NB/T 10333-2019Code for design of on-site roads for hydropower projects (English PDF)

Foreword

This document was issued on 30 December 2019 by the National Energy Administration of the PRC and takes effect on 1 July 2020.

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 P59.

It replaces DL/T 5134-2001, which is superseded.

NB/T 10333-2019 is an energy industry standard of the People's Republic of China, issued by the National Energy Administration on 2019-12-30 and implemented from 2020-07-01. It supersedes DL/T 5134-2001.

In accordance with the requirements of the Notice of the National Energy Administration on Issuing the First Batch of Energy Sector Standard Formulation (Revision) Plans for 2009 (Guo Neng Ke Ji [2009] No. 163) and the Notice of the National Energy Administration on Issuing the Second Batch of Energy Sector Standard Formulation (Revision) Plans for 2012 (Guo Neng Ke Ji [2012] No. 326), the drafting group revised this code after extensive investigation and research, careful summarization of practical experience, reference to relevant national standards and wide solicitation of opinions.

The main technical contents of this code are: on-site road planning; route; subgrade and pavement; bridge and culvert; tunnel; safety facilities, environmental protection and soil and water conservation.

Main revision: the terms have been added.

Main revision: provisions on the design of the route, subgrade and pavement, bridge and culvert, tunnel, safety facilities, environmental protection and soil and water conservation have been added.

Main revision: Appendix A, on the combination of action effects of special checking loads, has been added.

Main revision: the former provisions on basic design data and on external access transport have been deleted.

Main revision: the former Appendix A to Appendix D have been deleted.

This code is under the administration of the National Energy Administration. China Renewable Energy Engineering Institute proposed it and is responsible for its routine management, and the Nengyuan Hangye Shuidian Kance Sheji Biaozhunhua Jishu Weiyuanhui (energy industry standardization technical committee for hydropower survey and design) is responsible for the interpretation of its specific technical contents.

Any 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 drafting organizations: PowerChina Chengdu Engineering Corporation Limited; China Renewable Energy Engineering Institute; PowerChina Zhongnan Engineering Corporation Limited.

Chief drafting staff: Fu Zhiqian, Zeng Jianjun, Nie Dafeng, Xiao Changqing, Long Wei, He Wei, Qing Huabin, Zhang Dan, Li Yi, Mao Suifeng, You Xuancheng, Ma Jianxin, Chen Weitao, Liu Zhiyong, Zhou Chungen, Hong Wen, He Junqiao.

Chief reviewers: Wei Zhiyuan, Yu Kui, Lu Zhaoqin, Shi Qingchun, Ren Jinming, Chun Guangkui, Huang Liefu, Xie Chunsheng, Li Hongxiang, Dai Zhenfeng, Tang Feixiong, Hu Jianhua, Luo Lin, Ding Yan, Yang Pengfei, Zhou Shaohong, Zhou Zhengguo, Zhang Guoliang, Lu Kunhua, Ma Zhiguo, Yin Xianjun, Zhao Tie, Li Shisheng.

1 Scope

NB/T 10333-2019 is the Chinese design code for the on-site roads of hydropower projects, replacing DL/T 5134-2001. The internal road network of a large dam site carries more tonnage than most public highways ever will: fleets of heavy dump trucks moving fill and aggregate, concrete trucks running between batching plant and placement, and transport vehicles carrying turbine runners, transformers and gate leaves weighing hundreds of tonnes - on steep valley sides, often through tunnels, for a decade of construction. The code sets the general provisions and defined terms, then the planning of the network: the division into main and secondary roads, the classification of roads by traffic and by the heaviest vehicle, and the clearance gauges. It covers route selection and alignment design, with horizontal and vertical geometry tabulated by road class and the limits for switchbacks and long steep grades. Subgrade design follows, with cuts, fills and retaining structures on steep slopes and their drainage, then pavement design for heavy haulage. Bridges, including those designed for special heavy transport loads, and road tunnels with their lining, ventilation and lighting have their own chapters. Traffic safety facilities, environmental protection and the conversion of construction roads to permanent use close the code.

1.0.1 This code is formulated with a view to standardizing the design of on-site roads for hydropower projects.

1.0.2 This code is applicable to the design of on-site roads for hydropower projects.

1.0.3 On-site roads for hydropower projects shall be planned in an overall manner and arranged reasonably so as to meet the traffic and transport needs of hydropower project construction and operation. Road design shall be safe and fit for purpose, technically advanced and economically reasonable, and shall comply with the requirements of environmental protection, soil and water conservation, and energy saving and consumption reduction.

1.0.4 In addition to this code, the design of on-site roads for hydropower projects shall also comply with the current relevant national standards.

