Briefing of Xiaolangdi Project
The Xiaolangdi Multipurpose Dam Project (hereinafter referred as XLDP）
is located in the exit of the last gorge in the middle reach of the Yellow River, about 40
km north of Luoyang City, 130 km downstream of Sanmenxia Dam, and 128 km upstream of
Huayuankou in Zhengzhou City. It will be the only reservoir with a large storage capacity
on the main stem of the Yellow River downstream of Sanmenxia.
The catchment area upstream of the dam site covers 694 thousand km2, accounting for 92.3% of the Yellow River basin. The total storage capacity of the reservoir is 12.65 billion m3, including 5.1 billion m3 long-term effective storage capacity.
XLDP consists of a dam, flood discharging structures and power facilities. The earth and rockfill dam has a sloping clay core, with the crest length of 1667 m, and a maximum height of 154 m. The flood discharging structures are composed of intake towers, three orifice tunnels, three free flow tunnels, three sediment release tunnels, one service spillway and plunge pools. The power facilities include six power tunnels, one underground powerhouse (6?00 MW turbines), three tailrace tunnels and one switchyard.
The main objectives of XLDP are flood control, sediment control as well as water supply, irrigation and power generation. Upon completion of XLDP, significant comprehensive benefits will be achieved, i.e. the flood control level along the middle reach of the Yellow River will be raised from the current level of less than one in sixty years to that of one in 1000 years; the lower reach of the Yellow River, with the co-operation of Sanmenxia Reservior, will basically be relieved from danger caused by ice jam; 7.5 billion m3 of silt will be deposited in the reservoir, thus decelerating the sedimentation at the lower reach of Yellow River thereby the river bed downstream will not be raised in the following twenty years, consequently avoiding the cost otherwise for 2-3dyke raising campaigns; an additional quantity of 2 billion m3/year of water will be provided to considerably better the conditions for farmland irrigation and municipal water supply at the lower reaches of the Yellow River; the power station will generate electricity of annual average 5.1 GWh on long term basis, and will be an ideal plant in the Hennan Power Grid for peak load adjustment.
Features of Xiaolangdi Multipurpose Dam Project |
||
Name of project |
Xiaolangdi Multipurpose Dam Project |
|
Construction location |
Border of Mengjin County and Jiyuan City, Henan Province |
|
River |
Yellow River main stream |
|
Rock at the Dam |
2 and 3 iteration sandstone, siltstone and claystone |
|
seismological intensity at dam area |
7 on the Richter scale |
|
| Features of Reservoir |
Performance of adjustment |
non-complete adjustment |
Designed flood level(0.1%) |
274m |
|
Check flood level(0.01) |
275m |
|
Normal high water level |
275m |
|
Normal dead water level |
230m |
|
Reservoir area at normal water level |
272.3km2 |
|
Back water length at normal water level |
128.0km |
|
Total capacity of the lake |
12.65 billionm3 |
|
Capacity for flood control |
4.05 billionm3 |
|
Capacity for sand and water adjustment |
1.05 billion m3 |
|
Capacity for sediment |
7.55 billion m3 |
|
inundated arable land |
0.185 million mu |
|
relocated population |
0.188 million |
|
| Discharge flow |
Maximum discharge flow at normal water level |
17327m3/s |
Maximum discharge at designed water level |
13480m3/s |
|
Maximum discharge flow at check flood level |
13990m3/s |
|
Maximum discharge flow at normal dead water level |
8048m3/s |
|
Maximum discharge flow at unusual dead water level |
6769m3/s |
|
| Main quantities of work |
Soil and rock open excavation |
36.25 million m3 |
Rock tunnel excavation |
2.8 million m3 |
|
Soil and rock fill |
55.74 million m3 |
|
Concrete and concrete reinforcement |
3.37 million m3 |
|
Metal structure installation |
0.0326 million t |
|
Installation of mechanical and electrical equipment |
0.0309 million t |
|
Curtain (consolidation) grouting |
0.212(0.347 million m) |
|
Backfill(joint) grouting |
0.2474 million m2 |
|
| Comprehensive efficiency |
(1) Flood control |
Flood control capacity in the lower reach is raised from every 60 year flood to every 1000 year flood. |
(2) Ice jam control |
Ice jam damage can basically be avoided. |
|
(3) Sediment reduction |
Dike raising in the lower reach is reduced 2-3 times. |
|
(4) Water supply |
Increased average adjustment water quantity is 2 billion m3. |
|
(5) Irrigation |
Increased irrigation area is 40 million mu. |
|
(6) Power generation |
Yearly average power generation is 4.599 kWh/ 5.851 kWh (the first 10 years/ 10 years after). |
|
