Rotating Equipment: Foundation Post-Pouring Concrete Inspection

This inscription is written to be a general guidelines for site rotating engineer to inspect the foundation prior equipment erection/installation.

After the civil team finish with the concrete pouring activity, it is recommended for the civil team to make Foundation Work Release Notice or Foundation Handover from civil to mechanical rotating. There are several items that the mechanical team should give some attention to, prior accepting the foundation, which will be discussed further below.

Foundation Handover Document

This handover document is necessary to keep the split of responsibility between the civil and mechanical team. For example, if there is still defect found prior to handover to mechanical team, then it is still the civil responsibility to repair the defect. Then, to identify whether the foundation is defectless or not, the mech rotating team should do two kinds of inspection, which are:

 

1.     Foundation centerline inspection

     This inspection is generally the same with the pre-pouring concrete inspection. To help with the inspection, I recommend to use a simple string/wire to mark the location. 

     The items that needed to be concerned with are:

• The coordinate of the foundation centerline
• The size of the foundation (length, width, diagonal)
• The  elevation of the TOC (top of concrete)
• The size of the anchor box (length, width, depth)
• The relative position of the anchor bolt
• The elevation of the anchor bolt (if using embedded anchor)

2.     Padding plate and Anchor Elevation check

This inspection adjective is to check the padding plate position and level, the tools that usuallty used in this inspection is an Auto Level Topcon. The items that needed to be concerned with are:

• The elevation of padding plate is correct and within  tolerance (+-3mm)
• The padding plate height shall not exceed 100mm relative from the Top Of Concrete
• The position of the skid is need to be considered during the setting position of the padding plate

If there are any defects found during these two inspection, then it is still the civil responsibility to repair it.  After both of the inspections are finish, then the foundation is good to go. 

The Foundation Handover Document pre-requisite documents are as follows :

1.     Pre-Pouring Inspection Report

2.     Concrete Compressive Test Report

3.     Foundation Centerline Inspection Report (witnessed by mech rotating team)

4.     Padding Plate and Anchor Elevation Check Report (witnessed by mech rotating team)

Please be aware that the common curing time for concrete is 28 days, so the equipment can be installed after 28 days, unless the civil team were using curing additive to their concrete mix. After Foundation Handover Document is signed by both parties (civil & mech rotating) then we can continued to prepare the next step.

Rotating Equipment: Foundation Pre-Pouring Concrete Inspection

This inscription is written to be a general guidelines for site engineer to inspect the foundation prior equipment erection/installation.

The best way to solve a problem is by preventing it. Perhaps this will be a little discomforting, considering that it is not at all a rotating engineer’s job to inspect the result of bekisting/formwork prior the concrete pouring.

Rotating engineer VS Civil engineer

The civil and rotating engineer have a very fundamental difference. Rotating engineer usually talks in micrometers while the civil engineer talks in centimeters.

In some case, to avoid any dispute regarding the foundation, it is recommended for the rotating engineer has more involvement in the foundation inspection activity.

I have experiences when the civil works is not satisfactory because the anchor holes position is deviated too far, the level is not right and anchor box size is not sufficient. This deviations were causing the corrective action to be very time consuming and costly.

Hence, to avoid the same mistake happening again, it is recommended that the rotating engineer is more involved in the pre-pouring concrete inspection.

Pre-requisite Documents

The pre-requisite documents used as reference on pre-pouring inspection are as follows:

1.     Plot plan drawing

2.     Foundation drawing

3.     Equipment general arrangement drawing

4.     Civil foundation standard drawing

5.     Inspection Checklist

Important Aspects

The aspect that needed to be focused on by rotating engineer on pre-pouring inspection are as follows:

1.     The coordinate of the foundation centerline

2.     The size of the foundation (length, width, diagonal)

3.     The  elevation of the TOC (top of concrete)

4.     The size of the anchor box (length, width, depth)

5.     The relative position of the anchor bolt

6.     The elevation of the anchor bolt (if using embedded anchor)

The deviation of the measurement shall not exceed 3 mm, while for anchor bolt position the deviation for each anchor position shall not exceed 1.5 mm.