This standard applies to newly built water conservancy and hydropower projects such as flood control, irrigation, power generation, water supply and waterlogging control. SL 252-2000 Water conservancy and hydropower project classification and flood standards SL252-2000 standard download decompression password: www.bzxz.net

SL252-2000 Standard for Classification and Flood Control of Water Resources and Hydroelectric Project 2004-125 Issued on 2000-07-13 Ministry of Water Resources of the People's Republic of China Implemented on 2000-08-01 Industry Standard of the People's Republic of China Standard for Classification and Flood Control of Water Resources and Hydroelectric Project ProjectSL252—2000
Main Editor: Yangtze River Water Resources Commission Yangtze River Survey, Planning and Design Institute Approval Department: Ministry of Water Resources of the People's Republic of China Effective Date: August 1, 2000
China Water Resources and Hydropower Press
2000Beijing
Ministry of Water Resources of the People's Republic of China
Notice on Approval of Issuance of "Classification of Water Conservancy and Hydropower Projects and Flood Standards" SL252-2000 Shuiguoke [2000]] No. 283
To all relevant units:
According to the Ministry's water conservancy and hydropower technical standards formulation and revision plan, the "Classification of Water Conservancy and Hydropower Projects and Flood Standards" revised by the Yangtze River Water Conservancy and Hydropower Planning and Design Institute, with Yangtze River Water Conservancy Commission Yangtze River Survey, Planning and Design Institute of the Ministry of Water Resources as the main editor, has been reviewed and approved as a water conservancy industry standard and has been issued. The name and number of the standard are: "Classification of Water Conservancy and Hydropower Projects and Flood Standards" SL252-2000. After implementation, this standard will replace SDJ1278 "Classification and Design Standards for Water Conservancy and Hydropower Projects (Mountainous and Hilly Areas) (Trial)", SDJ12-78 (B) "Supplementary Provisions for Classification and Design Standards for Water Conservancy and Hydropower Projects (Mountainous and Hilly Areas) (Trial)" and SDJ217-87 "Classification and Design Standards for Water Conservancy and Hydropower Projects (Plain and Coastal Areas) (Trial)". This standard shall be implemented from August 1, 2000. During the implementation process, please pay attention to summarizing experience. If there are any questions, please inform the host department in writing, and it will be responsible for interpretation. The standard text is published and distributed by China Water Conservancy and Hydropower Press. July 13, 2000
According to the technical standard formulation (revision) plan issued by the Ministry of Water Resources in 1997, the Yangtze River Survey, Planning and Design Institute revised SDJ12--78 "Classification and Design Standards for Water Conservancy and Hydropower Projects (Mountainous and Hilly Areas)" (Trial) and SDJ217-87 "Classification and Design Standards for Water Conservancy and Hydropower Projects (Plain and Coastal Areas)" (Trial). The revised standard combines the contents of the above two standards and makes necessary supplements and modifications, and is named "Classification and Flood Standards for Water Conservancy and Hydropower Projects". This standard mainly includes the following contents:
1. Provisions for the classification of water conservancy and hydropower projects; 2. Provisions for determining the grades of hydraulic structures of water conservancy and hydropower projects; 3. Provisions for determining flood standards and safety overheights for hydraulic structures of different regions and different water conservancy and hydropower projects.
The supplements and revisions to SDJ12-78 and SDJ217-87 mainly include the following aspects:
1. Adding the provisions on the grades of sluice projects and pump station projects; 2. Adding the provisions on the grades, flood standards and safety heightening of embankment projects; 3. Adding the provisions on flood standards for irrigation, waterlogging control, water supply and other engineering buildings; 4. Modifying the original provisions on the grades and flood standards of temporary hydraulic structures; 5. Partially adjusting the classification indicators of water conservancy and hydropower projects and the flood standards of hydraulic structures;
6. The provisions on the safety factor of anti-sliding stability in the original standards are changed to the provisions of various special specifications. This standard is interpreted by: the Ministry of Water Resources Water Resources Planning and Design General Institute This standard is compiled by: Yangtze River Survey, Planning and Design Institute of Yangtze River Water Resources Commission This standard is mainly drafted by: Xu Linxiang Chen Jian Wang Zhongfa Wei Shanzhong Chen Suli Zhong Qi Wang Hong Huang Jianhe Wei Xinzhu Jiang Jikai Huang Qizhi Chen Chuanhui 2 Project grades and building levels 2.1 Project grades and hydraulic structure levels 3 Flood standards 3.1 General provisions Permanent water conservancy and hydropower projects in mountainous and hilly areas 3.2
3.3 Permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas 3.4 Permanent hydraulic structures of other water conservancy projects 3.5
Temporary hydraulic structures
4 Buildings that are too high
Terms used in this standard
Article explanation
1 General
1.0.1 In order to ensure the safety of life and property of people in water conservancy and hydropower projects and their downstream (or protected areas) and the normal performance of project benefits, this standard is formulated based on the level of social and economic development in my country.
