NB/T 11092-2023Technical code for deep tunnels of hydropower projects (English PDF)

Foreword

This document was issued on 6 February 2023 by the National Energy Administration of the PRC and takes effect on 6 August 2023.

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 code 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 Sector and the Plan for the Translation of Foreign Language Versions (Guo Neng Zong Tong Ke Ji [2022] No. 96).

The drafting group carried out extensive investigation and research, conscientiously summarized practical engineering experience, made reference to relevant advanced standards both in China and abroad, and prepared this code on the basis of soliciting opinions widely.

The main technical contents of this code are: general provisions; terms; basic requirements; geological investigation and evaluation; tunnel design; tunnel construction; prevention and treatment of geological risks; operation and maintenance; and digital application.

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

The Energy Industry Standardization Technical Committee for Hydropower Investigation and Design (NEA/TC15) is responsible for the interpretation of the specific technical contents of this code.

Comments and suggestions arising during the implementation of this code should be addressed to the China Renewable Energy Engineering Institute, No. 2 Liupukang Beixiaojie, Xicheng District, Beijing, postcode 100120.

Chief development organizations of this code: PowerChina Huadong Engineering Corporation Limited; China Renewable Energy Engineering Institute.

Participating development organizations of this code: PowerChina Chengdu Engineering Corporation Limited; PowerChina Kunming Engineering Corporation Limited; PowerChina Guiyang Engineering Corporation Limited; PowerChina Zhongnan Engineering Corporation Limited.

Further participating development organizations: Yalong River Hydropower Development Company Limited; Institute of Rock and Soil Mechanics, Chinese Academy of Sciences (Wuhan); Sinohydro Bureau 14 Company Limited.

Chief drafting personnel of this code: Zhang Chunsheng, Zhao Quansheng, Hou Jing, Xu Jianjun, Hao Jungang, Shan Zhigang, Zhou Chuiyi, Guo Decun.

Chief drafting personnel (continued): Chen Xiangrong, Zhang Yang, Wang Jilin, Chu Weijiang, Jia Haibo, Li Jun, Wang Yujie, Zhou Yong.

Chief drafting personnel (continued): Wu Jiayao, Jiang Hongjun, Xia Yong, Ning Yu, Wu Shuhuo, Liu Changgui, Ma Zhifeng, Zhou Hui.

Chief drafting personnel (continued): Duan Rujian, Zhang Chuanqing, Xu Jiangtao, Yue Chao, Bao Shihu, Liu Yue, Yang Xiaolong, Shen Xianzhu.

Chief drafting personnel (continued): Zhao Lu, Wei Baolong, Yan Dingcheng, Liu Ning, Wang Yongming, Chen Pingzhi, Huang Chengjia.

Chief review personnel of this code: Zhou Jianping, Mei Jinyu, Li Shisheng, He Wei, Wang Guojin, Sheng Qian, Shi Qingchun, Wu Chaoyue.

Chief review personnel (continued): Wang Huiming, Wang Jianhua, Ju Guanghong, Guo Weixiang, Ding Xiuli, Zhang Di, Wei Longhai, Jiao Pengcheng.

Announcement of the National Energy Administration

Announcement of the National Energy Administration, No. 1 of 2023.

In accordance with the Standardization Law of the People's Republic of China and the Measures for the Administration of Energy Standardization, the National Energy Administration approved 168 energy industry standards, headed by the Technical Code for High Voltage Direct Current Protection Testing Equipment (Annex 1).

The same announcement approved 20 foreign language versions of energy industry standards, headed by the Code for Design of Underground Steel Bifurcated Pipe with Crescent Rib of Hydropower Stations (Annex 2).

The announcement further approved one amendment notice to an energy industry standard, Asphalt for Waterproof Materials (Annex 3).

The annexes to the announcement are: 1. Catalogue of industry standards; 2. Catalogue of foreign language versions of industry standards; 3. Amendment notice of industry standards.

The announcement was issued by the National Energy Administration on 6 February 2023.

In the catalogue of industry standards attached to the announcement, this code is listed under serial number 42.

The catalogue entry records the standard number as NB/T 11092-2023 and the standard title as Technical Code for Deep Tunnels of Hydropower Projects.

The column for superseded standards in the catalogue entry is blank, so this code does not replace any earlier standard.

The column for the adopted international standard number is likewise blank, so this code is not an adoption of an international or foreign standard.

