NB/T 10209-2019Code for design of road for wind power projects (English PDF)

Foreword

This document was issued on 4 June 2019 by the National Energy Administration of the PRC and takes effect on 1 October 2019.

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 27.180, Chinese classification P 61.

In accordance with the requirements of the Notice of the National Energy Administration on Issuing the 2016 Plan for the Formulation and Revision of Energy Sector Industry Standards (Guoneng Keji [2016] No. 238), the drafting group conducted extensive investigation and research, carefully summarized practical experience and, on the basis of widely soliciting opinions, formulated this code.

The main technical contents of this code are: basic requirements, route selection, road alignment, subgrade, pavement, bridges, tunnels and culverts, and traffic engineering and roadside facilities.

The National Energy Administration is in charge of the administration of this code. China Renewable Energy Engineering Institute proposed the code and is responsible for its routine management, and the Wind Power Planning and Design Sub-committee of the Energy Industry Wind Power Standardization Technical Committee is responsible for the explanation of specific technical contents.

Comments or suggestions arising during implementation should be sent to China Renewable Energy Engineering Institute (address: No. 2 Liupukang Beixiaojie, Xicheng District, Beijing; postcode 100120).

Chief development organizations: PowerChina Beijing Engineering Corporation Limited; PowerChina Zhongnan Engineering Corporation Limited.

Chief drafting staff: Wu Chengzhi, Qin Xiaoming, Wang Dong, Zhang Qing, Yu Shaofeng, Fu Liangming, Wang Bin, Liu Xiaosong, Qi Zhicheng, Yan Biao, Li Shaopeng, Chen Guibin, Zhang Shijia, Zhao Zheng, Liu Mingxue, Luo Jianguo, Hu Yixin, Liu Guangming.

Chief reviewers include: Yi Yuechun, Shen Kuanyu, He Wei, Zhou Ena, Li Fagui, Zhou Caiquan, Yu Huafeng, Ma Fuxiang, Liu Yinhai, Gao Pengfei, Xue Jingjing, Ding Juntian, Lian Songtao, Wu Hupo, Chen Kangdong, Chen Shiqiang, Zhou He, Xu Changhong, Xie Hongwen, Chang Zuowei, Qing Huabin, Hu Xiaofeng, Du Gang, Li Shisheng.

Publication information

NB/T 10209-2019 is an energy industry standard of the People's Republic of China, published in the recommended (NB/T) series under the title Code for Design of Road for Wind Power Projects.

Classification on the cover: ICS 27.180; CCS P 61. The cover carries no reference to a superseded standard.

Issued on 2019-06-04 and implemented from 2019-10-01. Issued by the National Energy Administration.

Chief development department: China Renewable Energy Engineering Institute. Approval department: National Energy Administration. Implementation date: 1 October 2019. Published in Beijing, 2019.

The code was approved by National Energy Administration Announcement No. 4 of 2019, dated 4 June 2019, which approved and published 297 industry standards headed by the Code for Electrical Design of Photovoltaic Power Projects: 105 energy standards (NB), 168 electric power standards (DL) and 24 petrochemical standards (NB/SH).

In the list of industry standards attached to the announcement, this code appears as item 82: NB/T 10209-2019, Code for Design of Road for Wind Power Projects, with no superseded standard and no adopted international standard, approval date 2019-06-04 and implementation date 2019-10-01.

Structure of the complete code

Chapter 4, Route Selection (from page 8), comprises 4.1 General Requirements, 4.2 Principles and 4.3 Key Points.

Chapter 5, Road Alignment (from page 11), comprises 5.1 General Requirements, 5.2 Horizontal Alignment, 5.3 Vertical Alignment, 5.4 Alignment Design and 5.5 Road Intersection.

Chapter 6, Subgrade (from page 17), comprises 6.1 General Requirements, 6.2 Roadbed, 6.3 Embankment, 6.4 Excavation, 6.5 Subgrade Protection, 6.6 Subgrade Drainage, 6.7 Borrow Area and Spoil Area and 6.8 Widening of Subgrade.

Chapter 7, Pavement (from page 25), comprises 7.1 General Requirements, 7.2 Structures and Types of Pavement, 7.3 Combination Design of Pavement Structures and 7.4 Pavement Materials.

Chapter 8, Bridge, Tunnel and Culvert, begins on page 29.

Chapter 9, Traffic Engineering and Roadside Facilities (from page 31), comprises 9.1 General Requirements and 9.2 Laying Requirements.

The code closes with Appendix A, Calculation for Circular Curve Widening (page 33), the Explanation of Wording in This Code (page 37), the List of Quoted Standards (page 38) and the Addition: Explanation of Provisions (page 39).

