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(Code for design of RCC arch dam)
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NB/T 10335-2019
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Standard similar to NB/T 10335-2019 NB/T 10077 NB/T 10351 NB/T 10334 Basic data | Standard ID | NB/T 10335-2019 (NB/T10335-2019) | | Description (Translated English) | (Code for design of RCC arch dam) | | Sector / Industry | Energy Industry Standard (Recommended) | | Word Count Estimation | 120,146 | | Date of Issue | 2019-12-30 | | Date of Implementation | 2020-07-01 | | Issuing agency(ies) | National Energy Administration | NB/T 10335-2019: (Code for design of RCC arch dam)---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.
(Code for design of RCC arch dam)
ICS 27.140
P 59 NB
Energy Industry Standards of the People's Republic of China
Design code for roller compacted concrete arch dam
Code for Design of Roller-Compacted Concrete Arch Dams
2019-12-30 released
2020-07-01 implementation
Issued by the National Energy Administration
11 General
1.0.1 In order to standardize the design of roller compacted concrete arch dams, to ensure the design quality, and to ensure that the design is safe, reliable, economical and reasonable.
This specification is formulated for the requirements of advanced technology, environmental friendliness, and resource conservation.
1.0.2 This code is applicable to the design of roller compacted concrete arch dams on the rock foundations of newly built, rebuilt and expanded hydropower projects.
1.0.3 The design of roller compacted concrete arch dams shall not only conform to this code, but shall also conform to the current relevant national standards.
22 Terminology
2.0.1 Roller-compacted concrete (RCC)
Pave the dry hard concrete mixture in layers and vibrate to compact the concrete.
2.0.2 Grout-enriched RCC
In the roller compacted concrete mixture, a certain proportion of mortar is mixed and vibrated to compact concrete.
2.0.3 RCC arch dam
An arch dam made of roller compacted concrete.
2.0.4 transverse joint
In a certain cross-section or similar cross-section in the dam body, an inductive structure is laid or casted in sections to form a through joint surface to make the fracture
A structure that has no crack resistance on the surface, thereby releasing the temperature stress during the construction period.
2.0.5 Inducing joint
In a certain cross-section or similar cross-section in the dam body, the induced structure is arranged to form an incompletely through joint surface, so that the cross-section resists
A structure in which the cracking ability is reduced, thereby inducing cracking and releasing the temperature stress during the construction period.
2.0.6 roller compacted concrete lift joint
The bonding surface of the upper and lower layers of RCC.
2.0.7 Mineral admixture
Active or inactive mineral materials mixed into concrete to improve the performance of concrete and reduce the amount of cement.
2.0.8 layer placement duration
The duration from the completion of the rolling of the lower layer of concrete to the completion of the rolling of the upper layer of concrete.
33 Basic rules
3.0.1 RCC arch dams can be divided into low dams, medium dams and high dams according to their dam height. The dam height is less than 30m as low dams.
The middle dam is 30m～70m high, and the high dam is above 70m.
3.0.2 RCC arch dams can be divided into thin arch dams, medium-thick arch dams and thick arch dams according to their thickness-to-height ratio. The thickness-to-height ratio is less than 0.20
It is a thin arch dam, 0.20～0.35 is a medium-thick arch dam, and greater than 0.35 is a thick arch dam or a gravity arch dam.
3.0.3 The design of RCC arch dam should collect and master the meteorology, hydrology, sediment, topography, geology, and geology of the area where the dam is built.
Basic information such as earthquakes, building materials, ecological environment, etc., to study the construction conditions to ensure the safety, economy and applicability of the project.
3.0.4 The design of RCC arch dam shall meet the following requirements.
1 Optimizing the structural layout of the arch dam, choosing the shape and basic dimensions of the arch dam reasonably, meeting safety and functional requirements, and benefiting
Rapid construction of roller compacted concrete.
2 Optimizing dam concrete raw materials, reasonably determining the concrete strength grade and related design indicators, and reasonably determining the dam
Body concrete partition.
3 Reasonably carry out dam body splitting and temperature control anti-cracking design to improve the anti-cracking performance of roller compacted concrete.
4 Put forward the construction requirements for dam pouring and joint grouting during the implementation process to ensure the safety of the dam structure.
3.0.5 The hydraulic design and foundation treatment design content of the RCC arch dam shall conform to the current industry standard "Concrete
Arch Dam Design Code" DL/T 5346.
3.0.6 The design of roller compacted concrete arch dams with a dam height greater than 150m or particularly important, while complying with this code, shall also
Conduct special research on special issues.
44 Layout of RCC Arch Dam
4.1 General rules
4.1.1 The roller compacted concrete arch dam should be arranged at the rock foundation dam site with narrow river valley and good geological conditions, and with good roller compaction.
