Recently, Patuca III Hydropower Project in Honduras has made great advance: upstream cofferdam and plant cofferdam completed pouring, No. 1 diversion tunnel completed and No. 2 began to construct, dam abutment grouting gallery at right bank finished excavation work and many critical project node targets had been realized.
Patuca III Hydropower Project is located at downstream 5 km on Patura River, Honduras, Central America and 50 km from capital of the largest province, Olancho. Annual average flow in dam region is 134 m³/s, and after completion, it can generate electricity 104 MW.
This hydro-junction consists of RCC gravity dam, flood discharge system and diversion and power generation system. Maximum height of dam is 57 m and length is 207.1 m, crest elevation is 294 m. There are 5 holes for flood discharge and each hole is 14 m wide and 21 m high. Designed flood discharging capacity is 13700 m³/s.
During diversion system of Patuca III Hydropower Project, No. 1 and No. 2 diversion tunnel are 174 m and 202 m long, diameter are 8.6 m to 9 m. Geological condition of tunnel is mainly IV and V class surrounding rock, with excavating and supporting at the same time.
80 m grouting gallery excavation and support work was completely finished on July 20. During excavation, project constantly overcame disadvantage geological conditions of fault fracture zone and weathered rock formation, adopted shotcrete rockbolt mesh and steel grit method to deal with and then ensured grouting gallery’s construction safety, quality and schedule.
Rock bolt combines drilling, grouting and anchoring together, ensuring surrounding rocks’ pouring and tunnel excavation smoothly. Its high efficiency and convenience are benefit for flood prevention and safe construction work in rainy season and ensure normal advance of critical path. So, rock bolt has great significance for the whole project.