1 Scope

NB/T 10209-2019 is the Chinese design code for the roads of wind farm projects. A wind farm road is a peculiar piece of highway engineering: it may carry very little traffic for twenty years, but during construction it must deliver blades longer than seventy metres, tower sections and nacelles weighing well over a hundred tonnes, and cranes of several hundred tonnes, often up mountain ridges. Its geometry is governed by the longest and heaviest load rather than by traffic volume. The code sets the general provisions and the defined terms, then the classification of wind farm roads into access roads, main internal roads, secondary internal roads and the substation road, and the design criteria for each. It covers route selection and the survey on which it rests, then the geometric design - horizontal curve radii and widening for long vehicles, gradients and the length of steep sections, vertical curves, cross sections and passing places - with the tables of limiting values and their notes. Subgrade design follows, with cut and fill slopes, drainage and protection, then pavement design for the construction loads and for the long operating period, and the bridges and culverts along the route. Turning areas and crane hardstands, traffic safety features, the treatment of the road after construction, and environmental protection and soil conservation close the code.

1.0.1 This code is formulated with a view to standardizing the design of roads for wind power projects.

1.0.2 This code is applicable to the design of roads for newly built, reconstructed and expanded wind power projects.

1.0.3 In addition to this code, the design of roads for wind power projects shall also comply with the provisions of the current relevant standards of the nation.

2 Terms

2.0.1 Access roads: roads connecting the local road network with the wind farm site.

2.0.2 Substation roads: roads connecting the local road network with the substation.

2.0.3 Main roads: roads serving as the principal transport corridors of the wind farm and carrying the larger share of transport tasks.

2.0.4 Feeder roads: roads serving as secondary transport corridors of the wind farm and carrying the smaller share of transport tasks.

3 Basic Requirements

3.1.1 The design of roads for wind power projects shall meet the requirements of construction and equipment transport during the construction period of the wind farm, and of inspection, repair and maintenance during the operation period.

3.1.2 According to the stage of use, roads for wind power projects may be divided into construction roads and maintenance roads; according to purpose, they may be divided into access roads, in-field roads and substation roads. According to transport volume, in-field roads may be divided into main roads and feeder roads. Access roads and substation roads shall be designed to the standard of main roads. Maintenance roads should be formed by upgrading construction roads.

3.1.3 The design speed of roads for wind power projects shall be 15 km/h.

3.1.4 The seismic design of roads for wind power projects shall comply with the relevant provisions of the current industry standard JTG B02, Specifications of Seismic Design for Highway Engineering.

3.1.5 The design of roads for wind power projects shall adopt economical and effective engineering or vegetation measures, so as to minimize adverse impacts of road construction on the ecological environment along the route.

3.2.1 In road design for wind power projects, the outline dimensions of the design vehicle shall be determined according to the type of transport vehicle selected, in accordance with Table 3.2.1 (Outline dimensions of design vehicles, in metres).

Table 3.2.1, construction period, 20 m tower-section transport semi-trailer: overall length 25.7, vehicle width 3.0, overall width 4.8, overall height 5.5, front overhang 1.2, wheelbase 4.5 + 15, rear overhang 5.

Table 3.2.1, construction period, 25 m tower-section transport semi-trailer: overall length 30.7, vehicle width 3.0, overall width 4.8, overall height 5.5, front overhang 1.2, wheelbase 4.5 + 18, rear overhang 7.

Table 3.2.1, construction period, 30 m tower-section transport semi-trailer: overall length 35.7, vehicle width 3.0, overall width 4.8, overall height 5.5, front overhang 1.2, wheelbase 4.5 + 22, rear overhang 8.

Table 3.2.1, construction period, 50 m blade transport semi-trailer: overall length 55.7, vehicle width 3.0, overall width 3.0, overall height 5, front overhang 1.2, wheelbase 4.5 + 22, rear overhang 28.

Table 3.2.1, construction period, 60 m blade transport semi-trailer: overall length 65.7, vehicle width 3.0, overall width 3.0, overall height 5, front overhang 1.2, wheelbase 4.5 + 28, rear overhang 32.

Table 3.2.1, construction period, 70 m blade transport semi-trailer: overall length 75.7, vehicle width 3.0, overall width 3.0, overall height 5, front overhang 1.2, wheelbase 4.5 + 35, rear overhang 35.

Table 3.2.1, construction period, hydraulic blade-lifting vehicle: overall length 22, vehicle width 3.0, overall width 3.0, overall height 5.5, front overhang 1.2, wheelbase 4.5 + 17.5, rear overhang not given.

Table 3.2.1, operation period, passenger car: overall length 6, vehicle width 1.8, overall width 1.8, overall height 2, front overhang 0.8, wheelbase 3.8, rear overhang 1.4.

Table 3.2.1, operation period, truck: overall length 12, vehicle width 2.5, overall width 2.5, overall height 4, front overhang 1.5, wheelbase 6.5, rear overhang 4.

Note to Table 3.2.1: the overall length and the rear overhang both include the length of the tower section or blade projecting beyond the trailer body.

3.2.2 The design load shall be the load specified in the current industry standard JTG B01, Technical Standard of Highway Engineering, and shall meet the following requirements:

3.2.2 item 1: the vehicle load shall be Highway Class II, and crowd load shall not be considered.