Sources of concrete raw materials and construction conditions.
4.1.2 The axis selection of RCC arch dam shall meet the following requirements.
1 Dam abutments on both banks should have a relatively complete resistance rock mass to ensure sufficient stability of the arch abutment.
2 There should be good flood discharge and energy dissipation conditions.
3 The formation of high excavation slopes should be avoided.
4.1.3 The layout of the RCC arch dam pivot should be based on the topography, geology, and hydrology of the dam site on the basis of meeting the functional tasks.
It will be determined after technical and economic comparison of natural conditions.
4.1.4 The layout of the RCC arch dam and the discharge structure of the dam body, the diversion and power generation structure and other structures shall be based on
According to factors such as the importance, type, construction conditions and operation management of the building, make overall arrangements.
4.1.5 The structural layout of the RCC arch dam body should be rapid construction of RCC and expanded use of RCC
The scope creates the conditions.
4.2 Body shape design
4.2.1 The shape of the RCC arch dam shall comprehensively consider the shape of the valley at the dam site, geological conditions, and the layout and structure of the dam body.
The influence of factors such as structure, dam body stress, arch abutment stability, and construction conditions are determined through comparison and selection.
4.2.2 The shape design of the RCC arch dam shall meet the following requirements.
1 The dam body stress should meet the stress control standards and the requirements of the dam foundation bearing capacity, and the distribution should be reasonable.
2 The maximum center angle of the arch ring should be between 75° and 110°.
3 The overhang degree of the cantilever beam section should not be greater than 0.25.
4 The influence of the structural layout of the dam discharge structure on the integrity of the arch dam should be considered.
5 Under the premise of meeting the stress control standards, it is advisable to increase the angle between the arch dam thrust and the used rock surface contour. arch
The angle between the tangent of the inner arc at the end and the contour line of the used rock surface should not be less than 30°.
6 It should have good adaptability to rapid construction and meet the requirements of roller compacted concrete construction technology and construction equipment operation.
4.2.3 The shape design of the RCC high arch dam shall be carried out according to the elastic modulus of the dam body and the comprehensive deformation model of the foundation.
Sensitivity analysis of the amount and temperature effect.
54.2.4 If one of the following situations exists on both banks or one bank of the RCC arch dam site, gravity piers and thrust piers can be installed.
1 The upper terrain is open.
2 Poor bedrock is not suitable for arch dam foundation.
3 Not satisfying the stability of the arch.
4.2.5 When there are local geological defects in the foundation of the RCC arch dam, pedestals can be set to meet the stress and stability requirements.
4.2.6 When the shape of the valley of the dam site or the symmetry of the geological conditions is poor, measures should be taken to improve the stress and stability conditions of the dam body.
4.3 Dam body buildings
4.3.1 The discharge structure of the roller compacted concrete arch dam body should preferentially adopt the overflow surface hole. The dam body is set with middle hole, deep hole or bottom
When making holes, it is advisable to reduce the number of layers and the number of holes in the dam body.
4.3.2 When discharging, diversion, water intake and other orifices are arranged on the RCC arch dam body, the orifice size, number, position and
The shape is determined, and the functional and safety requirements, the stress of the dam structure and the coordination relationship with other buildings should be considered comprehensively
And other factors.
4.3.3 The layout of the traffic, grouting and monitoring corridors in the RCC arch dam should be simple and reasonable to reduce the stress on the dam body
The impact of the impact and the construction interference of RCC, and is conducive to the safety of the flood during the construction period.
4.3.4 When a behind-dam-type powerhouse is adopted, the layout of the pressure pipeline and powerhouse shall be combined with the stress status of the dam body, water discharge and energy dissipation.
Building layout, construction and operating conditions, etc., are determined after technical and economic comparison.
65 Roller Compacted Concrete Dam
5.1 General provisions
5.1.1 The cement, aggregates, water, admixtures, admixtures, etc. used in RCC should meet the current national standards and
Regulations of industry standards.
5.1.2 Medium-heat Portland cement or ordinary Portland cement with low calorific value should be selected for RCC, and according to the project
The special needs of cement put forward special requirements for the chemical composition, mineral composition, heat of hydration and fineness of cement.
5.1.3 Active admixtures such as fly ash, granulated blast furnace slag powder and pozzolan should be used as the admixture of RCC.
5.1.4 The sand and gravel source of RCC should be combined with the construction material distribution and storage conditions in the project area, the quality of the source, and the mining
Conditions, mix ratio research, construction quality control and other factors are determined after technical and economic comparison.
5.1.5 The aggregate used for the concrete of the dam body and the auxiliary structure shall be tested for alkali activity, and the alkali-carbonate reaction shall not be used.
