NB/T 10391-2020 English PDF
Basic dataStandard ID: NB/T 10391-2020 (NB/T10391-2020)Description (Translated English): (Design specification for hydraulic tunnel) Sector / Industry: Energy Industry Standard (Recommended) Classification of Chinese Standard: P59 Classification of International Standard: 27.140 Word Count Estimation: 153,178 Date of Issue: 2020-10-23 Date of Implementation: 2021-02-01 Older Standard (superseded by this standard): DL/T 5195-2004 Regulation (derived from): National Energy Administration Announcement No. 5 [2020] Issuing agency(ies): National Energy Administration NB/T 10391-2020: (Design specification for hydraulic tunnel)---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.(Design specification for hydraulic tunnel) ICS 27.140 P 59 Energy Industry Standards of the People's Republic of China P NB/T 10391-2020 Replace DL/T 5195-2004 Design code for hydraulic tunnels Code for Design of Hydraulic Tunnel 2020–10–23 Released 2021–02–01 Implementation Issued by the National Energy Administration NB 1 General1.0.1 In order to standardize the design of hydraulic tunnels to be safe, reliable, technologically advanced, and economically reasonable, this specification is formulated. 1.0.2 This code is applicable to the design of hydraulic tunnels for new construction, reconstruction and expansion of hydropower projects. 1.0.3 The level of hydraulic tunnels should be in accordance with the current national standards "Flood Control Standards" GB 50201 and "Hydropower Junctions Relevant regulations of DL 5180 in Engineering Classification and Design Safety Standard shall be implemented. 1.0.4 The design of hydraulic tunnels should make full use of the self-stability, bearing capacity and impermeability of the surrounding rock. 1.0.5 For pressurized hydraulic tunnels lined with steel plates, the structural design shall be in accordance with the current industry standard "Hydropower Station Pressure Relevant regulations of NB/T 35056 of "Code for Design of Power Steel Pipe" shall be implemented. 1.0.6 The design of the hydraulic tunnel shall meet the requirements of the overall project planning and environmental protection. 1.0.7 The design of hydraulic tunnels shall not only conform to this code, but shall also conform to the current relevant national standards.3 Basic regulations3.0.1 The design of hydraulic tunnel shall be based on the layout of the hub, the function of the tunnel and the requirements of different design stages, and the water collection shall be Culture, sediment, kinetic energy economy, topography, geology, earthquake, ecological environment, soil and water conservation, construction conditions, gold Information on structures, mechanical and electrical equipment, building materials, and operating methods. 3.0.2 The geological survey work at the entrance and exit of the tunnel and along the route shall be based on the complexity of the topography and geological conditions, The level of the tunnel and the different design stages shall be in accordance with the current national standard "Specifications for Geological Survey of Hydropower Engineering" The relevant regulations of GB 50287 shall be implemented. Representatives should be selected on-site for level 1 high-pressure tunnels and high-pressure concrete forks In-situ stress test, hydraulic fracturing and other tests are carried out in the natural section. 3.0.3 The following basic geological data should be collected in the preliminary design stage of hydraulic tunnels. 1 Surrounding rock characteristics, geological structure and in-situ stress along the tunnel. 2 Karst and hydrogeology along the cave line. 3 The stability of the entrance and exit of the tunnel and related slopes. 4 Karst caves, water bursts, rock bursts, high ground temperature, harmful gases and radioactive substances that affect the safety of the tunnel Geological phenomenon. 3.0.4 The excavation of hydraulic tunnels should be based on actual conditions and timely geological cataloging, collecting and checking geological data, And conduct geological forecasts for construction. For tunnel sections with complex geological conditions, pilot tunnels, advance drilling, and Advance geophysical exploration and other methods to prove geological conditions. 3.0.5 The classification of surrounding rocks of hydraulic tunnels shall comply with the current national standard "Code for Geological Survey of Hydropower Engineering" The relevant regulations of GB 50287. 3.0.6 The material parameters of sprayed concrete, anchor rods, concrete, steel bars and other materials used in the design of hydraulic tunnels shall comply with The current national standard "Technical Code for Geotechnical Anchor and Shotcrete Support Engineering" GB 50086 and "Hydraulic Engineering Relevant regulations in "Code for Design of Concrete Structures" DL/T 5057. 3.0.7 Stone gathering pits should be set up in the long-distance water transmission power tunnel.4 Tunnel layout4.1 Hole line selection 4.1.1 The tunnel line should be based on the use and characteristics of the tunnel, comprehensively considering the topography, geology, buried depth, ecological environment, Various factors such as water and soil conservation, general layout of the hub, hydraulics, construction, operation, buildings along the route, etc. Technical economy is more selected. 