Geotechnical & Tunnel Consultants

A consultant is a universal observer who can look at a problem outside the environment in which the problem came to be, thereby creating a solution that was never possible before.  Fernando Flores

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B-Type 1 or 2?
C-Jacked Pipe Failure
D-Top of Rock
E-PI Litigation Support
F-Geotech Assessment
G-Microtunneling Hard/Soft
H-Machine Failure
I-Boulders-Tunnel Boring
K-Plowing Utilities
L-Rock Socket Overrun
M-Bored Tunnel Inflow
N-Rock Comminution
O-Sub-Std TBM Performance
P-Bored Tunnel-Shear Zone
Q-Disputes Resolution
R-Problem Proj. Completion
S-Bored Tunnel Overbreak
T-Auger Sampling Problems
U-Bored Tunnel Delay
V-Hoe Ram - Failure to Rely
Peter J. Tarkoy
machine, performance, failure, microtunneling, stalled, cutterhead, Tarkoy, GeoConSol

Machine Failure to Perform 
---on behalf of contractor---

TBM Manufacturer provided a microtunneling machine (with detailed specifications) to excavate silt, sand, gravel, cobbles, boulders as per anticipated geotechnical conditions; 

Frank Coluccio Construction Co. retained us to investigate.  Problems manifested, were as follows:

The (rock type) cutterhead supplied for mining the silt, sand, gravel, cobbles, and occasional boulders actually mined upward into material above the tunnel that contained a larger fraction of boulders .....................................

and collapsed the pavement and stalled without advancing.

The cutterhead was replaced, yet the machine kept stalling. 

It was discovered that the machine could not deliver manufacturer specified forces at the cutterhead, stalled on a number of occasions collapsing the pavement and/or necessitating dig up.

The source of the problem was mismatching of components (cables, VFD, etc.)  and TBM manufacturer's absolute refusal to acknowledge them.


Contractor tunneling problem bankrupts Herrenknecht.

Publication: Underground Construction
Date: March 2001

A Seattle contractor that had cutterhead, torque and electrical problems with a new model of German microtunnel boring machine has won a $5.8 million arbitration award against Herrenknecht Corp. for the defects. However, on the day before the award was to be made final, the Auburn, Washington-based subsidiary of Germany 's Herrenknecht AG filed for Chapter 11 protection in federal bankruptcy court.

 Frank Coluccio Construction Co. agreed to lease-purchase a $2 million Herrenknecht AVN 1600E microtunnel boring machine with a new type of electric drive in May 1997. It was used on a 500-foot-long, 84-inch diameter utility crossing of the Duwamish River in King County , WA , and for a 5,000-foot-long, 78-inch diameter tunnel in Pierce County . According to Coluccio, the machine had a warped jacking frame, which caused the jacks to bind during retraction. A drive motor failed as did a hydraulic heat exchanger. In April 1999, the contract was terminated.

  Herrenknecht started the arbitration under the lease-purchase agreement. Last Nov. 11, arbitrator Greg Harris, a Seattle attorney, found partially in favor of Herrenknecht. He awarded the firm $430,571 for parts and services. Harris also awarded the contractor $32,526 in damages for the Duwamish project and $5 million for the Pierce County project. Harris said Herrenknecht did not have an obligation to repurchase the machine, but had to pay $300,000 to repair defects. Those largely had to do with the electrical configuration which reduced torque.