Gas Turbine Base Failure 1

[msamuels]

In the pictures attached, I have concluded that this failure is a tensile uplift due to the dynamic loading. The foundation system is a pile supported pier. It cracks along the top edge perimeter including vertically at the vertical edges/corners. Your comments on the failure as well as a recommended fix.

 

[civilperson]

I suggest a post tensioned foundation with well developed anchor rods.

 

[msamuels]

We were contemplating grouting with conbextra EP10 as a temporary fix. Whats your opinion of the failure. The maximum vibrations were 12 mm/sec with an allowable of 25. The crack seem to go 3 inches beyound the rebar cage on the pier. We only have 18 days to repair, your method would seem to require a lot of downtime

 

[boo1]

Where is the generator located ST. ANDREW -- Rockfort?

 

[msamuels]

No, St James

 

[SlideRuleEra]

Whats your opinion of the failure.

Insufficient development of anchor bolts in the foundation.
Opinion for Temporary Fix: Per your plan, and make sure machine vibration is minimal.
Opinion for Permanent Fix: Longer anchor bolts with replacement foundation that has increased thickness (if necessary for the longer bolts).

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[msamuels]

I just finished reviewing the article "from experience Alternatives to ACI 318-02 July 2004" and it actually speaks to the exact same thing. The problem is how to go about doing this with considerable demolition & downtime. Considering Steel Dowells with a nut at the end in a high strenght & bonding grout, however these dowells would have to be placed in such a way to transmit dynamic shear stresses to vertical bars in the pier then to the piles. Location would definately be a problem. Your suggestions on the repair methodology.

 

[ishvaaag]

For vinculation of the whole mass till piles vertical drills ending in some bell shaped anchor within the pier (some deployable bit may be needed). If not wider rotary pipe size drills then roughened and reinforced, maybe nut at bottom. Reinforcement somewhat prestressed to grip movement, maybe spring or damping nut from above, clamped.

If you presume interface piles-pier damaged the same on piles longer, thicker.

Grout everything.

 

[msamuels]

Analysing the failure which theoretically could derive from: Insufficient development of anchor bolts, as well as insufficient steel detailing to transmitt load or capacity of steel reinforcement design, these are all design shortcomings. The question now is; how liable is the principal engineering firm, considering that the plant was commissioned in 2002

 

[boo1]

Have you done a vibration analysis of your turbine (Bogue GT)?

Do you have the Manning Industries, Inc. as built drawings?

 

[msamuels]

The unit turbine as well as generator has continuous vibration indicators installed. Despite the turbine never exceeding allowable, if there was vibration on the turbine due to a gearbox between the turbine and the generator shafts these vibrations would not be transfered either way, thus eliminating the turbine. Generator vibration was minimal (0.9 mm/sec) even with the crack.