NB/T 32047-2018Standard for quality assessment of civil engineering construction unit of photovoltaic power station (English PDF)

Foreword

This document was issued on 6 June 2018 by the National Energy Administration of the PRC and takes effect on 1 October 2018.

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 27.160, Chinese classification P 61.

This standard has been formulated in accordance with the requirements of the Notice of the National Energy Administration on Issuing the Second Batch of Plans for the Formulation (Revision) of Industry Standards in the Energy Field for 2014 (Guo Neng Ke Ji [2015] No. 12).

During the preparation of this standard, extensive investigation, research and thematic discussions were carried out; the practical experience of civil engineering construction of photovoltaic power stations in China was comprehensively summarised; relevant domestic and international materials were consulted; and, on the basis of soliciting the opinions of all parties involved in engineering construction, the final draft was settled after examination.

The main contents of this standard cover earth and stone excavation and backfilling, foundations for photovoltaic module supports, buildings and structures, cable pipe trenches, water supply and drainage of the site area, and roads of the site area.

Chief editing organisation of this standard: Sinohydro Bureau 4 Co., Ltd. (China Water Resources and Hydropower Fourth Engineering Bureau Co., Ltd.).

Participating editing organisations of this standard: PowerChina Construction Group Co., Ltd.; Beijing Guodian Desheng Engineering Project Management Co., Ltd.; Changzhou Huayang Photovoltaic Testing Technology Co., Ltd.; Norseman Energy Technology (Beijing) Co., Ltd.

Chief drafters of this standard: Xi Hao, Zhang Wenshan, Li Kexin, Niu Hongli, Li Guixing, Liang Guohui, Zhang Shengtong, Chen Tao, Wu Chunqiu, Jiang Shengwang, Zhang Zidong, Fang Caixia, Dong Shida, Liang Hongsheng, Xie Xiaotuo, Du Ruirui, Luo Weicheng, Jiao Kuihang, Gao Chao, Zhou Yan, Gu Xixue, Cheng Ji, Jing Xiaoqing.

Chief reviewers of this standard: Zhang Shusen, Xu Songlin, Wang Yi, Zhang Xueli, Shi Wengang, Li Aiwu, Zhao Hui, Yi Jinyin, Shao Qiukui, Jiang Hongsheng, Dong Kaisong, Niu Ruijie, Lu Hai, Chai Haidi, Tian Yucheng.

Comments and suggestions arising during the implementation of this standard should be fed back to the Standardization Management Centre of the China Electricity Council (No. 1, Baiguanglu Ertiao, Beijing, 100761).

Publication information

Energy industry standard of the People's Republic of China. NB/T 32047-2018, Standard for quality assessment of civil engineering construction unit of photovoltaic power station. ICS 27.160, classification code P 61, record (filing) number 64675-2018.

Chief editing organization: China Electricity Council. Approving department: National Energy Administration. Date of implementation: 1 October 2018. Published by China Electric Power Press, Beijing, 2018.

National Energy Administration Announcement No. 8 of 2018: in accordance with the relevant provisions of the Notice of the National Energy Administration on Issuing the Measures for the Administration of Standardization in the Energy Field (Trial) and their Implementing Rules (Guo Neng Ju Ke Ji [2009] No. 52), and after examination, the National Energy Administration approved 87 industry standards including Quality Control Requirements for the Directional Well Bore of Coalbed Methane Wells, among which 47 are energy standards (NB) and 40 are electric power standards (DL), and hereby issues them.

Attachment, catalogue of industry standards, item 86: standard number NB/T 32047-2018, standard name Standard for quality assessment of civil engineering construction unit of photovoltaic power station, no superseded standard, no adopted-standard number, date of approval 2018-06-06, date of implementation 2018-10-01. Issued by the National Energy Administration on 6 June 2018.

1 Scope

NB/T 32047-2018 sets out how the civil works of a photovoltaic power station are assessed for quality, unit of work by unit of work. A solar plant is civil engineering spread thin over a large area - thousands of module support foundations, access roads, cable trenches, inverter and transformer stations, control buildings, drainage and perimeter walls - and the standard turns that into a countable inspection scheme. It defines the unit of work and how a site is divided into them, the inspection lots within each, and the grades of assessment with the pass thresholds at each level. It then gives the assessment content and the tables of checkpoints for each type of work: earthworks and site preparation, cast-in-place and precast foundations for the module arrays, anchor and pile foundations including their installation tolerances, concrete and reinforcement work, buildings and structures, roads and hardstanding, cable trenches and ducts, drainage, and perimeter walls and fencing. For each checkpoint it states the permitted deviation, the measuring method and the number of measurements required, so that two assessors reach the same result from the same site. The treatment of non-conforming lots, the records to be kept, and the form of the assessment report complete the document. Owners, contractors and supervising engineers use it during construction and at acceptance of photovoltaic plants in China.

