NB/T 11670-2024Duration quotas for construction of hydropower projects (English PDF)

Foreword

This document was issued on 24 September 2024 by the National Energy Administration of the PRC and takes effect on 24 March 2025.

It is a NB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

It is classified under ICS 27.140, Chinese classification P 59.

This standard has been prepared in accordance with the requirements of the Notice of the General Department of the National Energy Administration on Issuing the 2022 Plan for the Development and Revision of Industry Standards in the Energy Field and the Plan for the Translation of Foreign Language Versions (Guo Neng Zong Tong Ke Ji [2022] No. 96).

In preparing this standard, the drafting group carried out extensive investigation and research, conscientiously summarized practical experience, and drew up the standard on the basis of a wide solicitation of opinions.

The main technical contents of this standard are: general provisions; terms; basic requirements; construction period of construction auxiliary works; construction period of construction diversion structures; construction period of roller-compacted embankment dams; construction period of concrete gravity dams; construction period of concrete arch dams; construction period of spillways; construction period of hydraulic tunnels; construction period of ground powerhouse civil works; construction period of underground powerhouse civil works; manufacturing and installation period of hydraulic steel structures; and the manufacturing, installation and commissioning periods of hydraulic turbine-generator units.

This standard is under the administration of the National Energy Administration. It was proposed by, and is under the routine management of, the China Renewable Energy Engineering Institute (General Institute of Hydropower and Water Resources Planning and Design).

The Sub-Technical Committee on Construction Design of the Energy Industry Standardization Technical Committee for Hydropower Investigation and Design (NEA/TC15/SC3) is responsible for the interpretation of the specific technical contents of this standard.

Comments and suggestions arising during the implementation of this standard should be addressed to the China Renewable Energy Engineering Institute (address: No. 57A and No. 57B Andingmenwai Street, Dongcheng District, Beijing, postal code 100011).

Chief development organization of this standard: China Renewable Energy Engineering Institute (General Institute of Hydropower and Water Resources Planning and Design).

Co-development organizations of this standard include POWERCHINA Beijing Engineering Corporation Limited, POWERCHINA Zhongnan Engineering Corporation Limited and POWERCHINA Kunming Engineering Corporation Limited.

Co-development organizations of this standard also include Sinohydro Bureau 14 Co., Ltd. and Sinohydro Bureau 8 Co., Ltd.

Co-development organizations of this standard further include POWERCHINA Northwest Engineering Corporation Limited, POWERCHINA Huadong Engineering Corporation Limited and Sinohydro Bureau 7 Co., Ltd.

Participating development organizations of this standard include Sinohydro Bureau 3 Co., Ltd., Sinohydro Bureau 6 Co., Ltd., China Power Construction Hydropower Development Group Co., Ltd. and POWERCHINA International Investment Co., Ltd.

Participating development organizations of this standard also include Sinohydro Bureau 1 Co., Ltd., Sinohydro Bureau 4 Co., Ltd., Sinohydro Bureau 5 Co., Ltd., Sinohydro Bureau 9 Co., Ltd. and Sinohydro Bureau 10 Co., Ltd.

Participating development organizations of this standard further include Sinohydro Bureau 11 Co., Ltd., Sinohydro Bureau 12 Co., Ltd., Sinohydro Bureau 15 Co., Ltd. and Sinohydro Bureau 16 Co., Ltd.

The foreword lists 39 principal drafters of this standard, whose names are printed in Chinese in the original edition.

The foreword also lists 18 principal reviewers of this standard, whose names are printed in Chinese in the original edition.

Publication Announcement

Announcement of the National Energy Administration, No. 3 of 2024.

In accordance with the Standardization Law of the People's Republic of China and the Administrative Measures for Energy Standardization, the National Energy Administration approved and issued 384 energy industry standards headed by Design Specification for Rock-fill Concrete Dams (Annex 1), 32 foreign language versions of energy industry standards headed by Operation Code for Liquefied Natural Gas Receiving Terminal (Annex 2), and 2 amendment notices for energy industry standards headed by Code for Geotechnical Monitoring of Hydropower Projects (Annex 3).

The annexes to the announcement are: 1. Catalogue of Industry Standards; 2. Catalogue of Foreign Language Versions of Industry Standards; 3. Amendment Notices for Industry Standards. The announcement is dated 24 September 2024.