Commencement date of the first period work |
1-Sep-91 |
|
Commencement date of the main work |
12-Sep-94 |
|
Completion date |
31-Dec-01 |
|
Employer |
Construction and Management Bureau of Xiaolangdi Multipurpose Dam Project, MWR (Yellow River Water and Hydropower Development Corporation) |
|
Supervisor |
Xiaolangdi Engineering Consulting Corporation Ltd. |
|
Designer |
Yellow River Commission reconnaissance , Planning and Design Institute |
|
| Contractor |
Lot 1 (main dam) |
Yellow River Contractor sponsored by Italian Impregilo Company, China Water Resources and Hydropower Engineering Bureau No. 14 as partner |
Lot 2 (Intake, Tunnel and Spillway) |
Chinese-German-Italian Contractors sponsored by German Zublin Company, China Water Resources and Hydropower Engineering Bureau No. 7 and 11 as partners, Bureau Nos. 1, 3, 4, 7 and 14 as subcontractors |
|
Lot 3 ( Power Facilities) |
Xiaolangdi Joint Venture sponsored by French Dumez Company, China Water Resources and Hydropower Engineering Bureau No. 6 as partner |
|
Local Contractor |
Water Resources and Hydropower Engineering Bureaus directly under MWR, Yellow River Engineering Bureau, Shaanxi Engineering Bureau |
|
Features of Structures of Xiaolangdi Multipurpose Dam Project |
||
| Dam |
Type |
Rockfill dam with inclined clay core |
Dam crest elevation, designed maximum height |
281m, 154m |
|
Volume |
51.85million m3 |
|
Crest length, width |
1667m, 15m |
|
Maximum bottom width |
864.0m |
|
Foundation seepage control |
Concrete cut-off wall (thickness:1.2m, depth:80m) |
|
| Intake Tower |
Type |
Deep intake in tower form |
Layout |
Concentration layout of towers like Chinese character " 一" |
|
Dimensions of towers(width x length x height) |
276.4m x (52.8-70.0)x 113.0m |
|
| Diversion tunnels |
Number |
3 |
Section dimensions |
D14.5m |
|
Length (1#, 2#, 3#) |
1120m, 1183m, 1149m |
|
Intake invert elevation (1#, 2#, 3#) |
132m, 141.5m, 141.5m |
|
Type of plugging gate, gate hole dimensions |
Sliding plain gate, 12 x 14.5m |
|
Maximum discharge(1#, 2#, 3#) |
2960m3/s, 3250m3/s, 3250m3/s |
|
| Orifice discharge tunnel |
Type |
Muti-cascade energy dissipation |
Number |
3 |
|
Section dimensions |
D14.5m |
|
Length (1#, 2#, 3#) |
1134m, 1121m, 1121m |
|
Intake invert elevation (1#, 2#, 3#) |
175m |
|
Type of working gate |
Off centered hinge joint arc gate |
|
Gate hole dimensions (width x height) |
2-4.8 x 5.4m, 2-4.8 x 4.8m, 2-4.8 x 4.8m |
|
Maximum water head |
139.80m, 130.30m, 130.30m |
|
Maximum discharge(1#, 2#, 3#) |
1727m3/s, 1549m3/s, 1549m3/s |
|
| Sediment tunnel |
Type |
Post tension prestressed concrete lining pressure gate |
Number |
3 |
|
Section dimensions |
D6.5m |
|
Length (1#, 2#, 3#) |
1105m, 1105m, 1105m |
|
Intake invert elevation (1#, 2#, 3#) |
175m |
|
Type of working gate |
Off centered hinge joint arc gate |
|
Gate hole dimensions (width x height) |
3-4.4 x 4.5m |
|
Maximum water head |
122.3m |
|
Maximum discharge per tunnel(discharge control) |
675m3/s (500m3/s) |
|
| Free flow tunnel |
Number |
3 |
Section dimensions (width x height) 1#, 2#, 3# |
10.5 x13m, 10 x 12m, 10 x 11.5m |
|
Length |
1093m, 1079m, 1077m |
|
Intake invert elevation (1#, 2#, 3#) |
195m, 209m, 225m |
|
Type of working gate |
Cylinder hinge joint arc gate |
|
Gate hole dimensions (width x height) |
8 x 10m, 8 x 9m, 8 x 9m |
|
Maximum water head |
80m, 66m, 50m |
|
Maximum discharge |
2680 m3/s, 1973m3/s, 1796m3/s |
|
| Plunge Pool |
Type |
Concrete reinforcement multi-grade plunge pool |
Plunge pool (length, width, depth) |
165m x 356m x28m |
|
Stilling Basin (length, width, depth) |
45m x 352m x 15m |
|
Apron (length, width, depth) |
82m x 360m x 10m |
|
| Power tunnel |
Type |
pressure tunnel/penstock (before curtain/ after curtain) |
Number |
6 |
|
Section dimensions |
D7.8m |
|
Length (1#, 2#, 3#, 4#, 5#, 6#) |
423.79m, 408.01m, 386.37m, 369.41m, 340.24m, 324.27m |
|
Intake invert elevation (1#, 2#, 3#) |
1~4#-195m, 5~6#-190m |
|
Type of emergency working gate |
Fixed wheel flat gate |
|
Gate hole dimensions (width x height) |
6-5 x 9m |
|
Diversion flow |
6 x 296m3/s |
|
| Power House |
Type |
Underground power house |
Dimensions (length, width, height) |
251.5 x 26.2 x 61.44m |
|
Capacity |
6 units, 300mw per unit |
|
Guaranteed output |
283.9/353.8mw (the first 10 years/ 10 years after) |
|
Hours of annual use |
2560/3250 hours ( the first 10 years/ 10 years after) |
|
Maximum water head |
128.92m/138.92m (the first 10 years/ 10 years after) |
|
Minimum water head |
65.79m/90.79m (the first 10 years/10 years after) |
|
Designed water head |
112m |
|
Type of turbine |
Vertical shaft combined flow turbine |
|
Installation elevation |
129m |
|
Main transformer |
6 sets, 360MVA/500KV; 2 sets, 540MVA |
|