1.0.1 This standard is formulated in order to standardise the assessment of the construction quality of unit projects of civil engineering works of photovoltaic power stations.

1.0.2 This standard is applicable to the civil engineering works of newly built, rebuilt and extended ground-mounted photovoltaic power stations.

1.0.3 The construction unit (contractor) shall establish a construction quality management system and a quality inspection system.

1.0.4 In addition to complying with this standard, the acceptance and quality assessment of the construction quality of civil engineering works of photovoltaic power generation shall also comply with the provisions of the relevant current national standards.

2 Terms

2.0.1 photovoltaic power station: a power station in which the photovoltaic power generation system is the main part, and which includes all kinds of buildings and structures together with auxiliary facilities for overhaul, maintenance and daily living.

2.0.2 unit project: according to the requirements of design, construction or quality assessment, a building is divided into a number of layers, blocks, zones, sections and the like; a unit project is usually a complex completed through several working procedures, and it is also the basic unit for assessing the quality of the construction process.

2.0.3 major control items: inspection items that play a decisive role in the function of the unit project, or that have a significant influence on safety, health or the environment.

2.0.4 general project (general items): inspection and testing items other than the major control items.

2.0.5 PV module bracket: the special-purpose bracket designed in a photovoltaic power generation system for placing, installing and fixing the photovoltaic modules.

3 Basic requirements

3.0.1 The division of unit projects shall be carried out according to the construction category of the project and the characteristics of the project.

3.0.2 The quality inspection items of a unit project shall be divided into major control items and general items.

3.0.3 The assessment of the quality grade of a unit project shall satisfy the following conditions:

3.0.3-1 All construction operations of the unit project have been completed.

3.0.3-2 The contractor has completed the self-inspection of the construction quality of the unit project in accordance with this standard, has filled in the quality acceptance documents of the unit project, and has applied to the supervision organisation for acceptance.

3.0.3-3 The quality inspection of raw materials, structural components (fittings), intermediate products and working procedures is qualified, and the inspection documents are complete and comply with the prescribed format.

3.0.3-4 The sampling frequency and the quantity of raw materials, structural components (fittings) and intermediate products comply with the relevant standards or provisions.

3.0.3-5 If, because of special circumstances, some items cannot be inspected in time, a provisional assessment with missing items shall be made, and the final assessment shall be made after the missing items have been completed.

3.0.4 The assessment of the construction quality grade of a unit project shall meet the following basic requirements:

3.0.4-1 Qualified (pass): the inspection results of all major control items comply with the requirements; for the general items, item by item, 70 per cent or more of the inspection points are qualified, and the unqualified points are not concentrated.

3.0.4-2 Excellent (good): the inspection results of all major control items comply with the requirements; for the general items, item by item, 90 per cent or more of the inspection points are qualified, and the unqualified points are not concentrated.

3.0.5 The assessment of the quality grade of a unit project shall produce the following documents:

3.0.5-1 The unit project quality assessment form on which the quality grade has been confirmed.

3.0.5-2 The quality inspection documents of raw materials, structural components (fittings) or intermediate products, complying with the prescribed format, complete, and signed and confirmed by the supervision organisation.

3.0.5-3 The quality inspection documents of the working procedures, complying with the prescribed format, complete, and signed and confirmed by the supervision organisation.

4 Earthwork and foundation pit engineering

4.1 General requirement

4.1.1 The quality assessment of earth and stone works is applicable to earth and stone excavation works and backfilling works.

4.1.2 Earth and stone works shall be assessed in accordance with the Technical Code for Building Slope Engineering GB 50330, the Code for Construction and Acceptance of Earthwork and Blasting Engineering GB 50201, and the design requirements.

4.1.3 The division of earth and stone unit projects follows the division into construction inspection and acceptance zones and sections; each zone or section constitutes one unit project.

4.2 Earthwork excavation

4.2.1 The quality assessment of earthwork excavation shall meet the following requirements:

4.2.1-1 Major control items:

4.2.1-1-1) The length, width and elevation of foundation pits shall be inspected in full; not fewer than 3 points for each foundation pit.