1.0.2 This standard applies to newly built water conservancy and hydropower projects such as flood control, irrigation, power generation, water supply and waterlogging control.
When it is difficult to implement this standard for the reinforcement, reconstruction or expansion of existing water conservancy and hydropower projects, appropriate adjustments may be made after sufficient demonstration and approval by the competent authorities. 1.0.3 When determining the grade of water conservancy and hydropower projects, the level of buildings and flood standards, the relationship between the local and the whole, the short-term and the long-term, the upstream and the downstream, the left bank and the right bank should be reasonably handled.
1.0.4 For water conservancy and hydropower projects that are large in scale, involve a wide range of areas and are particularly important, their grades, building grades, flood standards and safety superelevations can be specially demonstrated when necessary and determined with the approval of the competent authorities.
1.0.5 In addition to complying with this standard, the grades and flood standards of other professional buildings in water conservancy and hydropower projects should also comply with the provisions of the relevant national standards in force. 1
Project Grade and Building Grade
2.1 Project Grade
The grade of water conservancy and hydropower projects should be determined according to Table 2.1.1 based on their project scale, benefits and importance in the national economy. Table 2.1.1
Large (1) type
Large (2) type
Total reservoir
(108m3)
1.0--0.10
Small (1) type
0.10--0.01
Small (2) type0.01~0.001
Grading index of water conservancy and hydropower projects
Protection of towns and
industrial and mining enterprises|| tt||Importance
Particularly important
(104 mu)
≥500
(104 mu)
≥200
500~-100200~60
30～5
60～15
1.The total storage capacity of the reservoir refers to the static storage capacity below the highest water level of the reservoir; Note
2.The flood control area and irrigation area both refer to the design area. Irrigation
(104 mu)
≥150
150～50
Importance
Specially important
(104kw)
≥120
2.1.2 For comprehensive utilization water conservancy and hydropower projects, when the grades determined by the grading indicators of each comprehensive utilization project are different, the project grade shall be determined according to the highest grade. 2.1.3 The grade of the river-blocking sluice project shall be determined according to its flow through the sluice in accordance with Table 2.1.3. Table 2.1.3 Classification index of river sluice project
Project grade
Project scale
Large (1) type
Large (2) type
Small (1) type
Small (2) type
Flow rate through the sluice
(m3/s)
≥5000
5000～1000
1000~100
100～20
2.1.4 The grade of irrigation and drainage pumping stations shall be determined according to their installed flow and installed power in accordance with Table 2.1.4. The grade of industrial and urban water supply pumping stations shall be determined according to the importance of their water supply objects in accordance with Table 2.1.1.
Table 2.1.4 Irrigation and drainage pump station classification indicators Project grade
Project scale
Large (1) type
Large (2) type
Small (1) type
Small (2) type
Classification indicators
Installed flow rate (m3/s)
≥200
200～50
10～2
Installed power (104kW)
0.1～0.01
Note 1. Installed flow rate and installed power refer to the indicators of a single station including standby units; 2. When a pump station belongs to two different grades according to the classification indicators, its grade shall be determined according to the higher grade; 3. The grade of a pump station system project composed of multiple stages or multiple pump stations can be determined according to the indicators of its system. 2.2 Levels of hydraulic structures
2.2.1 The level of permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to the grade of the project and the importance of the structure in accordance with Table 2.2.1. 2.2.2 Level 2 to 5 major permanent hydraulic structures of water conservancy and hydropower projects with huge losses or serious impacts after an accident may be upgraded by one level after demonstration and approval by the competent department; Level 1 to 4 major permanent hydraulic structures of water conservancy and hydropower projects with minor losses after an accident may be reduced by one level after demonstration and approval by the competent department. 2.2.3 Permanent hydraulic structures of reservoir dams that are rated as Level 2 or 3 according to 2.2.1 may be upgraded by one level if the dam height exceeds the index in Table 2.2.3, but the flood standard may not be increased.
