Jinping II Hydropower Station is an important cascade power station on the Yalong River with the total installed capacity of 4,800MW and single capacity of 600MW. The project hub was mainly composed of three parts: the first sluice, the water diversion system and the underground workshop at the tail. It was a low sluice, a long tunnel and a large capacity diversion power station. The buried depth of the overlying rock mass along the diversion tunnel group was generally 1,500-2,000m, and the maximum buried depth is about 2,525m. The grouting process of #3 and #4 diversion tunnel started on August 18, 2007 and was completed on September 30, 2014.
This project was characterized by the deep burial, long line and large diameter. Multi-arm drilling was adopted, and the section flow line operation of the grouting platform was used to complete the backfilling grouting of #3 hole 154,277.04m, consolidation grouting 464,302.49m, open rock grouting 32,248.60m, and water plugging grouting 66,588.50m respectively. The backfilling grouting of #4 hole was 158,193.38m, the consolidation grouting was 424,134.94m, the open rock grouting was 22,568.00m, and the water plugging grouting was 46,823.37m.
The construction technology of large water point plugging was adopted, as well as the rapid drilling
technology of Atlas hydraulic drilling machine. In the process of grouting construction, a record of
the highest completion of 78,000 meters in a single month was created, and water plugging grouting
completed the blocking of 3.6m3/s of single point water output.
The project has won the
"2018-2019 National Gold Award for Quality Engineering", "16th China Civil Engineering Zhan
Tianyou Award", "2018 National Science and Technology Progress Second Prize" and "Fedic Engineering
Project Outstanding Achievement Award".
Located in the lower reaches of the Yalong River, The Guandi Hydroelectric Dam is the third cascade hydropower station that was planned to be developed in the fifth stage of the Yalong River between Kala and Jiangkou, with an installed capacity of 2400MW and total storage capacity of 760 million cubic meters. The dam is a RCC (roller-compacted concrete) gravity dam with a maximum height of 168m. The dam curtain grouting layout had two layers of grouting holes, extending to the two sides of the dam to the deep mountain, and to the dam foundation and dam foundation grouting corridor curtain as a whole, forming the dam's overall cut-off barrier. The construction began in October 2009 and was completed in October 2011.
The cut-off curtains were arranged along the grouting gallery of the dam foundation, the grouting holes and the stilling ponds of each layer of the dam abutment. The curtain grouting line was long, the working face was scattered, and the construction intensity was large. The small-diameter orifice-closed inner circulation method was adopted for construction, with the deepest hole of curtain reaching more than 120m, and the total engineering amount being about 150,000m. Both sides of the dam shoulder hole were more than 120-meter-deep, and the use of non-core drilling greatly improved the drilling efficiency and construction quality. The project adopted geomantic linkage hole washing method to effectively solve the drilling hole washing problem of gouge fault. This project has won the "2018 China Electric Power Quality Engineering Award".
Dagang Muntain Hydropower Station is located in Dujiao Township, Shimian County, Sichuan Province. It is the 14th cascade power station planned for the Dadu River trunk stream. It has a 210m high concrete double-curved arch dam with the world's highest seismic fortification standard, a total storage capacity of 742 million cubic meters, and a total installed capacity of 2,600 MW(4×650MW). The hub of the power station was mainly composed of concrete hyperbolic arch dam, flood discharge and energy dissipation buildings, water diversion and power generation buildings, etc. The construction began on March 15, 2011 and was completed on August 31, 2016.
The anti-seepage curtain was composed of three parts: the dam foundation curtain, the left bank powerhouse curtain and the second dam curtain. Among them, the dam foundation curtain was connected with the left bank powerhouse curtain to form an anti-seepage system in the reservoir area. The small-diameter orifice-closed hole internal circulation method was adopted for construction, and the maximum curtain hole depth was 158m. A total of 400,000m curtain drilling grouting, 2100m chemical grouting and 58,000m drainage holes were completed. The use of ultra-deep hole curtain grouting hole inclination control technology, deep hole curtain grouting re-grouting and thickening construction technology, and V-type diabase vein composite grouting construction technology.
The project won the "2018-2019 National Quality Project Gold Award", "2018 National Science and Technology Progress Award Second Prize", "17th China Civil Engineering Zhan Tianyou Award", "2018 China Electric Power Quality Project", "2018 Excellent Construction Project" First Prize of Design Achievement" "2016 First Prize of Science and Technology Innovation Achievement Award of China Implementation Enterprise Association" and "3rd Prize of 2018 China Electric Power Technology Progress Award".
The Lianghekou Hydroelectric Dam is located on the main river of The Yalong River in Yajiang County, Ganzi Prefecture, Sichuan Province. It is the leading power plant in the middle and lower reaches of the Yalong River, with a total storage capacity of 10.67 billion cubic meters and an installed capacity of 3,000 MW. The main buildings of the hub include gravel-soil straight-core wall rockfill dams, tunnel spillways, deep-hole spillway tunnels, shaft spillway tunnels, emptying tunnels, and water diversion and power generation systems. The maximum dam height of the gravel-soil straight-core wall rockfill dam is 295m. The construction started on June 6, 2016 and is currently under construction.
The dam foundation consolidation grouting was arranged within the range of the core wall foundation of the gravel-soil core wall of the rockfill dam. The designed consolidation grouting was 108,000m, and the 100B down-the-hole drilling machine was used for construction. The pivotal cut-off curtain was composed of the dam cut-off curtain and the underground powerhouse cut-off curtain.
The designed curtain grouting was 578,000m, and the small-diameter orifice-closed hole internal circulation method was adopted. The maximum hole depth of the main curtain grouting was 155m. The qualified standard was that the water permeability is not lager than 1Lu. The project adopted deep-hole curtain grouting liquid reflux construction technology, deep-hole curtain fissure pressure-bearing water grouting construction technology, and overhanging curtain upper hole sealing construction technology. The project also used grouting construction lifting prevention and control technology under high and steep slope conditions, and curtain cement-chemical grouting construction technology in the triangle area of bank slope under high and steep slope conditions.