4.1.2 On the premise of meeting the requirements of the general layout of the hub, the tunnel line should be selected where the geological structure is simple and the rock mass is intact and stable. Areas with favorable hydrogeological conditions and convenient construction and transportation shall meet the following requirements. 1 There should be a large included angle between the hole line and the strata layer, the main structural fracture surface and the strike of the weak zone. The included angle should not be less than 30º; for thin rock formations with high dip angle with loose interlayer bonding, the included angle should not be less than 45º. folder Engineering measures should be taken when the angle is less than the specified value. 2 For tunnels in high in-situ stress areas, the influence of in-situ stress on the stability of surrounding rock should be considered. The tunnel line and the maximum level The directions of ground stress should be consistent or intersect at a small angle. 3 The angle between the outlet axis of the spillway tunnel, the emptying tunnel, and the sand flushing tunnel, and the middle line of the downstream channel should be Determined according to factors such as topographic and geological conditions and hydraulic conditions at the outlet of the spillway. 4.1.3 Tunnels with a small buried depth or close to the surface can adopt the option of increasing the buried depth, open channels or pipelines, and the options should be accessible. Selected through technical and economic comparison. 4.1.4 The minimum rock mass coverage thickness of the tunnel shall be based on topographical conditions, geological conditions, the anti-lifting capacity of the rock mass, Factors such as anti-seepage characteristics, water pressure in the tunnel and support type are analyzed and determined, and the following requirements should be met. 1 The minimum cover thickness of the rock mass of a pressure tunnel (Figure 4.1.4) should be determined based on the hydrostatic pressure in the tunnel being less than or equal to the top of the tunnel. The requirements for the gravity of the upper rock are determined, and it should be calculated according to the following formula. cos sw RM h F (4.1.4) In the formula. CRM--the minimum covering thickness of the rock mass that does not include full and strong weathering thickness (m); hs--The hydrostatic pressure head in the cave (m); w --weight of water (N/mm 3); R --Rock weight (N/mm 3); F--The empirical coefficient should be 1.30～1.50, and the higher value should be taken when the geological conditions are poor. α--The slope angle of river valley bank (°), when α >60°, α is taken as 60°; 2 The minimum cover thickness of the rock mass of the pressure tunnel shall ensure that the surrounding rock does not produce seepage instability, and the surrounding rock sees hydraulic power The gradient should meet the requirements of osmotic stability. Important projects or tunnels with extremely high water heads should be combined with high-pressure permeability tests. Conduct special research on the permeability stability of surrounding rock under high water pressure. 3 High-pressure tunnels and bifurcated tunnels should still meet the requirement that the hydrostatic pressure in the tunnel is less than the minimum ground stress of the surrounding rock. 4 For tunnels under pressure that cannot meet the requirements of paragraphs 1 to 3 of this article, reasonable construction procedures and engineering shall be adopted. Measures to ensure safety during construction and operation. 5 Under the conditions of ensuring safety during construction and operation, the minimum covering thickness of unpressured tunnels may not be specified degree. 4.1.5 Two or more tunnels may be used for tunnels with large overflow and engineering geological conditions that are not conducive to the excavation of large cross-sections. The layout plan should meet the following requirements. 1 The layout plan should be based on hydraulic and rock mass stress conditions, the layout, construction and operation of the head and tail buildings. Comprehensive analysis and determination of factors such as operating conditions, the possibility of putting into operation in stages, project cost and construction period. 2 The parallel arrangement plan of multiple spillway tunnels should be based on the inlet water flow conditions and excavation coordination, outlets of adjacent tunnels. The layout of the buildings and the impact resistance of the downstream riverbed are comprehensively analyzed and determined, and coordinated with the auxiliary buildings of the tunnel. Tune. 4.1.6 The thickness of the rock mass between adjacent or intersecting tunnels shall be based on the layout needs, topographic and geological conditions, Stress and deformation of surrounding rock, hydraulic fracturing and seepage stability of rock mass, shape and size of tunnel section, construction Comprehensive analysis and determination of factors such as construction methods, operation and maintenance conditions. The thickness of the rock mass should not be less than that of the smaller hole diameter 2 times the excavation diameter (hole width), and it should be ensured that there is no seepage instability and hydraulic fracturing during the operation period. 