2.2.4 When the engineering geological conditions of the foundation of permanent hydraulic structures are complex or new structures are adopted, the design level of 2-5 buildings can be increased by one level, but the flood standard shall not be increased.
2.2.5 The level of embankment engineering shall be determined in accordance with GB50286-98 "Code for Design of Embankment Engineering". The level of hydraulic structures through dikes shall be determined according to the level of the dike project where they are located and the level corresponding to the scale of the structure, whichever is higher. 2.2.6 The level of temporary water retaining and water discharge structures used during the construction period of water conservancy and hydropower projects shall be determined according to Table 2.2.6 based on the importance of the protected objects, consequences of accidents, service life and scale of temporary structures.
Table 2.2.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protected objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of accidents
Flooding important towns, industrial and mining enterprises, and transportation arteries or delaying the total construction period and the generation of the first unit (batch), causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, and t||Or affect the total construction period and the first unit (batch) of power generation and cause great economic losses
No foundation pit, but the total construction period and the first unit (batch) of power generation are not affected greatly, and the economic losses are small
Service life
(years)
Building scale
50～15
(108m3)
1.0～0.1
When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71
the level should be determined according to the highest level. However, for level 3 temporary hydraulic structures, no less than two indicators that meet the requirements of the level shall be used. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 may be raised by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas, plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, its flood standard shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, its flood standard shall be determined according to the standards of mountainous and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of each cascade water conservancy and hydropower project are determined in a cascade development mode, the river management and development and utilization planning should be combined, and the overall research and mutual coordination should be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas should be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (year) Item
Earth-rock dam
Concrete dam,
Mutual masonry dam
1000～500
Possible maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.When a pump station belongs to two different grades according to the classification index, its grade shall be determined according to the higher grade; 3. The grade of a pump station system project composed of multiple levels or multiple pump stations can be determined according to the index of its system. 2.2 Level of hydraulic structures
2.2.1 The level of permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to Table 2.2.1 based on the grade of the project in which they are located and the importance of the structure. 2.2.2 The level of major permanent hydraulic structures of levels 2 to 5 of water conservancy and hydropower projects that cause huge losses or very serious impacts after an accident can be upgraded by one level after demonstration and approval by the competent department; the level of major permanent hydraulic structures of levels 1 to 4 of water conservancy and hydropower projects that cause little losses after an accident can be reduced by one level after demonstration and approval by the competent department. 2.2.3 Reservoir dams that are classified as Class 2 or 3 permanent hydraulic structures according to 2.2.1 may be upgraded by one level if their height exceeds the index in Table 2.2.3, but the flood standard need not be raised.
2.2.4 When the engineering geological conditions of the foundation of permanent hydraulic structures are complex or new structures are adopted, the design level of 2-5 buildings can be increased by one level, but the flood standard shall not be increased.
2.2.5 The level of embankment engineering shall be determined in accordance with GB50286-98 "Code for Design of Embankment Engineering". The level of hydraulic structures through dikes shall be determined according to the level of the dike project where they are located and the level corresponding to the scale of the structure, whichever is higher. 2.2.6 The level of temporary water retaining and water discharge structures used during the construction period of water conservancy and hydropower projects shall be determined according to Table 2.2.6 based on the importance of the protected objects, consequences of accidents, service life and scale of temporary structures.