2 Terms

2.0.1 on-site road: road built for the construction and the operation management of a hydropower project, which connects the headworks structures with the main construction work areas, material sources, spoil disposal areas and production and living areas inside the project area, and which carries the construction transport inside the project area and the transport for the operation management of the power station.

2.0.2 on-site major road: on-site road connecting the main headworks structures of a hydropower project with the main construction work areas, material sources, spoil disposal areas and production and living areas.

2.0.3 on-site minor road: on-site road connecting the major roads with the construction work faces.

2.0.4 vehicle line load: vehicle load formed by the main vehicle types used for transport during the construction period of a hydropower project, arranged in a specified pattern.

3 On-site road planning

3.1.1 The planning of on-site roads shall reasonably arrange the roads serving structure construction, material sources, spoil disposal areas, main auxiliary construction facilities, production and living areas, etc., according to the requirements that the headworks layout, the general construction layout and the overall construction schedule of the hydropower project place on on-site transport, and shall make reasonable use of existing roads.

3.1.2 The planning of on-site roads shall meet the transport requirements for heavy and oversize items such as electromechanical equipment, metal structures and construction machinery, and shall be reasonably connected with the external access transport.

3.1.3 On-site roads combined with local traffic shall also comply with the relevant requirements for local highways.

3.1.4 On-site roads may be divided into on-site major roads and on-site minor roads according to their task, function, transport volume and other conditions.

3.2.1 On-site major roads shall be planned in an overall manner, arranged and reasonably connected according to the general construction layout and the construction scheme. According to their function, on-site major roads may be divided into material source haul roads, haul roads for spoil disposal areas and temporary stockpile areas, dam access roads, powerhouse access roads, connecting roads for production and living areas, and connecting roads for other main structures and main construction work areas, etc.

3.2.2 Material source haul roads shall be reasonably arranged according to the natural conditions, the material source planning, the excavation method and the transport mode, taking into account the access requirements of the material source excavation roads.

3.2.3 Haul roads for spoil disposal areas and temporary stockpile areas shall be considered in an overall manner and reasonably arranged in combination with their location, capacity, recovery of usable material and later use requirements.

3.2.4 Dam access roads shall meet the transport requirements for dam construction and later operation management, and shall be planned in an overall manner considering the construction interference among work faces and the traffic needs. For concrete dams, the dam access roads should be combined with the concrete delivery lines so as to meet the requirements for concrete placement intensity and temperature control. For embankment dams built of local materials, the dam access roads shall take into account the connection requirements of the fill roads at each elevation of the dam body.

3.2.5 Powerhouse access roads shall meet the transport requirements for powerhouse construction and later operation management, and shall be reasonably arranged in overall consideration with the other major roads.

3.2.6 Connecting roads for production and living areas shall be reasonably arranged according to the location and function of the production and living areas, in overall consideration with the other major roads.

3.2.7 For river-crossing bridges of on-site major roads connecting the two banks in the headworks area, a bridge site with good topographic and geological conditions, small bridge scale and short transport route shall be selected according to the transport task and function. Permanent traffic bridges should be planned and located outside the spray zone of the power station flood discharge.

3.2.8 Where the terrain is steep and slope stability problems are prominent, a tunnel alignment scheme should be considered for on-site major roads.

3.3.1 On-site minor roads may be divided into construction roads for diversion works, foundation pit excavation roads, dam construction roads, material source excavation roads and other connecting roads.

3.3.2 Construction roads for diversion works shall be reasonably arranged according to the construction requirements of the diversion structures and connected with the on-site major roads.

3.3.3 Foundation pit excavation roads shall be planned in an overall manner and reasonably arranged according to the foundation pit excavation method and the muck removal requirements, in combination with the topographic and geological conditions and the layout of the upstream and downstream cofferdams.

3.3.4 Dam construction roads may adopt the dam slope type, the bank slope type, the combined type or other types, and shall be reasonably arranged in combination with the dam type and the dam material transport mode, connecting with the on-site major roads.

3.3.5 Material source excavation roads shall be planned in an overall manner and reasonably arranged in combination with the material source haul roads, the collection platforms, the excavation method, the terrain conditions, etc.

3.4.1 The annual transport volume and the traffic density of on-site major roads shall be determined by analysis section by section and period by period, according to the transport volume, transport intensity and transport equipment derived from the general construction layout and the overall construction schedule of the hydropower project.

3.4.2 On-site major roads may be divided into Class I, Class II and Class III roads according to the annual transport volume or the traffic density. The classification of on-site major roads shall comply with Table 3.4.2 (Classification of on-site major roads).

Table 3.4.2, annual transport volume (unit: ten thousand tonnes): more than 1200 for Class I roads; 250 to 1200 for Class II roads; less than 250 for Class III roads.

