Astaldi of Italy and ICE of Bolivia using Robbins TBM in hard, faulted, abrasive sandstone of 40-125 MPA. March 1999.
A state of emergency was declared in Bolivia following protests about the expected rise in water charges that will accompany the $200 million Misicuni waterworks contract in Cochabamba. The centrepiece of the project is a very difficult 19 km-long diversion tunnel, which was commenced in 1995. TBM operations in the Calio sector got underway in November, 1998 and less than 500 m has been accomplished to date due to cataclastic rocks associated with a 700 m-wide fault system under 800 m cover. The plasticity of the strata causes a squeezing of 10-12 cm immediately behind the TBM which, if not supported before the crown opens, results in cave-in. Advance in April at Calio was 85 m, the highest achieved to date and in the Bocatoma sector the Robbins TBM has completed 2.5 km. Type in Misicuni at www.alltheweb.com for further details. May 2000.
Contract extension granted to Astaldi to complete excavation until 30th April, 2002 of the 19.5 km Misicuni water tunnel in Cochabamba and install the lining by 11th March, 2003. Contractor ICE withdrew from the contract. Early September, 2001, 8.4 km had been bored between the intermediate shaft and the Bocatoma portal, as well as 6.1 km between the intermediate shaft and Ventana Calio with 4 km still to go on the latter section. Bolivia's government accepted in September, 2001 a proposal by US consultant Glenn Genkins to separate the US$62 million construction of the Misicuni tunnel from other assignments. 46/01.
Supreme Decree issued by the government of Bolivia on 25th February, 2002 allowing Empresa Misicuni to negotiate a contract with another contractor to finish the last 500 m of the 19.3 km-long Misicuni tunnel. Contract with Astaldi-ICE jv was cancelled after the jv stopped work in January. The project, first proposed nearly 50 years ago, has been underway since 1995 after extensive engineering studies by Electrowatt Engineering in the 1980s. Tunnelling started in 1998 and the Bocatoma section of the tunnel was completed in May, 2000 when the Robbins hard rock TBM reached the intermediate shaft. This shaft, at over 3,800 m elevation, is one of the highest in the world. The Robbins TBM at Calio achieved advances exceeding 840 m/month, 240 m/week, 55 m/day and 30 m/shift. Antony Ivan Smith is presently the Superintendente of the 12 km-long Calio section of the Misicuni tunnel. More from aivansmith@msn.com. 12/02.
Empresa Misicuni signed on 19th March a contract with Robbins to complete the last 500 metres for $680,000 saying Robbins has the know-how to finish the tunnel under the same terms as the Astaldi-ICE jv, which pulled out from the project. Robbins equipment was used by the jv. Tunnelling is to resume by the end of March. Time frame of 45 days. Court arbitration will be given in Paris to sort out the dispute between the jv and Empresa Misicuni. Visit www.robbinstbm.com 13/02.The 19.2 km-long Misicuni tunnel was completed on Thursday 4th July, 2002 when the Robbins TBM 1015-271 finally bored into the Pozo section of the tunnel, which had been found flooded at original breakthrough on 15th June, 2002. Water is now flowing through the 5 km-high Cordilleran Andes to the Cochabamba Valley, realizing a 45 year dream. After the removal of the TBM, the Calio section of the tunnel will be concreted. For further information contact Antony Ivan Smith aivansmith@msn.com or visit www.robbinstbm.com 29/02.