Table 2.2.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protected objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first unit (batch), causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, t||Or affect the total construction period and the first unit (batch) of power generation and cause great economic losses
No foundation pit, but the total construction period and the first unit (batch) of power generation are not affected greatly, and the economic losses are small
Service life
(years)
Building scale
50～15
(108m3)
1.0～0.1
When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71
the level should be determined according to the highest level. However, for level 3 temporary hydraulic structures, no less than two indicators that meet the requirements of the level shall be used. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 may be raised by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas, plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, its flood standard shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, its flood standard shall be determined according to the standards of mountainous and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of each cascade water conservancy and hydropower project are determined in a cascade development mode, the river management and development and utilization planning should be combined, and the overall research and mutual coordination should be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas should be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (year) Item
Earth-rock dam
Concrete dam,
Mutual masonry dam
1000～500
Possible maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.When a pump station belongs to two different grades according to the classification index, its grade shall be determined according to the higher grade; 3. The grade of a pump station system project composed of multiple levels or multiple pump stations can be determined according to the index of its system. 2.2 Level of hydraulic structures
2.2.1 The level of permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to Table 2.2.1 based on the grade of the project in which they are located and the importance of the structure. 2.2.2 The level of major permanent hydraulic structures of levels 2 to 5 of water conservancy and hydropower projects that cause huge losses or very serious impacts after an accident can be upgraded by one level after demonstration and approval by the competent department; the level of major permanent hydraulic structures of levels 1 to 4 of water conservancy and hydropower projects that cause little losses after an accident can be reduced by one level after demonstration and approval by the competent department. 2.2.3 Reservoir dams that are classified as Class 2 or 3 permanent hydraulic structures according to 2.2.1 may be upgraded by one level if their height exceeds the index in Table 2.2.3, but the flood standard need not be raised.
2.2.4 When the engineering geological conditions of the foundation of permanent hydraulic structures are complex or new structures are adopted, the design level of 2-5 buildings can be increased by one level, but the flood standard shall not be increased.
2.2.5 The level of embankment engineering shall be determined in accordance with GB50286-98 "Code for Design of Embankment Engineering". The level of hydraulic structures through dikes shall be determined according to the level of the dike project where they are located and the level corresponding to the scale of the structure, whichever is higher. 2.2.6 The level of temporary water retaining and water discharge structures used during the construction period of water conservancy and hydropower projects shall be determined according to Table 2.2.6 based on the importance of the protected objects, consequences of accidents, service life and scale of temporary structures.
Table 2.2.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protected objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first unit (batch), causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, t||Or affect the total construction period and the first unit (batch) of power generation and cause great economic losses
No foundation pit, but the total construction period and the first unit (batch) of power generation are not affected greatly, and the economic losses are small
Service life
(years)
Building scale
50～15
(108m3)
1.0～0.1
When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71
the level should be determined according to the highest level. However, for level 3 temporary hydraulic structures, no less than two indicators that meet the requirements of the level shall be used. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 may be raised by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas, plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, its flood standard shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, its flood standard shall be determined according to the standards of mountainous and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of each cascade water conservancy and hydropower project are determined in a cascade development mode, the river management and development and utilization planning should be combined, and the overall research and mutual coordination should be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas should be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (year) Item
Earth-rock dam
Concrete dam,
Mutual masonry dam
1000～500
Possible maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.1 For permanent hydraulic structures specified as Class 2 or Class 3, if the dam height exceeds the index in Table 2.2.3, its class may be raised by one class: however, the flood standard may not be raised. 2.2.4 When the engineering geological conditions of the foundation of permanent hydraulic structures are complex or new structures are adopted, the engineering grades of Class 2 to 5 buildings, permanent hydraulic structures, major structures, secondary structures, reservoir dams, and grade-raising indicators Table 2.2.31 Earth-rock dams, concrete dams, mortar-laid stone dams, earth-rock dams, concrete dams, mortar-laid stone dams Note: The grade refers to the grade determined in Table 2.2.1. The design level of the building can be raised by one level, but the flood standard shall not be raised. 2.2.5 The level of the levee project shall be determined in accordance with GB50286-98 "Code for Design of Levee Projects". The level of the hydraulic structure through the levee shall be determined according to the level of the levee project where it is located and the level corresponding to the scale of the building, whichever is higher. 2.2.6 The level of temporary water retaining and water discharge structures used during the construction period of water conservancy and hydropower projects shall be determined according to Table 2.2.6 based on the importance of the protected object, the consequences of the accident, the service life and the scale of the temporary structure.