4.2.1-1-2) For the length, width and elevation of foundation trenches and pipe trenches, 2 points shall be sampled for every 10 linear metres; where the length is less than 10 m, not fewer than 2 points.

4.2.1-1-3) The surface elevation of the site after levelling shall be inspected point by point; the inspection points shall be taken as 3 points for every 100 square metres, and not fewer than 3 points where the area is less than 100 square metres.

4.2.1-1-4) Where the length of the pipe trench exceeds 500 m, not fewer than 5 points per 100 m; where the length of the pipe trench is less than 500 m, not fewer than 3 points per 100 m.

4.2.1-2 General items:

4.2.1-2-1) For the flatness inspection of foundation pits, 1 location shall be sampled for every 10 square metres; where the area is less than 10 square metres, not fewer than 1 location.

4.2.1-2-2) For the flatness inspection of foundation trenches and pipe trenches, 1 location shall be sampled for every 20 linear metres; where the length is less than 20 m, not fewer than 1 location.

4.2.1-2-3) For the site surface after levelling, 1 location shall be taken for every 100 square metres; where the area is less than 100 square metres, not fewer than 1 location.

4.2.1-2-4) For the slope gradient, 1 location shall be taken for every 20 linear metres; not fewer than 1 location on each side.

4.2.2 The quality standards and inspection methods for earthwork excavation works shall comply with the provisions of Table 4.2.2, Quality standards and inspection methods for earthwork excavation works.

Table 4.2.2, major control item 1, elevation: foundation pit and foundation trench, minus 50 to 0 mm; site levelling by manual work, plus or minus 30 mm; site levelling by machine, plus or minus 50 mm; pipe trench, minus 50 to 0 mm; ground (road) surface base course, minus 50 to 0 mm; inspection by level instrument.

Table 4.2.2, major control item 2, length and width (measured from the design centre line towards both sides): foundation pit and foundation trench, minus 50 to 100 mm; excavated site levelling by manual work, minus 100 to 300 mm; excavated site levelling by machine, minus 150 to 500 mm; pipe trench, 0 to 50 mm; inspection by total station and steel tape.

Table 4.2.2, general item 1, surface flatness: foundation pit and foundation trench, not more than 20 mm; excavated site levelling by manual work, not more than 20 mm; excavated site levelling by machine, not more than 50 mm; pipe trench, not more than 20 mm; ground (road) surface base course, not more than 20 mm; unit mm; inspection with straightedge and wedge-shaped feeler gauge.

Table 4.2.2, general item 2, slope gradient: not steeper than the design slope; inspection by observation or with a slope gauge.

4.2.3 The quality assessment of earthwork excavation works shall comply with the relevant requirements of Table A.0.1 of Appendix A.

4.3 Earthwork backfilling

4.3.1 The quality assessment of earthwork backfilling shall meet the following requirements:

4.3.1-1 Major control items:

4.3.1-1-1) The treatment of the base (foundation bed) shall be inspected in full.

4.3.1-1-2) For the slope gradient, 1 location shall be taken every 5 m; where the length is less than 5 m, not fewer than 1 location.

4.3.1-1-3) For the elevation of foundation pits, 1 point shall be sampled for every 10 square metres; where the area is less than 10 square metres, not fewer than 1 point.

4.3.1-1-4) For the elevation of foundation trenches and pipe trenches, 1 point shall be sampled for every 10 linear metres; where the length is less than 10 m, not fewer than 1 point.

4.3.1-1-5) For the site surface after backfilling, 3 points shall be taken for every 100 square metres; where the area is less than 100 square metres, not fewer than 3 points.

4.3.1-1-6) For the compaction degree of site levelling, 1 group shall be taken per layer for every 100 square metres; where the area is less than 100 square metres, not fewer than 1 group.

4.3.1-2 General items:

4.3.1-2-1) The backfill soil material shall be inspected in full.

4.3.1-2-2) Layer thickness and moisture content: the filling thickness of each layer and the number of compaction passes shall be determined according to the soil quality, the compaction coefficient and the equipment used; where the design gives no requirement, the current relevant standards shall be followed.

4.3.1-2-3) For the flatness of foundation pits, 1 location shall be sampled for every 10 square metres; where the area is less than 10 square metres, not fewer than 1 location.

4.3.1-2-4) For the flatness of foundation trenches and pipe trenches, 1 location shall be sampled for every 10 linear metres; where the length is less than 10 m, not fewer than 1 location.

4.3.1-2-5) For the site surface after levelling, 1 location shall be taken for every 100 square metres; where the area is less than 100 square metres, not fewer than 1 location.

