Friday, February 22, 2013

How to estimate earthwork construction period.

How to estimate the duration required to complete Earthwork Excavation? Estimation on the numbers of days required to complete the task by utilisation of machinery does not required complex calculation. All it take is simple mathematics and some knowledge on the efficiency of  machine capability.  Below is an example of the calculation.

1. Quantity of the Earthwork Excavation = 1000 cu.m.
2. The machinery needed = Excavator and Lorries 
     Assumption : 1 no. of Excavator and 1 no. of lorry required.
                        : Excavator need 3 minutes to make a cycle of excavation works.
                        : Excavator Capacity = 1.5 cu.m
                        : Lorries capacity =  10 ton
                        : Lorry need 5 minutes to make a cycle of transportation.
                        : Specific Gravity of the earth = 2.7

Base on the assumption, the calculation is as follows;
         a) Duration required to fill a 10 ton lorry 
              : 10 ton lorry bucket capacity = 10/2.7 = 3.7 cu.m
              : cycle require to fill the lorry bucket = 3.7/1.5 = 2.4666 Cycle or 3 cycle.
              : hence, time required for filling the lorry = 3 cycle X 3 minutes = 9 minutes

         b) Duration required for lorry to complete a cycle of transporting and unloading =5 minutes
              : Therefore total  time taken for one cycle of earthwork = 9 minutes + 5 minutes = 14 minutes.
              : 14 minutes is required to complete 3.7 cu.m of earthwork.

         c) Duration required to complete 1000 cu.m earthwork;
             : 1000 cu.m / 3.7 cu.m = 270.27 cycle = 271 cycle.
             : hence, time require to complete 1000 cu.m earthwork = 271 cycle X 14 Minutes = 3794 minutes
            
         d) Number of working hours per day = 8 hours
             
         e) Convert the Duration in minutes into days;
             : 3794/ (8 X 60) = 7 days.

Therefore total number of days to complete the 1000 cu.m of earthwork (cutting and cart away for a short distance) by utilised 1 number of excavator and 1 number of 10 ton lorry is 7 days. Hence your construction period is only 7 days. However this example is excluding number of unworkable day due to rain.

If the number of lorry is going to be increase to 2 then some correction can be make to the duration required to complete the whole cycle by by 5 minutes. this is because the waiting time for the excavator can be reduce by 2.5 minutes each for both lorry. Therefore the complete cycle can be consider as 9 minutes only.

With this free example hope that you will have nice time to plan for your earthwork construction.
               


Friday, February 8, 2013

RFI (Request for inspection) sample

REQUEST FOR INSPECTION
CONTRACT NO:
PROJECT TITLE:

REFERENCE NO:
DATE:
TO:
ATTENTION:

ACKNOWLEDGE RECEIPT BY:

DATE:


We hereby request for inspection on :
For the following work:(Tick in the box below (√))

BUILDING WORK
Boundary setting out

Building setting out

Setting out ( specify):
earthwork

Foundation

Beam

Column

Staircase

Reinforcement

Formwork

Roof truss

Slab

Perimeter drain

Apron slab

Wall/partition

Roof covering

Door frame

Door leave

Window frame

Window leave

Rain water drain Pipe

Gutter

Plastering

Painting

Floor Screeding

Floor tile

Wall tile

Water Proofing

Septic tank

Other :

CIVIL WORK
Earthwork

Road subgrade

Road sub base

Road base

Sewage manhole

Waste water manhole

Drain Alignment

Road Alignment

Road side drain

Flexible Pavement

Fencing

culvert

Road kerb

Road Marking

Signages



Mechanical & Electrical works
Internal water pipe

External Water pipe

Water tank

switches

conduit

wiring

Power point

Lighting

Lightning arrester

MCB

DB

MSB

Cold water fitting & accessories

Electrical fitting & Accessories

Other:



Location:
SO/SOR/RE/COW
The above work inspected on :
Inspected by:

Witness By Contractor:
Signature:
Date:
Approved (      )                  Not Approved (      )

Remarks:










Related Topic:
RFI
Request For Information 2010
Request for information form 2012
Inspection form for reinforcement installation
Document control and Correspondance Document Register
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