Table 2.2.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protected objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first unit (batch), causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, t||Or affect the total construction period and the first unit (batch) of power generation and cause great economic losses
No foundation pit, but the total construction period and the first unit (batch) of power generation are not affected greatly, and the economic losses are small
Service life
(years)
Building scale
50～15
(108m3)
1.0～0.1
When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71
the level should be determined according to the highest level. However, for level 3 temporary hydraulic structures, no less than two indicators that meet the requirements of the level shall be used. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 may be raised by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas, plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, its flood standard shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, its flood standard shall be determined according to the standards of mountainous and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of each cascade water conservancy and hydropower project are determined in a cascade development mode, the river management and development and utilization planning should be combined, and the overall research and mutual coordination should be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas should be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (year) Item
Earth-rock dam
Concrete dam,
Mutual masonry dam
1000～500
Possible maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.1 For permanent hydraulic structures specified as Class 2 or Class 3, if the dam height exceeds the index in Table 2.2.3, its class may be raised by one class: however, the flood standard may not be raised. 2.2.4 When the engineering geological conditions of the foundation of permanent hydraulic structures are complex or new structures are adopted, the engineering grades of Class 2 to 5 buildings, permanent hydraulic structures, major structures, secondary structures, reservoir dams, and grade-raising indicators Table 2.2.31 Earth-rock dams, concrete dams, mortar-laid stone dams, earth-rock dams, concrete dams, mortar-laid stone dams Note: The grade refers to the grade determined in Table 2.2.1. The design level of the building can be raised by one level, but the flood standard shall not be raised. 2.2.5 The level of the levee project shall be determined in accordance with GB50286-98 "Code for Design of Levee Projects". The level of the hydraulic structure through the levee shall be determined according to the level of the levee project where it is located and the level corresponding to the scale of the building, whichever is higher. 2.2.6 The level of temporary water retaining and water discharge structures used during the construction period of water conservancy and hydropower projects shall be determined according to Table 2.2.6 based on the importance of the protected object, the consequences of the accident, the service life and the scale of the temporary structure.
Table 2.2.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protected objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first unit (batch), causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, t||Or affect the total construction period and the first unit (batch) of power generation and cause great economic losses
No foundation pit, but the total construction period and the first unit (batch) of power generation are not affected greatly, and the economic losses are small
Service life
(years)
Building scale
50～15
(108m3)
1.0～0.1
When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71
the level should be determined according to the highest level. However, for level 3 temporary hydraulic structures, no less than two indicators that meet the requirements of the level shall be used. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 may be raised by one level after technical and economic demonstration. 4bZxz.net
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas, plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, its flood standard shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, its flood standard shall be determined according to the standards of mountainous and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of each cascade water conservancy and hydropower project are determined in a cascade development mode, the river management and development and utilization planning should be combined, and the overall research and mutual coordination should be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas should be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (year) Item
Earth-rock dam
Concrete dam,
Mutual masonry dam
1000～500
Possible maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protection objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first (batch) of units, causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, or affecting The total construction period of the project and the first unit (batch) of power generation will cause great economic losses. The foundation pit is not built, but the total construction period and the first unit (batch) of power generation will not be affected greatly, and the economic losses are small. Service life (years) Building scale 50～15 (108m3) 1.0～0.1 When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71 Their level should be determined according to the highest level. However, for temporary hydraulic structures of level 3, no less than two indicators meet the requirements of the level. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 can be increased by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas and plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, the flood standards shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, the flood standards shall be determined according to the standards of mountainous areas and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of water conservancy and hydropower projects of each cascade are determined in accordance with the river management and development and utilization planning, overall research and mutual coordination shall be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas shall be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (years) Item