4.1.7 The tunnel with the tunnel line passing through the dam foundation, dam abutment or other building foundations shall meet the following requirements. 1 The thickness of the rock mass between the tunnel and the above-mentioned buildings shall meet the requirements of structure and anti-seepage. 2 Pressure tunnels should be analyzed in relation to the arrangement of dam curtains and powerhouse curtains, and should be based on surrounding rock conditions, The conditions of adjacent buildings shall determine the anti-seepage and drainage measures. 4.1.8 A steel lining section should be installed between the high-pressure tunnel and the underground powerhouse. The length of the steel lining section should not be less than the maximum static head. 0.25 times. 4.1.9 The tunnel crossing plan shall be based on topography, geology, hydrology, construction and seismic conditions, and pass through the ditch and span. The ditch plan is technically and economically determined, and the cross-ditch plan should consider the impact of floods and debris flows in the valley. 4.1.10 The plane turning section of the hydraulic tunnel shall meet the following requirements. 1 The turning radius of low-velocity non-pressure tunnels should not be less than 5 times the diameter of the tunnel (hole width), and the turning angle should not be greater than 60°. A straight section should be set at the beginning and end of the curve, and the length should not be less than 5 times the hole diameter (hole width). Low flow rate pressure tunnel The requirements of the hole can be appropriately reduced, but the turning radius should not be less than 3 times the hole diameter (hole width). 2 The line of the high-velocity pressureless tunnel should be arranged as a straight line on the plane. 3 The curve parameters of high-velocity pressure tunnels should be determined through hydraulic model tests. 4 For tunnels that use roadheaders and tracked transport of slag, the turning radius and corners should meet the requirements of roadheaders and tracked tunnels. Transportation requirements. 4.1.11 The vertical curve type and radius of high-velocity tunnels should be determined through hydraulic model tests. Low flow rate non-pressure tunnel The radius of the vertical curve of the tunnel should not be less than 5 times the hole diameter (cavity width); the radius of the vertical curve of the tunnel with low flow velocity and pressure should not be less than 3 times the hole diameter (hole width). The connection arrangement between the vertical curves should be combined with hydraulic conditions, construction methods and other factors Comprehensively determine. 4.1.12 The longitudinal slope of the tunnel shall be in accordance with the operation requirements, hydraulic conditions, upstream and downstream connection, construction and maintenance rules. It is not suitable to set up a reverse slope. 4.1.13 The long tunnel constructed by the drill and blast method shall be provided with construction support tunnels. The number and length of branch holes should be based on the The requirements of shape, geological conditions, external traffic conditions, construction conditions, engineering quantities and construction period, etc. shall be adopted through technical and economic Confirmed after comparison. 4.2 Import and export layout 4.2.1 The layout of the entrance and exit of the tunnel should be based on the functional requirements, the general layout of the hub, topographic and geological conditions, and hydraulic conditions. Factors such as parts, anti-silt, anti-fouling and anti-fouling requirements are determined. 4.2.2 The entrance of the cave should be selected on the bank slope with simple geological structure, shallow overburden, rock weathering and unloading, and should be avoided. Bad geological areas such as faults, collapses, landslides and mudslides. 4.2.3 The inlet and outlet slopes should be reinforced, waterproofed and drained according to the results of the slope stability analysis, and should be avoided. Excavation of high slopes. 4.2.4 The inlet layout of the power tunnel shall comply with the current industry standard "Specifications for the Design of Intakes of Hydropower Stations" The relevant regulations of DL/T 5398.The entrance layout of other hydraulic tunnels can be open or deep, and the entrance layout The following requirements should be met. 1 The water boundary of the open inlet should be smooth and smooth. The design requirements of the control weir (sluice) should conform to the current The relevant provisions of the industry standard "Specifications for Spillway Design" DL/T 5166. 