Esti Hydropower Plant

Project Information: Conveyance tunnel of 4,500 m in length. Demolished due to building defects and land swelling. Work consists of the design and build of definitive repairs, covering, plating and new access points to the tunnel to allow the Esti plant to start operations. No swelling has been detected – seems to be due to red agglomerate washout aggravated by dewatering. These are emergency works. 80,000 m3 of concrete. 500 HEB 160 trusses. 84,300 Kg consolidation injections. 14,000 m3 demolition excavation. 7,120 units of 4 m MN16 swellex bolts.

Country: Panamá

Province: Chiriquí

Place: David


  • Simple tunnel of 9 m diameter and 4.5 km in length + 2 50 m² ADIT

Overburden: 400 m

Method of Tunneling:

  • Drill and blast. Execution of support repairs. Cement covering with steel fibres.

Geology and Geotechnical Data:

  • Volcanic sandstone. Tuffs and conglomerates with montmorillonite inserts.

Tunnel Equipment:

  • Atlas Copco Jumbos XL2C
  • Robots PM500
  • CAT 320 backhoes
  • Manitou platforms