Earth-rock dam
Concrete dam,
Mortar masonry dam
1000～500
Probable maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.6 Temporary hydraulic structures level
Temporary hydraulic structures
Protection objects
Level 1 permanent hydraulic structures with special requirements
Level 1 and 2 permanent hydraulic structures
Level 3 and 4 permanent hydraulic structures
Consequences of failure
Flooding important towns, industrial and mining enterprises, transportation arteries or delaying the total construction period and the generation of the first (batch) of units, causing serious disasters and losses
Flooding general towns, industrial and mining enterprises, or affecting The total construction period of the project and the first unit (batch) of power generation will cause great economic losses. The foundation pit is not built, but the total construction period and the first unit (batch) of power generation will not be affected greatly, and the economic losses are small. Service life (years) Building scale 50～15 (108m3) 1.0～0.1 When temporary hydraulic structures belong to different levels according to the indicators in Table 2.2.6, 2.2.71 Their level should be determined according to the highest level. However, for temporary hydraulic structures of level 3, no less than two indicators meet the requirements of the level. 2.2.8 When temporary hydraulic structures are used to retain water for power generation and navigation, the level of temporary hydraulic structures below level 3 can be increased by one level after technical and economic demonstration. 4
3 Flood standards
3.1 General provisions
3.1.1 The flood standards for permanent hydraulic structures of water conservancy and hydropower projects shall be determined according to mountainous areas, hilly areas and plains and coastal areas respectively. 3.1.2 When the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas is less than 15m, and the maximum head difference between upstream and downstream is less than 10m, the flood standards shall be determined according to the standards of plains and coastal areas; when the water retaining height of permanent hydraulic structures of water conservancy and hydropower projects in plains and coastal areas is higher than 15m, and the maximum head difference between upstream and downstream is greater than 10m, the flood standards shall be determined according to the standards of mountainous areas and hilly areas. 3.1.3 When the design flood and verification flood standards of permanent hydraulic structures of water conservancy and hydropower projects of each cascade are determined in accordance with the river management and development and utilization planning, overall research and mutual coordination shall be carried out. 3.2 Permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas 3.2.1 The flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas shall be determined according to Table 3.2.1.
3.2.2 For earth-rock dams, if the failure will cause particularly serious disasters downstream, the first-level building Table 3.2.1 Flood standards of permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hilly areas [Recurrence period (years) Item
Earth-rock dam
Concrete dam,
Mortar masonry dam
1000～500
Probable maximum flood
(PMF) or
10000～5000
5000~2000
Hydraulic structure
Object level
500 ～100
5000~2000
2000～1000
100~～50
50～30
30～20
200010001000~300|300~200
1000~500
200~100
500~2001
The verification flood standard for buildings should be the possible maximum flood (PMF) or the 10,000-year recurrence period standard; the verification flood standard for buildings of level 2 to 4 can be increased by one level. 3.2.3 For concrete dams and mortar-masonry dams, if floods overtopping will cause extremely serious losses, the verification flood standard for Class 1 buildings may be the possible maximum flood (PMF) or the standard with a return period of 10,000 years, after special demonstration and approval by the competent authorities. 3.2.4 The flood standard for the energy dissipation and anti-scouring design of permanent discharge structures of water conservancy and hydropower projects in mountainous and hilly areas may be lower than the flood standard of the discharge structures. It shall be determined according to Table 3.2.4 based on the level of the discharge structures, and the adverse conditions that may occur when the flood standard is lower than the energy dissipation and anti-scouring design flood standard shall be considered. For floods exceeding the energy dissipation design standard, local damage to the energy dissipation and anti-scouring structures is allowed, but it must not endanger the safety of the water retaining structures and other major buildings; and it must be easy to repair and not affect the operation of the project for a long time. Table 3.2.4 Flood standards for energy dissipation and anti-scouring structures of water conservancy and hydropower projects in mountainous and hilly areas Permanent water discharge structure level
Flood recurrence period (years)
3.2.5 The flood standard for hydropower station buildings shall be determined according to the level and the provisions of Table 3.2.5. The flood standard for the water retaining part of the riverbed type hydropower station building shall be consistent with the flood standard of the main water retaining structure of the project. The flood standard for the auxiliary powerhouse, main transformer yard, switch station, and access traffic of the hydropower station building can be determined according to Table 3.2.5. 3.2.6 If the upper and lower regulating pools of a pumped storage power station have a small volume, the damage to the downstream power station building flood after the accident is not great, and it is easy to repair. The flood standard of its hydraulic structures can be determined according to its level and the regulations of Table 3.2.5. 3.2.7 The temporary flood standard during the construction period of the dam body should be determined according to the dam type and the flood control storage capacity in front of the dam according to Table 3.2.7. According to the impact on the downstream after the accident, the standard can be appropriately increased or decreased.1Flood standards for permanent hydraulic structures of water conservancy and hydropower projects in mountainous and hill
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