Holdfast Training Services Trial Blog

Introduction

After a few weeks working on site and a trip to Borneo it is time for a blog. I’m currently working for Brookfield Multiplex (BM) on One Blackfriars Road (OBR) in central London. BM specialises in constructing high rise buildings or in their own corporate words “We build skylines London/Dubai/Sydney…”.

Overview

BM are constructing a 50 storey residential tower to shell and core status, hotel including fit out and a 4 storey retail podium including all the Mechanical Electrical and Public Health (MEP). Below the entire site is a 3 storey basement which contains all the centralised building services, hotel swimming pool and some very expensive parking spaces.

Shell and Core Status

Shell and core for the tower comprises of the structure, façade, common areas, external works and base plant.

The base plant is mostly M&E and includes:-

1. High and low voltage switchgear.
2. Transformers.
3. Lift systems.
4. A standby generator.
5. Boilers.
6. Chillers.
7. Cooling towers.
8. Water and fuel tanks.
9. Sprinkler plant.
10. Building control systems.
11. Air conditioning chambers and fans.
12. Water and fuel pumps.
13. Dry risers.
14. Fire detection, alarm and hose reel systems.

The Client

The client is St George part of the Berkley Group and they are a very ‘hands on’ client with their own project management team on site to manage their own sub-contractors and BM (Principal Contractor). All communication for St George’s subcontractors has to go via the client, which makes it slightly more difficult for BM to effectively manage the entire site. St George are heavily involved  with significant developments requiring approval such as jumping the crane, site access and storage, and changing over the power supply from one substation to another.

Role

I have been given the role of Assistant MEP Site Manage and are responsible for managing the installation of the following systems within the Tower and Basement:-

• Condenser system.
• Domestic water.
• Wet riser system.
• Low temperature hot water.
• Low voltage power distribution.
• Heating, ventilating and air-conditioning system.
• Combined heat power.
• Lift systems.

Sectional Handover

The Tower is broken down into sections of 2 to 3 floors and a new section is handed over to the Client almost every 3 weeks. Therefore I’ve been heavily involved with managing the installation and the MEP handover for Section 2&3.

BM have handed over Sections 1-3 and are currently working on Section 4 but the Client has failed to accept any of Sections and it places the liquidated and ascertained damages for the 3 Sections at circa £105k per day. The main issue is the façade and the Client is refusing to inspect the outer façade because they believe it to be dirty and then they have refused to inspect the inside façade because of the outer. Still to be resolved.

View from Level 25

The 5 storey penthouse is still for sale…

Regards

Alex

Trouble at Mill

So it has been a while since I have contributed anything.  I have been placed I charge of the bulk excavation and installation of rock anchors.  Brisbane Casino Towers is now down to Bulk Excavation Level across half of the site and I am supervising the detailed excavation before handing over to the Structural Site ‘engineer’ (the lack of capitals is deliberate).  The last 2 months have been somewhat of a rollercoaster and I have learned a great deal from the experience.  With the approach of AER 2 it is a good point to review some of the issues that I have had overcome.

Loading Platform

 In order to assist with the extraction of soil from the site a loading platform was designed to carry a 47 Tonne excavator.  The loading platform was situated on the Hope Street side of the excavation.  On 14 April 2016, the braces on the loading platform buckled, halting all loading out of soil and stopping all construction materials from being loaded in.  There was a two day delay while engineers could assess the problem and carry out repair work. 

The braces buckled due to movement in the secant pile wall that induced a load that exceeded the capacity of the I wrote a TMR on the buckled braces and the stability of the platform down to foundation level.  It turns out that at full excavation the wall movement could cause failure and I recommended some alternate tension only restraints back to the secant pile wall as well as a brace back to the loading platform deck to limit the effective length.  We held a conference with the designers who were reluctant to admit any wrong doing and just wanted to replace the braces like for like.  My PM’s decsion was that we had the sign off from  a qualified engineer so it wasnt a problem!

