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According to the requirements of Notice on printing and distributing the development and revision plan on engineering construction standards and codes in 2014 (JIANBIAO [2013] No.169) issued by the Ministry of Housing and Urban-Rural Development of the People's Republic of China, the drafting group has revised this standard through extensive investigation and study, careful drawing of experience from practices, and reference to relevant international and foreign advanced standards and on the basis of widely soliciting for opinions.
The main technical contents of this standard are general provisions, terms and symbols, basic requirements, loads and effects, steel tower and mast structure, reinforced concrete cylindrical tower, ground and foundation, and relevant annexes.
The main technical contents revised in this standard are as follows: in order to be in coordination with the contents of the new standards issued recently by the state, relevant design contents of wind power tower have been added, requirements for the design of joints of high-rising steel pipe structures supplemented, and the requirements of anti-fatigue design of high-strength bolt under alternating tension and pressure action and the design requirements of prestressed anchor bolt foundation and foundation of prestressed anchor rod in rock for the wind power tower are put forward.
The provisions printed in bold type in this standard are compulsory and must be enforced strictly.
The Ministry of Housing and Urban-Rural Development is in charge of the administration of this standard and the explanation of compulsory provisions; Tongji University is responsible for the explanation of specific technical contents. In case of any comment or suggestion during the process of implementing this standard, please send it to Tongji University (address: A703 Civil Engineering Bldg., No.1239 Siping Road, Shanghai, 200092).
Standard for design of high-rising structures
1 General provisions
1.0.1 This standard is developed with a view to achieving safety, applicability, advanced technology and reasonable economy, ensuring quality and protecting environment in the design of high-rising structures.
1.0.2 This standard is applicable to design for steel and reinforced concrete high-rising structures, including radio and television tower, observation tower, communication tower, navigation tower, transmission tower, petrochemical tower, atmospheric monitoring tower, chimney, exhaust tower, water tower, headstock, watchtower, wind power tower, etc.
1.0.3 The design of high-rise structures shall comprehensively consider the issues of fabrication, protection, transportation, site construction as well as environmental effects and maintenance after completion.
1.0.4 The design of high-rising structures shall meet those specified in both this standard and the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
2.1.1
high-rising structure
high and thin structure
2.1.2
steel tower
high-rising steel structure of self-supporting frame type
2.1.3
guyed steel mast
high-rising steel structure composed of column and guy
2.1.4
reinforced concrete cylindrical tower
self-supporting reinforced concrete high-rising structure with cylindrical cross section
2.1.5
prestressed anchor bolt
unbonded prestressed anchor bolt anchored in the foundation through anchor plate for connecting the superstructure
2.1.6
prestressed anchor rod in rock
prestressed anchor rod in rock consisting of free section and anchoring section
2.1.7
progressive collapse
initial local destruction which extends from member to member and eventually leads to the collapse of the whole structure or a part of the structure that does not correspond to the cause
2.2 Symbols
2.2.1 Actions and action effects
Af——the amplitude of horizontal dynamic displacement at the tower under the action of wind pressure frequent value;
b——the basic ice thickness;
N——the design value of cable tension;
q——the linear distribution of gravity of concrete tube;
qa——the ice load per unit area;
q1——the Ice load per unit length;
1/rc——the bending deformation curvature at the representative section of the concrete tube;
1/rdc——the seismic bending deformation curvature at the representative section of the concrete tube;
SA——the downwind wind load effect corresponding to the calculation of crosswind critical wind speed;
SL——the crosswind wind vibration effect;
Swk——the effect of the wind load standard value;
Δu′——the interlayer horizontal displacement difference of cable;
Ve——the sum of the vertical components of shear resistance on the sliding surface of soil mass;
vcr——the critical wind speed;
ω0——the basic wind pressure;
ω1——the standard value of wind load on insulator string;
ωk——the standard value of wind load acting on unit projected area at the height of z of the high-rising structure;
ω0,R——the wind pressure representative value corresponding to the return period of R;
ωx——the standard value of horizontal wind load perpendicular to the direction of conductor and ground wire;
γ——the ice unit weight.
2.2.2 Calculation indexes:
C——the corresponding limits for deformation and crack specified in the design of high-rising structures;
fw——the design value of the strength of steel wire rope or steel stranded wire;
fu——the lowest tensile strength of anchor bolts after heat treatment;
Rt——the characteristic value of anti-uplift bearing capacity of single anchor rod;
σcrt——the local stable critical stress of tube wall.
2.2.3 Geometric parameters:
A——the gross section area of members, the section area of the steel wire rope or steel stranded wire of the cable, the concrete tube section area, and the area of the foundation bottom;
A1——the calculated value of air pressure bearing area of insulator string;
d——the outer diameter or, in the case of ice, the calculated outer diameter of conductor or ground wire; the diameter of members with circular section, pull ropes, lacing cords and overhead lines; the outer diameter of the calculated section of concrete tube; the outer diameter of circular plate (ring) foundation slab; and the anchor rod diameter;
d0——the inner diameter of the petrochemical tower;
H——the total height of high-rising structure;
h——the spacing of cables and the height of ribbed plates;
H1——the resonance critical wind speed starting height;
hcr——the critical depth calculated by soil weight method;
ht——the foundation uplift depth;
l0——the calculated length of rod between elastic support points;
rc——the average radius of bottom section of tube;
rco——the section core distance (radius);
t——the thickness of connecting piece and the thickness of tube wall;
α0——the anti-uplift angle for soil mass weight calculation;
θ——the angle between the wind direction and the direction of the conductor or the ground wire, and the angle between the tower column and plumb line,°;
λ0——the equivalent slenderness ratio of rod between elastic support points;
Φ——the half-angle of compression zone of section.