In the Catalogue of Industry Standards this standard appears as serial number 75, standard code NB/T 11670-2024, with an approval date of 24 September 2024 and an implementation date of 24 March 2025. The columns for the superseded standard and for the adopted international standard are blank, so this standard does not replace any earlier standard and does not adopt an international standard.

The standard was prepared under the chief editing department, the China Renewable Energy Engineering Institute, approved by the National Energy Administration, and published by China Water and Power Press in Beijing in 2025, with an effective date of 24 March 2025.

Back Matter

Explanation of Wording in This Standard, on page 60, explains the degrees of strictness of the wording used in the provisions of the standard.

List of Quoted Standards, on pages 61 and 62, lists the standards quoted in this standard.

Addition: Explanation of Provisions, from page 63 onwards, is the clause-by-clause explanatory annex of the standard.

1 Scope

NB/T 11670-2024 is the Chinese quota document for construction duration on hydropower projects. Where a cost quota answers how much a unit of work costs, a duration quota answers how long it takes, and it is the reference against which a proposed programme is judged reasonable. The document sets out the general explanation first: the scope of the quotas, the conditions they assume, what is and is not included in a stated duration, and the adjustment coefficients applied when the real project differs from those conditions - by scale, by terrain and access, by climate and working season, by geological difficulty, or by the construction method chosen. It then gives the durations chapter by chapter across the work a hydropower project consists of: preparatory works and site access, river diversion, foundation excavation and treatment, the dam itself in its various types, powerhouse and switchyard, water conveyance tunnels and shafts, gates and hoists, the installation and commissioning of turbines, generators and electrical plant, and the reservoir filling and trial operation that close the project. Durations are given for the whole project by installed capacity and dam type, and for the individual stages, so that a programme can be built up or checked at either level. It is used by owners, designers and reviewers to set and assess construction schedules on hydropower projects in China.

1.0.1 This standard is formulated in order to standardize the preparation of the overall construction schedule of hydropower projects and to determine the construction duration of projects in a rational manner.

1.0.2 This standard is applicable to the establishment of the construction duration of hydropower engineering projects.

1.0.3 In addition to complying with this standard, duration quotas for the construction of hydropower engineering projects shall also comply with the provisions of the relevant current national standards.

2 Terms

2.0.1 Duration quota: the time standard consumed in completing the construction of an engineering project under normal construction conditions and with a rational construction organization.

2.0.2 Rational construction period: the planned construction period arranged for a hydropower project on the basis of the current average advanced construction level, taking comprehensive account of construction conditions such as geology, climate and environment, and under conditions of balanced resource allocation.

2.0.3 Pre-preparatory period: the construction period required to create the conditions for the commencement of the works.

During the pre-preparatory period the main tasks completed are the construction of the external access traffic works, the construction power supply works and the construction communication works, together with the land acquisition and resettlement of the construction area and the tendering and bidding work.

2.0.4 Preparatory period: the construction period from the commencement of the preparatory works to the point immediately before the commencement of the main works on the critical path.

During the preparatory period the main tasks completed are the construction of works such as site levelling, internal site traffic, the diversion works, the construction plants and the production and living facilities.

2.0.5 Construction period of main works: the construction period from the beginning of the construction of the main engineering items on the critical path until the first unit (or first batch of units) generates power or the project begins to produce benefits.

During the construction period of the main works the main tasks completed are the civil works of the permanent water-retaining structures, the water-release structures and the water conveyance and power generation structures, together with the installation and commissioning of their hydraulic steel structures and electromechanical equipment, and the other construction of the main works.

2.0.6 Completion period: the construction period from the moment the first unit (or first batch of units) is put into operation or the project begins to produce benefits until the completion of the works.

During the completion period the main tasks completed are the installation and commissioning of the subsequent units, the remaining work on the water-retaining structures, the water-release structures and the water conveyance and power generation structures, and the closure of the diversion and water-release structures.

3 Basic Requirements

Clause 3, Basic Requirements, begins on page 3 of the standard and continues up to the start of Clause 4 on page 5; it sets out the requirements that govern the application of the duration quotas given in Clauses 4 to 14.

4 Construction Period of Construction Auxiliary Works

Clause 4 covers the construction period of the construction auxiliary works and runs from page 5 to page 9, divided into nine subclauses.