The catalogue entry gives the approval date as 6 February 2023 and the implementation date as 6 August 2023.

Approval and Publication Particulars

Full designation: NB/T 11092-2023, Technical Code for Deep Tunnels of Hydropower Projects, an energy industry standard of the People's Republic of China.

The cover classifies the code under ICS 27.140 and Chinese Standard Classification Code P 59, and carries the letter P denoting the engineering construction series.

The cover shows the issue date as 6 February 2023 and the implementation date as 6 August 2023, both under the seal of the National Energy Administration.

The title page names the chief administrative department as the China Renewable Energy Engineering Institute (General Institute of Hydropower and Water Resources Planning and Design).

The title page names the approving department as the National Energy Administration and repeats the date of entry into force as 6 August 2023.

The code was published by China Water and Power Press, Beijing, in 2023.

Publisher address as printed: Building D, No. 1 Yuyuantan South Road, Haidian District, Beijing, postcode 100038.

The printing record states a format of 140 mm by 203 mm, 32-mo format, 4 printed sheets and approximately 108 thousand characters.

The first edition and the first printing are both dated April 2023, with a print run of 1500 copies.

The book number is recorded as 155226-222 and the cover price as 105.00 yuan.

The publisher reserves all rights and states that infringement will be prosecuted; copies with missing, inverted or detached pages are exchanged by its marketing centre.

Scope and Application

The subject of the code is deep tunnels of hydropower projects, that is, tunnels driven under high overburden where depth-related conditions govern investigation, design and construction.

The code addresses the whole life of such a tunnel, from geological investigation and evaluation, through design and construction, to operation and maintenance.

It is an energy industry standard of the recommended type, as indicated by the letter T in the designation NB/T.

It applies within the hydropower sector administered by the National Energy Administration and is interpreted by NEA/TC15.

The code entered into force on 6 August 2023, six months after its approval on 6 February 2023.

As the catalogue entry records no superseded standard, the code is a first edition rather than a revision.

Users should read the code together with the current standards of the hydropower investigation and design series to which it belongs.

The English title printed on the cover, Technical Code for Deep Tunnels of Hydropower Projects, corresponds to the Chinese title and is used unchanged in this record.

1 Scope

NB/T 11092-2023 is the Chinese technical code for deep-buried tunnels on hydropower projects - headrace and tailrace tunnels, diversion and access tunnels driven under high rock cover, where depth itself changes the engineering problem. It covers the investigation such a tunnel needs, including the measurement of the in-situ stress field and the geothermal and hydrogeological survey, and the assessment of the hazards that come with depth: rockburst in hard brittle rock under high stress, large squeezing deformation in weak rock, high-pressure water inrush, gas, and high rock and water temperature. From that assessment it sets the alignment and section selection, the rock mass classification used at depth, and the design of support and lining - shotcrete and bolting, yielding support, steel sets, pre-stressed and reinforced concrete lining, and the grouting used for consolidation and for water control. Construction is treated in its own right: drill and blast versus tunnel boring machine, advance geological prediction ahead of the face, ventilation and cooling in a hot tunnel, drainage and pumping under high water pressure, and the safety measures against rockburst and inrush. The code then sets out monitoring during excavation and in service, the criteria for judging that the tunnel is stable, and the maintenance and inspection expected once the tunnel is operating, including the digital tools now used to manage that record. It applies to the design, construction and acceptance of deep tunnels on hydropower projects in China.

The body of the code is organized in nine chapters, as listed in the foreword and reflected in the table of contents.

Chapter 1, General Provisions, opens the code on page 1.

Chapter 2, Terms, begins on page 2 and defines the vocabulary used throughout the code.

Chapter 3, Basic Requirements, begins on page 4.

Chapter 4, Geological Investigation and Evaluation, begins on page 5 and is divided into four sections.

Chapter 5, Tunnel Design, begins on page 13 and is divided into nine sections, the largest chapter of the code.

Chapter 6, Tunnel Construction, begins on page 20 and is divided into four sections.

Chapter 7, Prevention and Treatment of Geological Risks, begins on page 24.

Chapter 8, Operation and Maintenance, is listed among the main technical contents in the foreword.

Chapter 9, Digital Application, closes the list of main technical contents given in the foreword.

The front matter is paginated in Roman numerals and comprises the announcement, its catalogue extract, the foreword and the table of contents.

The technical chapters are paginated in Arabic numerals starting from page 1.