Table 3.4.2, traffic density (vehicles per hour in one direction): more than 85 for Class I roads; 25 to 85 for Class II roads; less than 25 for Class III roads.

Note to Table 3.4.2: where the road class determined by the annual transport volume differs from that determined by the traffic density, the higher class shall govern.

3.4.3 Different road classes may be adopted for different sections of the same road according to function, annual transport volume, vehicle types and other conditions, but the connections between them shall be coordinated and the transitions shall be smooth.

3.4.4 The design speed of roads shall comply with Table 3.4.4 (Design speed of roads, km/h).

Table 3.4.4, design speed: 40 km/h for Class I on-site major roads; 30 km/h for Class II; 20 km/h for Class III; 15 km/h or less for on-site minor roads.

Note 1 to Table 3.4.4: where topographic and geological conditions are favourable, on-site minor roads should be designed to the Class III standard for on-site major roads.

Note 2 to Table 3.4.4: the design speed may be reduced on sections of on-site major roads restricted by site conditions, but the reduced design speed shall not be lower than the design speed of the next lower class.

3.5.1 The classification of design vehicle widths for roads shall be determined according to Table 3.5.1 (Classification of design vehicle widths, m).

Table 3.5.1, overall vehicle width: 2.5 m for width class 1; 3.0 m for class 2; 3.5 m for class 3; 4.0 m for class 4; 4.5 m for class 5; 5.0 m for class 6.

3.5.2 Roads should adopt an integral subgrade, and the road clearance (Figure 3.5.2) shall comply with the following provisions.

3.5.2 item 1: the lateral width shall be 0.5 m for Class I roads and 0.25 m for Class II roads; the lateral width of Class III roads and on-site minor roads may be 0 m; the lateral width inside tunnels, L-left or L-right, shall not be less than 0.25 m.

3.5.2 item 2: the width of the maintenance walkway or sidewalk should not be less than 0.75 m.

3.5.2 item 3: the top corner width of the clearance shall not be less than 0.25 m and shall not be greater than the sum of the lateral width and the residual width.

3.5.2 item 4: the residual width shall not be less than 0.25 m.

3.5.2 item 5: the height of the maintenance walkway should not be less than 0.25 m.

Figure 3.5.2 (Road clearance) shows the clearance outline for (a) integral-type roads and (b) tunnels; the side height of the outline is dimensioned at 4.0 m in both cases, and in the tunnel case a 2.5 m height is dimensioned above the maintenance walkway.

Legend of Figure 3.5.2: W — carriageway width; L — lateral width; J or R — maintenance walkway or sidewalk width; E — top corner width of the clearance; H — clearance height; C — residual width; h — maintenance walkway height.

3.5.3 Where emergency parking strips, passing bays or sidewalks are provided, the road clearance shall include the width of the corresponding parts.

3.5.4 The clearance height of roads shall be determined as the maximum height of the vehicles in service, or the maximum height of the vehicles when loaded, plus a safety margin of 0.25 m to 0.50 m, and shall not be less than 4.50 m. On-site roads to be used by large construction machinery and heavy or oversize items shall meet the clearance requirements for driving along the road centre.

3.5.5 No component whatsoever shall intrude into the road clearance.

4 Route

4.1.1 The horizontal alignment of on-site roads should be composed of three elements: tangents, circular curves and transition curves (clothoids).

4.1.2 Circular curves shall be provided in the horizontal alignment regardless of the size of the deflection angle, and the minimum radius of circular curves shall comply with Table 4.1.2 (Minimum radius of circular curves).

Table 4.1.2, minimum radius of circular curves: 45 m for a design speed of 40 km/h; 25 m for 30 km/h; 15 m for 20 km/h; 12 m for 15 km/h or less.

Note to Table 4.1.2: where conditions are restricted, the minimum radius of circular curves of on-site minor roads may be determined by the minimum turning radius of the vehicles travelling during construction and operation.

4.1.3 Where the circular curve radius is smaller than the minimum radius of circular curves without superelevation, a transition curve should be provided to connect the circular curve with the tangent. The minimum radius of circular curves without superelevation shall comply with Table 4.1.3 (Minimum radius of circular curves without superelevation).

Table 4.1.3, minimum radius of circular curves without superelevation: 250 m for a design speed of 40 km/h; 150 m for 30 km/h; 100 m for 20 km/h.

Note 1 to Table 4.1.3: superelevation may be omitted on on-site minor roads.

Note 2 to Table 4.1.3: for circular curves without transition curves, where superelevation is required, a superelevation runoff section shall be provided.

4.1.4 The minimum length of transition curves shall be determined according to the road class and the design speed, and shall comply with Table 4.1.4. Transition curves may be omitted on Class III roads and on on-site minor roads.