Active aggregates. Aggregates with alkali-silicate reaction activity should take inhibitory measures and be proven to meet the requirements before they can be used.
use.
5.1.6 Roller compacted concrete should be mixed with retarded water to reduce water consumption and meet the requirements of millability, retardation and durability.
Additives such as air-entraining agents.
5.1.7 RCC should meet the performance requirements of dam strength, impermeability, durability and low heat.
5.1.8 When the environmental water is corrosive, suppression measures such as optimizing cement, admixtures, admixtures and mixing ratios should be taken.
And verified by experiment.
5.2 Strength grade of RCC
5.2.1 The strength grade of roller compacted concrete of the dam body is expressed by the standard value of the compressive strength of the concrete cube, and the symbol is "C age
Standard value of compressive strength of cube (MPa)". Standard value of compressive strength of roller compacted concrete cube shall be made by standard methods.
The side length of the guard is a 150mm cube test piece, and the 80% guarantee rate is measured by standard test methods at the design age.
The compressive strength is determined. The design age is generally 90d, and 180d can also be used after verification.
5.2.2 The strength grade of RCC of the dam body shall not be lower than C9015.
5.3 Physical and mechanical indexes of RCC
5.3.1 When the RCC of the dam body uses the compressive strength of the non-design age, the compressive strength of the RCC of the age increases
The rate should be determined through experiments, and the value of similar projects can be referred to when there is no test data for the middle and low dams.
86 Stress Stability Analysis of Arch Dam
6.0.1 The stress of the dam body and the stability of the arch abutment shall be calculated for the RCC arch dam, and appropriate engineering measures shall be taken when necessary.
Ensure the safety of the arch dam.
6.0.2 RCC arch dam stress analysis, arch abutment stability analysis, overall stability analysis and geomechanical model test application
It complies with the current industry standard "Specification for Design of Concrete Arch Dams" DL/T 5346.
6.0.3 The stress and stability analysis of the RCC arch dam under earthquake action shall comply with the current industry standard "Water Power Engineering
"Code for Seismic Design of Industrial Buildings" NB 35047.
6.0.4 The stress analysis of RCC arch dams shall adopt the arch-beam load sharing method. High dams or dams with larger holes and larger attachments
In the case of structures, finite element analysis should also be carried out.
6.0.5 The stress calculation of RCC arch dam shall consider the structure of the dam body, the load acting on the dam body, the dam foundation, and the geology of the dam foundation.
Defects, construction process and water storage process, etc., to ensure that the arch dam stress meets the requirements under various operating conditions.
Good adaptability.
6.0.6 The sealing temperature of the RCC arch dam shall be based on the stable temperature field of the dam body, temperature conditions, temperature control conditions, and construction
The construction period and the dam stress calculation during the operation period are comprehensively determined. When the dam body is not equipped with transverse joints, induced joints or the spacing of the joints is too large,
The highest temperature field before the design age of the concrete in each pouring area should be used as the arch sealing temperature, or in the dam stress calculation
Include the temperature residual stress during the construction period.
6.0.7 For high RCC dams or RCC arch dams with complex geological conditions, the arch dam-foundation integral non-linear
Finite element analysis, and geomechanical model tests should be carried out when necessary.
7.2.2 The RCC of the dam body can adopt different strength grades according to the elevation or position.
The difference in degree level should not exceed one level. The difference between the strength grades of adjacent partitions of RCC and normal concrete should not exceed
Two levels.
7.2.3 The zone width of RCC of different grades or different gradations should be based on the force requirements, durability requirements, and durability requirements of the dam body.
The structural requirements and construction conditions are determined, and it should not be less than 3m.
7.2.4 The upstream and downstream surfaces of the RCC arch dam should be equipped with 0.5m~1.0m thick deformed concrete.
7.2.5 The foundation of the river bed should be made of normal concrete, deformed concrete or directly laid sand according to the flatness of the foundation.
After the slurry is leveled, the roller compacted concrete construction is carried out. The thickness of foundation concrete can be adjusted according to the undulation difference of foundation excavation, temperature control and dam
The foundation consolidation grouting requirements are determined.
7.2.6 Distorted concrete should be used for the dam foundations of the slopes on both sides of the bank, and the thickness should be 1.0m.
7.3 Joints of the dam body
7.3.1 The joints of RCC arch dams may adopt transverse joints, induced joints or other joints.
7.3.2 The roller compacted concrete arch dam shall be based on the temperature control and crack prevention requirements, the geological conditions of the dam foundation, the layout of the dam body structure, and the construction
Conditions, etc., set horizontal seams or induced seams, not longitudinal seams.