Thankfully the 47 T excavator has now gone and a long reach (33T) has replaced it.  The sub-contractor has decide not to risk it (I may have had a word in his ear) so is leaving the excavation high underneath the platform until the platform is removed which has therefore limited the deflection of the retaining wall and the effective length of the plunge columns.

Wallap Analysis.  Caution should be used in future projects in the extent to which Wallap analysis can be relied upon for predicting deformations.  A safe approach to take is to assume that a wall will deform and design accordingly.  Future deformations should be quoted within a range (for example 25-50 mm) to give the appropriate level of understanding to those unfamiliar with geotechnical analysis.  

Safety.  The Australian approach to safety is similar to the UK’s but different.  The Union are seen as the gatekeepers of safety and not the government.  Occupational Health and Safety are Australia’s version of version of HSE but they don’t have anything like the powers.  Instead Union delegates hold builders to ransom over safety and the approach can seem sporadic at best.  BM have a minimal approach to PPE and it is not unusual to see guys laying concrete in board shorts.

 If provoked will strike!

Industrial Relations.  Seemingly minor issues are over inflated to put pressure on the state and national governments or employers.  The Union effects almost everything in the construction industry and sub-contractors can be blackballed and banned from site even if they have gone through a comprehensive tender process.  Walk-outs are common and safety/welfare incidents can be orchestrated to give the pretence for a walk out.  To make matters worse if workers down tool for safety reasons they are entitled to a full day’s pay and can even be paid to leave site for a 2hr meeting/march.  My site is only around the corner from the Union Headquarters so workers are typically called in for rent a mob demonstrations.   It is so bad that you cannot even use the word ‘union’ in correspondence.  I had a walk out on site relating to cracks in the secant pile wall when I was drilling the first row of ground anchors.  Despite displaying the monitoring results and analysis of the wall the Union delegate held the company over a barrel making various demands before allowing the boys back to work.  As a consequence our survey budget has been blown out of the water monitoring wall deflections daily.  The only consolation I have is that as bad as they are here they are even worse in Melbourne – you have my sympathy Jo.

First footing in and boom the steel budget gone

Budget.  Money is really to tight to mention on this job.  BM bought the work from the client in the hope of becoming the preferred contractor.  As such we are trying to cut costs all over the place. The decision has been made not to pour blinder and we are laying the footing straight onto the phyllite rock.  Incredibly BM have run out of money for steel after our first footing.  At tender the consulting engineer estimated 50 Kg/m³ as opposed to the 80-100 Kg/m³.  We have blown that in the first mammoth pad footing.  Another Brisbane Casino Towers budgeting classic.  We are debating the merits of back charging the consultant as we speak.

Pile Tolerance.   The secant pile wall is the permanent solution for the retaining wall.  At a depth 18 m the worst offending piles are off by approximately 200 mm and need to be ‘scabbled’ back in order to fit the ground anchor walers on.  This causes an issue as the cover is supposed to be only 150 mm, so far we have not hit steel and I am beginning to wonder if they are reinforced!  The piling contractor (Franki) actually haven’t done a bad job as out of the 264 piles on the job only 8 are problem children.  I have been told by the Franki that you would be unlikely to see this type of wall beyond 6 m in depth in Europe.

Programme.  We are currently 10 days behind programme and Delta are due to pay $15,000 a day for every day they delay the basement handover.  So this could be quite expensive for them.  BM are less interested in pursuing the Liquidated Damages (LD) are more interested in getting the time back as BM’s LDs to the client for delayed completion are nearly 3 times that.  So why did these companies agree to the LDs, well they are part of how business gets done down under and are routinely incorporated into every contract.  Normally the LDs are not pursued because there is a small construction community but given the tight budget that BM are operating under they have very little choice.

I have probably written enough for one post but I will follow up with another article on rock anchors and engineering in rock.

Rich/Dam0

PSB

Calcs are indicative only!!  (The brace is 6 m long)