3.2.2 item 2: in bridge and culvert design, a vehicle load pattern consistent with the traffic composition of the road should be adopted for overall structural checking and local checking.

3.3.1 No obstacle shall intrude into the clearance boundary of the road.

3.3.2 The clearance boundary of the road (Figure 3.3.2) shall comply with the following provisions. In Figure 3.3.2, W is the maximum overall width of the transport vehicles, L is the lateral width, E is the top corner width of the clearance boundary and H is the clearance height.

3.3.2 item 1: where passing bays are provided, the clearance boundary shall include the width of that part.

3.3.2 item 2: where maintenance walkways or sidewalks are provided on bridges or in tunnels, the clearance boundary shall include the width of the corresponding part.

3.3.2 item 3: the clearance height of the carriageway shall be determined according to the maximum overall height of the transport vehicles, and a safety distance of 0.2 m to 0.5 m should be taken into account. Where a structure crosses above a sag vertical curve, the effective clearance height required by the transport vehicles shall be satisfied.

3.3.2 item 4: on superelevated sections, the upper boundary line shall be parallel to the superelevation cross slope, and the boundary lines on both sides shall be perpendicular to the superelevated cross slope of the pavement.

3.3.2 item 5: the minimum lateral width shall be 0.25 m. The top corner width of the clearance boundary shall be equal to the lateral width.

3.4.1 The cross section of the subgrade shall consist of the carriageway and the shoulders.

3.4.2 The subgrade width shall comply with the following provisions: item 1, roads for wind power projects shall adopt an integral subgrade; item 2, the subgrade width shall be the sum of the carriageway width and the widths of the shoulders on both sides, and the subgrade width of in-field construction roads shall comply with Table 3.4.2 (Subgrade width of in-field construction roads).

Table 3.4.2, main roads: general value, subgrade width 6.00 m, carriageway width 5.00 m, shoulder width on each side 0.50 m; limit value, subgrade width 5.50 m, carriageway width 5.00 m, shoulder width on each side 0.25 m.

Table 3.4.2, feeder roads: general value, subgrade width 5.00 m, carriageway width 4.00 m, shoulder width on each side 0.50 m; limit value, subgrade width 4.50 m, carriageway width 4.00 m, shoulder width on each side 0.25 m.

Note 1 to Table 3.4.2: the general value is the value adopted under normal conditions; the limit value is the value that may be adopted where conditions are restricted.

Note 2 to Table 3.4.2: where the outer side of the road is a steep slope or cliff, meets an unfavourable geological body, or the fill height is large, the width shall be appropriately increased.

Note 3 to Table 3.4.2: during design, the values shall be checked against the dimensions of the actual transport vehicles and equipment.

Note 4 to Table 3.4.2: the carriageway width of maintenance roads should not be less than 3.5 m.

3.4.3 In addition to meeting Table 3.4.2 of this code, the carriageway width shall also comply with the following provisions:

3.4.3 item 1: passing bays provided during the construction period shall be not less than 7.5 m wide, with an effective length of not less than 20 m and a transition length of not less than 10 m. The gradient of a passing bay should not exceed 5%. Passing bays should be located at favourable points at intervals not greater than 500 m.

3.4.3 item 2: where an emergency escape lane is provided, its width shall not be less than 4.0 m.

3.4.4 In addition to meeting Table 3.4.2 of this code, the shoulder width shall also comply with the following provisions:

3.4.4 item 1: earth shoulders should be adopted.

3.4.4 item 2: on straight sections or on the inside of curves, where the cross slope of the carriageway is greater than or equal to 3%, the cross slope of the earth shoulder shall be the same as that of the carriageway; where it is less than 3%, the cross slope of the earth shoulder shall be 1% or 2% greater than that of the carriageway. Earth shoulders on the outside of curves shall adopt a reverse cross slope of 3% or 4%.

3.5.1 Road land use shall follow the principles of protecting and developing land resources, using land rationally, effectively protecting cultivated land and promoting sustainable socio-economic development; the construction scale, technical indicators and design and construction scheme of the road shall be rationally determined, and the extent of road land shall be defined.

3.5.2 The extent of road land shall meet the following requirements:

3.5.2 item 1: the land within the outer edges of the side ditches on both sides, or within the toe of the embankment or of the berm slope where there is no side ditch, is the embankment land; the land within the outer edge of the intercepting ditch at the top of the slope, or within the top of the slope where there is no intercepting ditch, is the cutting land.

3.5.2 item 2: where the land extent needs to be enlarged for special reasons such as ensuring subgrade stability, an explanation shall be given.

3.5.2 item 3: the land for bridges, tunnels, storage yards, at-grade intersections, safety facilities and other off-line works shall be determined as required.

3.6.1 The design flood frequency of the subgrade shall be determined according to the degree of loss and impact following flood damage or failure.

3.6.2 The design flood frequency of bridges and culverts shall comply with Table 3.6.2: extra-large bridges 1/100; large bridges 1/50; medium bridges 1/50; small bridges 1/25; culverts and small drainage structures not specified.