2 The inlet of the deep short pipe should include the inlet horn section, the door groove section and the pressure slope section. The pressure slope section in front of the working gate should be For the contraction type, the pressure distribution in the segment should decrease smoothly along the course to avoid cavitation. 3 The inlet of the deep long pipe should adopt the elliptic curve type with the top and both sides contracting in three directions. 4 The inlet flow method should avoid unfavorable vortex and backflow before the inlet. The terrain or layout, body shape is more complicated The import should be verified by hydraulic model test. 4.2.5 The layout of the entrance of the water conveyance tunnel of the pumped storage power station shall be adapted to the requirements of two-way flow of water. Model test confirmed. 4.2.6 The outlet of the pressure relief tunnel should be well connected with the downstream, and the shape of the outlet tunnel should meet the following requirements. 1 The shape of the exit tunnel section should be determined according to the hydraulic conditions, the type and layout of the working gate, and the way of opening the door. 2 The cross-sectional area of the exit should be 85% to 90% of the cross-sectional area of the cave body. There are many body changes along the way, inside the cave When the water flow conditions are poor, the shrinkage rate should be 80%-85%. Important hydraulic tunnels should undergo hydraulic model tests Test. 4.2.7 The design of supplement and exhaust facilities for hydraulic tunnels shall meet the following requirements. 1 Pressure tunnels should be provided with vent holes at the inlet or outlet, and the area of the vent holes can be in accordance with the current industry standards Calculation of relevant formulas in "Code for Design of Water Inlet of Hydropower Station" DL/T 5398. 2 High-velocity pressureless tunnels with aeration facilities should be set up in phases with the outside atmosphere according to the water flow velocity. The location and number of the independent air supplement tunnels should be determined through hydraulic model tests. Underground working lock room It is advisable to set up an independent air supplement hole. The average wind speed of air supplement should be less than 40 m/s, and the maximum wind speed should be less than 60 m/s. 4.2.8 The outlet layout of the discharge tunnel shall ensure that the discharge flow does not affect the safety and normality of other buildings and facilities run. 4.3 Multi-purpose tunnel 4.3.1 The layout plan of the tunnel shall be based on the use, operation and construction conditions of the tunnel, and study the combination of temporary and permanent The feasibility and economy of combining multiple uses with one hole. 4.3.2 The design of the combined temporary and permanent tunnel shall meet the requirements of temporary water passing and permanent operation. 4.3.3 The design of the diversion tunnel should be studied to use all or part of the tunnel section as a spillway, emptying tunnel, and sand drainage tunnel. The possibility of permanent hydraulic tunnels such as tailrace tunnels for power generation. 4.3.4 The reconstruction of the flood discharge tunnel can adopt the forms of energy dissipation in the tunnel, such as swirling flow, cave plug, orifice plate, etc., which should be combined with the scale of discharge, The water head and the anti-seepage arrangement on both sides of the dam body, the topography and geological conditions of the river bed and both sides, the water depth and water level changes of the downstream channel The width and other factors shall be comprehensively studied and determined, and shall be verified through hydraulic model tests. 5 Cross-sectional shape and size 5.1 General provisions 5.1.1 The cross-sectional shape and size of the tunnel body should be based on the use of the tunnel, hydraulic conditions, engineering geology and hydrology. Geology, ground stress, surrounding rock reinforcement methods, construction methods and other factors are determined through technical and economic analysis. 5.1.2 The flow pattern in the tunnel shall meet the following requirements. 1 Pressure tunnels should not have alternating flow patterns of open and full flow. Under the most unfavorable operating conditions, the top of the tunnel The minimum pressure head should not be less than 2.0 m. 2 High-velocity discharge tunnels should not have alternating flow patterns of open and full flow. Sluice tunnels with low flow velocity can be used for flood check In water conditions, there is an alternating flow pattern of open and full flow. 3 The tailrace tunnel and diversion tunnel have been researched and demonstrated to allow alternating flow pattern......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of NB/T 10391-2020_English be delivered?Answer: Upon your order, we will start to translate NB/T 10391-2020_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of NB/T 10391-2020_English with my colleagues?Answer: Yes. The purchased PDF of NB/T 10391-2020_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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