4.1 General Requirements, on page 5, gives the general rules for applying the duration quotas of the construction auxiliary works.

4.2 Construction Period of Aggregate Processing System, on page 5, gives the duration quota for the aggregate (sand and gravel) processing system.

4.3 Construction Period of Concrete Production System, on page 6, gives the duration quota for the concrete production system.

4.4 Construction Period of Construction Water Supply Works, on page 6, gives the duration quota for the construction water supply system.

4.5 Construction Period of Construction Power Supply Works, on page 7, gives the duration quota for the construction power supply system.

4.6 Construction Period of Penstock Fabrication Plant, on page 7, gives the duration quota for the steel penstock fabrication plant.

4.7 Construction Period of Runner Assembly Plant, on page 8, gives the duration quota for the turbine runner processing and assembly plant.

4.8 Construction Period of Access Roads, on page 8, gives the duration quota for the traffic and access road works.

4.9 Construction Period of Construction Camps, on page 9, gives the duration quota for the construction camp facilities.

5 Construction Period of Construction Diversion Structures

Clause 5 covers the construction period of the construction diversion structures and runs from page 10 to page 16, divided into four subclauses.

5.1 General Requirements, on page 10, gives the general rules for applying the duration quotas of the diversion structures.

5.2 Construction Period of Diversion Tunnel, from page 10 to page 12, gives the duration quotas for diversion tunnels.

5.3 Construction Period of Diversion Canal, on page 13, gives the duration quotas for open diversion canals.

5.4 Construction Period of Cofferdams, from page 14 to page 16, gives the duration quotas for cofferdams.

6 Construction Period of Roller-Compacted Embankment Dam

Clause 6 covers the construction period of roller-compacted earth-rock (embankment) dams and runs from page 17 to page 24, divided into eight subclauses.

6.1 General Requirements, on page 17, gives the general rules for applying the duration quotas of roller-compacted embankment dams.

6.2 Construction Period of Ground Excavation and Support Works, on page 17, gives the duration quotas for excavation and support of the dam foundation.

6.3 Construction Period of Ground Treatment Works, from page 18 to page 19, gives the duration quotas for dam foundation treatment.

6.4 Construction Period of Central or Sloping Clay Core Rockfill Dam, on page 20, gives the duration quotas for placing rockfill dams with an earth core wall or an inclined earth core.

6.5 Construction Period of Asphalt Concrete Core Rockfill Dam, on page 21, gives the duration quotas for placing rockfill dams with an asphalt concrete core wall.

6.6 Construction Period of Face Rockfill Dam, from page 21 to page 22, gives the duration quotas for placing face rockfill dams.

6.7 Construction Period of Reinforced Concrete Face, on page 23, gives the duration quotas for the reinforced concrete face slab.

6.8 Construction Period of Asphalt Concrete Face, on page 23, gives the duration quotas for the asphalt concrete face.

7 Construction Period of Concrete Gravity Dam

Clause 7 covers the construction period of concrete gravity dams and runs from page 25 to page 28, divided into four subclauses.

7.1 General Requirements, on page 25, gives the general rules for applying the duration quotas of concrete gravity dams.

7.2 Construction Period of Ground Excavation and Support Works, on page 25, gives the duration quotas for excavation and support of the dam foundation.

7.3 Construction Period of Ground Treatment Works, on page 26, gives the duration quotas for dam foundation treatment.

7.4 Construction Period of Concrete Pouring Works, from page 27 to page 28, gives the duration quotas for placing the concrete of the gravity dam.

8 Construction Period of Concrete Arch Dam

Clause 8 covers the construction period of concrete arch dams and runs from page 29 to page 32, divided into four subclauses.

8.1 General Requirements, on page 29, gives the general rules for applying the duration quotas of concrete arch dams.

8.2 Construction Period of Ground Excavation and Support Works, on page 29, gives the duration quotas for excavation and support of the dam foundation.

8.3 Construction Period of Ground Treatment Works, on page 30, gives the duration quotas for dam foundation treatment.

8.4 Construction Period of Concrete Pouring Works, from page 31 to page 32, gives the duration quotas for placing the concrete of the arch dam.