2.2.4 Calculation coefficients and others:
A0——the converted section area of horizontal section of concrete tube;
B1——the coefficient of wind load increase in the case of icing;
B2——the coefficient of wind load increase with ice on the transmission tower members;
fR——the maximum rotational frequency of the wind wheel within the normal operating range;
fR,m——the passage frequency of m wind wheel blades;
f0, n——the n-th order natural frequency of the tower (in complete machine state);
f0,1——the first order natural frequency of the tower (in complete machine state);
g——the peak factor;
I10——the turbulence intensity at the height of 10m;
Re——the Reynolds number;
St——the Strouhal number;
α1——the correction coefficient of ice thickness related to member diameter;
α2——the height increment coefficient of ice thickness;
αt——the half-angle coefficient of tensile reinforcement;
βz——the wind vibration coefficient at the height of z and the wind vibration coefficient of transmission tower;
γ0——the importance coefficient of high-rising structure;
γR1——the anti-uplift stability coefficient of soil weight;
γR2——the anti-uplift stability coefficient of foundation weight;
ε1——the influence coefficient with pressure fluctuation, wind pressure height variation, etc. taken into account;
ε2——the influence coefficient with vibration mode and structural shape taken into account;
εq——the coefficient with the influence of pressure fluctuation, height variation and vibration mode taken into comprehensive consideration;
λj——the coefficient of resonance area;
μs——the wind load shape coefficient;
μsc——the shape coefficient of conductor or ground wire;
μsn——the shape coefficient component perpendicular to the cross beam;
μsp——the shape coefficient component parallel to the cross beam;
μz——the height variation coefficient of wind pressure at the height of z;
ξ——the fluctuation amplifying coefficient, and the stiffness reduction coefficient of latticed mast when the mast is assumed as bending rod piece for calculating;
φ——the wind-breaking coefficient;
ψ——the strain uniformity coefficient of steel bar between cracks under longitudinal tension, and the form coefficient of annular foundation slab;
ψwE——the coefficient of wind load combination value in seismic fundamental combination;
ωhs and ωhp——the characteristic coefficient of horizontal section of concrete tube;
ωv——the characteristic coefficient of vertical section of concrete tube.
3 Basic requirements
3.0.1 In this standard, the limit state design method based on probability theory shall be adopted, the reliability of structure member measured by reliability index, and design carried out using the partial coefficient design expression.
3.0.2 The design reference period adopted in this standard is 50 years.
3.0.3 The design service life of high-rising structures shall meet the following requirements:
1 The design service life of high-rising structures of great importance shall be 100 years.
2 The design service life of general high-rising structures shall be 50 years.
3 For the communication tower built on the existing building or structure, its design service life should be matched with the subsequent design service life of the existing structure.
4 The design service life of wind power tower should be matched with that of the power generation equipment.
5 For high-rising structures with other special requirements, the service life should be determined according to specific conditions.
3.0.4 The high-rising structures shall meet the following functional requirements within the specified design service life:
1 They are able to withstand various possible loads and actions in normal construction and use;
2 They have good working performance in normal use;
3 They have sufficient durability under normal maintenance;
4 In case of an accidental event, the structure is able to maintain the necessary overall stability and free from damage consequences that do not correspond to the cause so as to prevent the progressive collapse of the structure.
3.0.5 In the design of the high-rise structures, different safety grades shall be adopted according to the possible consequences of structural damage and the severity of harmfulness to human life, economic losses, social and environmental impacts, etc. The safety grade classification of high-rising structures shall meet those specified in Table 3.0.5 and the following requirements:
1 The safety grade of high-rise structures shall be adopted in accordance with the requirements of Table 3.0.5.
Foreword ii
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements
4 Loads and actions
4.1 Classification of loads and actions
4.2 Wind load
4.3 Ice load
4.4 Earthquake action
4.5 Thermal action
5 Steel tower and mast structure
5.1 General requirements
5.2 Calculation of internal forces for steel tower and mast structure
5.3 Deformation and stability of steel tower and mast structure
5.4 Cable
5.5 Members under axial tension and compression
5.6 Members under combined axial force and bending
5.7 Welding connections
5.8 Bolted connections
5.9 Flange connections
5.10 Detailing requirements
6 Reinforced concrete cylindrical tower
6.1 General requirements
6.2 Deformation of tower and internal force calculation of section
6.3 Calculation of bearing capacity
6.4 Calculation of crack
6.5 Detailing of cylindrical
7 Ground and foundation
7.1 General requirements
7.2 Calculation for ground
7.3 Foundation design
7.4 Anti-uplift and anti-sliding stability of foundation
Annex A Materials and connections
Annex B Stability coefficient of axial compressed steel members
Annex C Local stability calculation of monopole
Annex D Critical value of gusset plate’s size
Annex E Calculation of capacity for section with openings
Annex F Calculation of distance between the centroidal axis and the central axis of the section, and moment of the core of the section
Annex G Stress calculation of section of concrete tube with openings
Annex H Pressure calculation coefficient of the base zero stress zone for circle or ring foundation under eccentric load
Annex J Calculation of the anti-uplift stability for foundation and anchored plate
Explanation of wording in this standard
List of quoted standards