4.3.2 The quality standards and inspection methods for earthwork backfilling works shall comply with the provisions of Table 4.3.2, Quality standards and inspection methods for earthwork backfilling works.

Table 4.3.2, major control item 1, treatment of the base (foundation bed): design requirements; inspection by observation and by checking the test records.

Table 4.3.2, major control item 2, slope gradient: design requirements; inspection by observation or with a slope gauge.

Table 4.3.2, major control item 3, elevation: foundation pit and foundation trench, minus 30 to 0 mm; site levelling by manual work, plus or minus 20 mm; site levelling by machine, plus or minus 30 mm; pipe trench, minus 30 to 0 mm; ground (road) surface base course, minus 30 to 0 mm; unit mm; inspection by level instrument.

Table 4.3.2, major control item 4, layered compaction coefficient: design requirements; inspection by checking the test records.

Table 4.3.2, general item 1, backfill soil material: design requirements; inspection by observation or by sampling test.

Table 4.3.2, general item 2, layer thickness: plus or minus 30 mm; inspection by level instrument and by checking the test records.

Table 4.3.2, general item 3, surface flatness: foundation pit and foundation trench, not more than 20 mm; site levelling by manual work, not more than 20 mm; site levelling by machine, not more than 50 mm; pipe trench, not more than 20 mm; ground (road) surface base course, not more than 20 mm; unit mm; inspection with straightedge and string line.

4.3.3 The quality assessment of earthwork backfilling works shall comply with the relevant requirements of Table A.0.2 of Appendix A.

4.4 Stonework excavation

4.4.1 The quality assessment of stonework excavation shall meet the following requirements:

4.4.1-1 Major control item: the rock quality of the base shall be inspected in full.

4.4.1-2 General items:

4.4.1-2-1) The elevation of foundation pits shall be inspected in full; not fewer than 2 points for each foundation pit.

4.4.1-2-2) For the elevation of foundation trenches and pipe trenches, 1 point shall be sampled for every 20 linear metres; where the length is less than 20 m, not fewer than 1 point.

4.4.1-2-3) For the flatness of the excavated face, 1 location shall be sampled for every 100 square metres; where the area is less than 100 square metres, not fewer than 1 location.

4.4.2 The quality standards and inspection methods for stonework excavation works shall comply with the provisions of Table 4.4.2, Quality standards and inspection methods for stonework excavation works.

Table 4.4.2, major control item 1, rock quality of the base: design requirements; inspection by observation and by checking the test records.

Table 4.4.2, major control item 2, slope gradient: design requirements; inspection with a slope gauge.

Table 4.4.2, general item 1, deviation of top elevation: foundation pit, foundation trench and pipe trench, 0 to 50 mm; site levelling, plus or minus 50 mm; unit mm; inspection by level instrument.

Table 4.4.2, general item 2, deviation of geometric dimensions: foundation pit, foundation trench and pipe trench, 0 to 50 mm; unit mm; inspection by tape measurement.

4.4.3 The quality assessment of stonework excavation works shall comply with the relevant requirements of Table A.0.3 of Appendix A.

5 Photovoltaic modules support base

5.1 General requirement.

5.2 Screw pile.

5.3 Cast-in-place pile.

5.4 Prestressed concrete pipe pile and precast concrete pile.

5.5 Shape steel pile.

5.6 Extended foundation.

5.7 Anchor foundation.

6 Building

6.1 General requirement.

6.2 Complex building project.

6.3 Wall (fence) engineering.

6.4 Entrance door engineering.

7 Cable pipe trench

7.1 General requirement.

7.2 Brick pipe trench.

7.3 Concrete pipe trench.

7.4 Concrete cover plate project.

7.5 Steel cover plate works.

8 Water supply and drainage

8.1 General requirement.

8.2 Outdoor water supply pipe installation.

8.3 Drainage pipe network installation.

9 Field road

9.1 General requirement.

9.2 Subgrade.

9.3 Pavement foundation.

9.4 Surface course.

9.5 Curb.

A Appendix A Quality evaluation form of civil engineering construction unit of photovoltaic power station

Appendix A gives the quality evaluation forms of the civil engineering construction units of photovoltaic power stations, starting at page 72, including Table A.0.1 for earthwork excavation works, Table A.0.2 for earthwork backfilling works and Table A.0.3 for stonework excavation works, which are referred to by clauses 4.2.3, 4.3.3 and 4.4.3.

The standard is completed by the Explanation of wording in this standard, the List of quoted standards, and the Addition, Explanations of provisions.