7.3.3 The transverse joints should be provided with a keyway, and a water stop and grouting system should be arranged. The keyway can be trapezoidal, arc-shaped or spherical.
7.3.4 Water stop and grouting system should be arranged in the induction joint. The area of the induced joint should not be less than 25% of the total cross-sectional area.
7.3.5 The transverse joints and induced joints can be set as radial or close to radial vertical joints and radial twisted joints. The joint surface near the dam foundation and
The included angle of the dam foundation surface should not be less than 60°.
7.3.6 The spacing of induction joints and transverse joints should be determined according to temperature control and crack prevention calculations or analogous projects, and should be 30m~50m.
In determining the distance, full consideration should be given to factors such as the rock soft and hard conditions of the arch dam foundation, inhomogeneity, and steep bank slopes.
7.3.7 The contact joint surface between the roller compacted concrete of the dam body and the concrete around the discharge orifice of the dam body for non-synchronous pouring shall be provided with a key
Grouting system can be arranged for grooves and seam steel bars according to needs.
7.4 Joint grouting
7.4.1 Joint grouting shall be carried out for the transverse joints and induced joints of the dam body. After the grout stones reach the design strength, the dam body can be long-term
Retaining water by force.
7.4.2 During the construction period, the dam body is temporarily blocked by the flood or the reservoir is impounded in stages. When part of the arch ring of the dam body has not been completed, the arch grouting has not been completed.
Yes, the safety of the arch dam should be analyzed and demonstrated.
7.4.3 The joint grouting system should be set as a grouting system that can be grouted repeatedly.
7.4.4 Joint grouting shall meet the following requirements.
1 The temperature of the dam concrete in the grouting area should be lowered to the designed value.
2 The thickness of the upper cover of the grouting area should not be less than 6m.
3 The difference between the concrete temperature between the cover layer and the grouting zone should not be greater than 3°C.
4 The age of the dam concrete on both sides of the joint should not be less than 90d, and the age of the cover layer concrete should not be less than 28d.
5 Cement can be used as grouting material if the seam opening is greater than 0.5mm, and the seam opening is not greater than 0.5mm.
Use ultra-fine cement or chemical materials as grouting materials.
7.4.5 The joint grouting pressure should be 0.3MPa～0.6MPa, and the top layer grouting pressure can be appropriately reduced.
7.4.6 The area of each irrigation area of transverse joints and induction joints should be 300m2～450m2, and the height should not be greater than 15m.
7.5 Corridor and traffic in the dam
7.5.1 Grouting and drainage corridors, monitoring corridors and traffic corridors can be set up in the dam as required, and the layout of the corridor structure
It should be determined according to the functions of each corridor and the influence of the corridor on the layout and structure of the dam.
7.5.2 The layout of the gallery should avoid the tensile stress area of the dam body. The net distance between the corridor and other holes should satisfy the stress and local structure of the dam body.
Institutional requirements. The distance between the upstream wall of the longitudinal corridor and the upstream dam surface should not be less than 0.05 to 0.10 times the acting head of the dam surface.
And not less than 3m.
7.5.3 The structural layout design of the corridor within the dam should consider factors such as the traffic connection and ventilation conditions outside the dam, and the corridor should be equipped with
Install adequate lighting facilities. Various equipment and circuits should be well insulated and easy to repair.
7.5.4 When setting up multi-level corridors, the corridors on each level in the dam should adopt traffic facilities such as traffic bridges, stairs, elevators, and shafts behind the dam.
It is convenient for safe passage during construction and operation period.
7.5.5 When the floor of the drainage gallery is below the highest water level in the downstream, a drainage system should be provided, and when it is above the highest water level in the downstream
Gravity drainage can be used.
7.5.6 The inlets and outlets of the gallery inside the dam leading to the outside of the dam, where it is possible to inject outside water, measures should be taken to prevent outside water intrusion.
7.5.7 The corridors, drainage equipment and traffic facilities in the dam shall meet the requirements of fire safety.
7.5.8 The structural layout design of auxiliary buildings such as shaft shafts and elevator shafts of the dam shall consider the influence of the deformation of the dam.
7.6 Dam body water stop and drainage
7.6.1 The joints of the dam body and the contact surface of the steep slope foundation on both banks shall be provided with a water stop on the side of the water facing surface with a higher water head.
Two or more water-stops should be installed, and the distance between the water-stops should be 0.3m~0.5m. The water-stop material and its structure type should be in accordance with
The current industry standard "Technical Standards for Plastic Caulking and Sealing Materials for Hydraulic Buildings" DL/T 949 and "Hydraulic Buildings
Implementation of the provisions of DL/T 5215 "Hose Technical Specifi...
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