external access to the basement level 0 then obviously top down construction is not a viable option.



If the M&E plant is in the basement then check how they are going to get it in - and out again in 15 years time.



Best regards



Mike Testro

Hi Mike,



You mean top-down substructure construction?



It seemed to me that the difficulty in doing such scheme is that in this project, the superstructure foot print is even bigger than the substructure foot print.





regards,

arman

Dear Mike,



These projects are fun, I was part of a project recently and we were able to complete 6700m2 building (6 stories) with 18meter excavation in 6 months ($2 Million).



We have around 70 people at site working 20 hours a day with the necessary materials and equipment to complete the job. 3 Project Managers and steady finance.



With kind regards,



Samer

Hi Armando



If you can spring the columns from the pile caps or the raft you can work in level 0 as soon as level 1 is de-propped.



This allows drains and services and the basement slab and lift pit to be carried out concurrent with the structure.



This should take off 4 weeks.



Best regards



Mike Testro

Dear armando,



As long as you can secure the resources to site, I agree with you.



With kind regards,



Samer

Hi Samer,





I would use the following:



1 floor set of table forms

2 floor sets of back props

3 mobile cranes for erection (no tower crane)



with the above, the cycle could be 7 days/floor which gives us 42 days from B2 to RD but say 2 months for learning curve,etc.



As what Mike said, it is indeed a simple structure. I would prefer to have the shortest construction duration to significantly reduce the prelims cost.



regards,

arman

Dear armando,



That is very optimistic figure. You need to identify the resources with that.



With kind regards,



Samer

Guys, I would say...



1.Preparation and approval of priority shop drawings, bar bending schedules and delivery of first batch of rebar = 2 months from NTP

2. 1 month excavation works including final trimming to start 1 month from NTP

3.2 weeks blinding works (assuming raft foundation no piles) FS no. 2

4.Construct raft foundation 1 month SS no. 3 log 1 wk

5.Construct B2-B1 Columns and Retaining Walls 1 month SS no. 4 log 2 wks

6.Construct B1 Slabs and Beams 1 month SS 2 wks no. 5

7.Construct B1-GF Columns and Retaining Wall 1 month SS 2 wks no. 6

8.Construct GF Slabs and Beams 1 month SS 2 wks no. 7

9.The above shows total duration 4 months

10.L1 to Roof Deck= 2 months.

11.Total Civil/Structural Works duration is 6 months from NTP

12.Plumbing and Electrical SS no. 4 for 8 months

13.Mechanical and Fire Protection FS no. 6 for 6 months

14.Architectural Works 7 months FS no. no. 6 for 6 months

15.External Finishing Works and Landscaping 4 months FS 10

16.Total Project Duration is 9 months



As the duration becomes shorter, the prelims/overhead costs also becomes cheaper.





Mike, as I read your reply less than an hour ago, your comments regarding dangerous practice of a planning engineer is very much appreciated. However, maybe plenty or few members like me are excited to read what others have in their minds for this topic. And as the information flows freely I mean the replies, we could decide which information is likely to caught our attention or not.





Best regards,

Arman

Hi to All replies



When you list periods in weeks for various stages you are just guessing at top down durations - which is a dangerous practice.



You will not know the true duration until you have done a detailed bottom up critical path programme.



As I have said before in this forum the task should take little more that a day or two for a skilled planner and less than half a day for me.



Best regards



Mike Testro

Yes Mai t,



My analysis was excluding piling works and starting from pile chiping.....and the reasons i didnt include the roof was that i wasnt critical activity for starting finishing works......



regards



Haresh

Hi Haresh:



Your report has to show 2 work stages :

First one for foundation system : whether is piles with shoring works or whether is normal foundation , but whereas u have basement that mean shoring system will be applied and usually such system is required 6 months considering the factors which are mentioned by Samir .



And other stage for:

sub-structure : 3-4 months .

Super-structure : 2months .

Roof system :1 month.

Finishing with external packages 4 months since your building is offices.



The total will be; 15-16 months.



Regards .

Mai t.

Hi Ashutosh



2 basements and 3 storeys above - simple structure.



Why not take a day out and set up a simple bottom up programme to see how long it will take to build.



Best regards



Mike Testro.

Dear Ashutosh,



I like what Haresh has provided. But you need to keep in mind that you have productivity factors, soil conditions, environmental factors, unforseen conditions and most important, it depends on the Contractor’s team that is going to be complete the project.



18-24 months is a good range. The choice depends on the client requirement as well. If you push the time, then the Contractors will increase the cost because they have to bring in more resources. So I suggest that you call up few contractor in your region and see what estimates they give you.



With kind regards,



Samer

Total Duration reqd.



1)Foundation works - 80 days.

2) Basement- 2 - 45 days.

3) Basement - 1 - 30 days.

4) 3 Floors - 3X18 - 54 days.

5) Finishing works

after completion of - 210 days. (7 Months for office building)

Structure



Total reqd duration is = 420 days.i.e. 14 to 15 months, if the location is in Middleeast...