9 Construction Period of Spillway

Clause 9 covers the construction period of the spillway and runs from page 33 to page 34; unlike the other structural clauses it is not divided into subclauses.

10 Construction Period of Hydraulic Tunnel

Clause 10 covers the construction period of hydraulic tunnels and runs from page 35 to page 40, divided into six subclauses.

10.1 General Requirements, on page 35, gives the general rules for applying the duration quotas of hydraulic tunnels.

10.2 Construction Period of Portals, on page 35, gives the duration quotas for the inlet and outlet portals.

10.3 Construction Period of Horizontal Section Excavation and Support Works, from page 36 to page 37, gives the duration quotas for excavation and support of the horizontal tunnel sections.

10.4 Construction Period of Inclined/Vertical Shaft Excavation and Support Works, on page 38, gives the duration quotas for excavation and support of inclined shafts and vertical shafts.

10.5 Construction Period of Horizontal Section Concrete Lining Works, on page 39, gives the duration quotas for the concrete lining of the horizontal tunnel sections.

10.6 Construction Period of Inclined/Vertical Shaft Concrete Lining Works, on page 40, gives the duration quotas for the concrete lining of inclined shafts and vertical shafts.

11 Construction Period of Ground Powerhouse Civil Works

Clause 11 covers the construction period of the civil works of surface (ground) powerhouses and runs from page 41 to page 43, divided into three subclauses.

11.1 General Requirements, on page 41, gives the general rules for applying the duration quotas of ground powerhouse civil works.

11.2 Construction Period of Ground Excavation and Support Works, on page 41, gives the duration quotas for excavation and support of the powerhouse foundation.

11.3 Construction Period of Concrete Pouring Works, from page 42 to page 43, gives the duration quotas for placing the concrete of the ground powerhouse.

12 Construction Period of Underground Powerhouse Civil Works

Clause 12 covers the construction period of the civil works of underground powerhouses and runs from page 44 to page 48, divided into five subclauses.

12.1 General Requirements, on page 44, gives the general rules for applying the duration quotas of underground powerhouse civil works.

12.2 Construction Period of Excavation and Support Works for Underground Powerhouse of Conventional Hydropower Station, on page 44, gives the duration quotas for excavation and support of the underground powerhouse of a conventional hydropower station.

12.3 Construction Period of Excavation and Support Works for Underground Powerhouse of Pumped Storage Power Station, on page 45, gives the duration quotas for excavation and support of the underground powerhouse of a pumped storage power station.

12.4 Construction Period of Concrete Pouring Works for Underground Powerhouse of Hydropower Station, from page 46 to page 47, gives the duration quotas for placing the concrete of the underground powerhouse of a hydropower station.

12.5 Construction Period of Concrete Pouring Works for Underground Powerhouse of Pumped Storage Power Station, on page 48, gives the duration quotas for placing the concrete of the underground powerhouse of a pumped storage power station.

13 Manufacturing and Installation Period of Hydraulic Steel Structures

Clause 13 covers the manufacturing and installation period of hydraulic steel structures and runs from page 49 to page 53, divided into four subclauses.

13.1 General Requirements, on page 49, gives the general rules for applying the manufacturing and installation quotas of hydraulic steel structures.

13.2 Manufacturing and Installation Period of Gates and Hoists, from page 49 to page 50, gives the quotas for the manufacture and installation of gates and hoists.

13.3 Manufacturing and Installation Period of Gantry Crane and Bridge Crane, on page 51, gives the quotas for the manufacture and installation of gantry cranes and bridge cranes.

13.4 Installation Period of Penstocks and Steel Linings, from page 52 to page 53, gives the quotas for the installation of steel penstocks and steel linings.

14 Manufacturing, Installation and Commissioning Periods of Hydraulic Turbine-Generator Units

Clause 14 covers the manufacturing, installation and commissioning periods of hydraulic turbine-generator units and runs from page 54 to page 59, divided into three subclauses.

14.1 General Requirements, on page 54, gives the general rules for applying the quotas of turbine-generator units.

14.2 Manufacturing Period of Hydraulic Turbine-Generator Units, from page 54 to page 55, gives the manufacturing cycle quotas for the units.

14.3 Installation and Commissioning Period of Hydraulic Turbine-Generator Units, from page 56 to page 59, gives the quotas for the installation and commissioning of the units.