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According to the Shanghai Engineering Construction Standard Design and Development Plan in 2010 (the second batch) issued based on HUJIANJIAO [2010] No.731, the revision group composed of Tongji University and other units has comprehensively revised DGJ08-9-2003 Code for seismic design of buildings as the Shanghai Engineering Construction Standard. During the revision, this code was developed based on the objectives of advanced technology, economic rationality, convenience for implementation and coordination with other standards, by making reference to the national standard GB 50011-2010 Code for seismic design of buildings.
This code consists of 14 clauses and 11 annexes. With respect to GB 50011-2010 Code for seismic design of buildings, this code has the following main differences: (1) Different seismic design response spectrum and seismic ground motion parameters, and different characteristic period (frequent earthquakes and rare earthquakes), period range applicable to the descent section of the design response spectrum, and maximum of acceleration time history used in the time history analysis of rare earthquakes; (2) 14 seismic wave acceleration time histories applicable to time history analysis are added in the annex; (3) The performance-based seismic design method is supplemented and modified; the division basis of seismic performance levels and performance objectives is defined; the maximum limits of inter-story displacement angle of various structures are provided corresponding to seismic performance levels; (4) The requirement of strength grade of steel bar is improved for the popularization and application of high-strength steel bar; (5) The judgment method of irregular structure plane is different; for convex structure, double control indicators (protruding length and width) are used as the judgment basis, and the explanation of provisions is more detailed according to the actual engineering situation in Shanghai; (6) The provisions of site, subgrade and foundation are different, which are basically consistent with the current Shanghai Engineering Construction Standard DGJ08-11-2010 Foundation design code, and the liquefaction judgment equation based on standard penetration test is consistent with Shanghai Engineering Construction Standard DGJ08-37-2012 Code for investigation of geotechnical engineering; (7) The checking indicators of structural seismic deformation is further detailed, and the limits of elastic inter-story displacement angles are added for structures such as RC wall, frame-shear wall and frame-supported story (the upper story of embedded end); (8) The limits of axial compression ratio is further detailed, and the calculation method of axial compression ratio of steel tube and concrete composite columns is added; (9) In combination with JGJ 3-2010 Technical specification for concrete structures of tall building, the relevant regulations of Classes A and B reinforced concrete structures are supplemented; (10) The conditions and design measures for liberalizing the seismic shear force limit of the frame part in the frame-core tube structure are supplemented; (11) The seismic design requirements of slab-column structure are supplemented; (12) The condition of basement roof as the embedded part of superstructure is more clear, and the ratio of lateral stiffness of the first story underground to the first story aboveground is different, and the estimation method of stiffness ratio is supplemented; (13) The seismic design requirements of buildings with reinforced small block masonry walls are added in the text (in the annex as for the national standard), and further supplemented and improved; (14) The relevant regulations on seismic design for multi-story split-level brick masonry buildings are added; (15) The relevant regulations on seismic design of precast concrete structures are added; (16) The tall buildings are excluded from seismic design of steel structure buildings, since Shanghai has issued DG/TJ08-32-2008 Specification for steel structure design of tall buildings, and the concept of seismic grade is not adopted; (17) The provisions of isolation and energy-dissipation design are revised, which is more in line with the actual situation of Shanghai; (18) The clauses concerning single-story brick column factory buildings, and earth, wood and stone buildings are deleted.
The provisions printed in bold type in this code are compulsory and must be enforced strictly. With respect to GB 50011-2010 Code for seismic design of buildings, this code has added the following mandatory provisions: 7.1.4 related to precast RC structures; 8.6.1, 8.6.6, 8.6.8 and 8.6.15 related to buildings with reinforced small block masonry wall; and 8.7.3 related to multi-story split-level brick masonry buildings.
General Market Management Station of Shanghai Building Material Industry
April, 2013
Code for seismic design of buildings
1 General
1.0.1 This code is prepared with a view to implementing the national laws and regulations on earthquake prevention, disaster mitigation and architectural engineering, executing the prevention first policy and reducing the earthquake damage, casualty and economic loss after taking seismic protection measures.
1.0.2 This code is applicable to the seismic design, isolation and energy-dissipation design of general buildings on Categories III and IV sites in Shanghai. Performance-based seismic design of buildings may be carried out according to the basic methods specified in this code. The seismic design for special buildings and buildings with special industry requirements shall comply with relevant standards and specifications.
1.0.3 The buildings designed according to this code shall meet such seismic protection objectives that the major structures may be used continuously without damage or repair when affected by frequent earthquakes with the seismic protection intensity lower than that in this area; they may be damaged while can still be used after general repair when affected by an earthquake with the seismic protection intensity equivalent to that in this area; and they shall not encounter collapse or serious damage endangering life when affected by a rare earthquake with the seismic protection intensity higher than that in this area. For buildings with special functional or other requirements, the protection objectives higher than the basic ones can be adopted in the performance-based seismic design (if adopted).
1.0.4 The seismic design of buildings complying with this code shall also meet the requirements of the current relevant standards of the nation and Shanghai in addition to those of this code.
1.0.5 The seismic design of buildings shall follow the principle of equal importance on conceptual design and calculation as well as the design idea of unified aesthetic appearance and seismic safety of structures.
2 Terms and symbols
2.1 Terms
2.1.1
seismic protection intensity
seismic intensity which is approved as the criterion of seismic precaution of an area according to the authority specified by the nation
Note: "Intensities 6, 7 and 8" in this code is short for "seismic protection intensities 6, 7 and 8".
2.1.2
seismic protection criterion
scale for measuring the seismic protection requirements, which is determined by seismic protection intensity or design parameters of earthquake ground motions and seismic protection categories of buildings
2.1.3
seismic ground motion parameter zonation map
map in which the whole country is divided into areas with different seismic protection requirements, based on the seismic ground motion parameters (the intensity of earthquake action is expressed by acceleration)
2.1.4
earthquake action
dynamic action of structure caused by ground motion, including horizontal earthquake action and vertical earthquake action
2.1.5
design parameters of earthquake ground motions
seismic acceleration (speed and displacement) time history curve, acceleration response spectrum and peak acceleration for seismic design
2.1.6
design basic acceleration of ground motions
design value of acceleration of earthquake with exceeding probability of 10 % during the 50-year design reference period
2.1.7
design characteristic period of ground motions
periodic value corresponding to the start point of descending segment reflecting such factors as earthquake magnitude, epicentral distance and site category in the seismic influence coefficient curve used for seismic design
2.1.8
site
location of the engineering groups, with similar response spectrum characteristics, within the scope equivalent to the plant area, residential quarter and natural village or the plane area not less than 1.0 km2
2.1.9
seismic concept design of buildings
process of making the general arrangement for the buildings and structures and of determining details, based on the fundamental design principles and design concept obtained from the experiences in the earthquake disasters and projects
2.1.10
details of seismic design
various detail requirements which must be taken for structural and nonstructural parts generally without calculation according to seismic concept design principle
2.1.11
seismic measures
seismic design content excluding earthquake action calculation and resistance calculation; it includes details of seismic design
2.1.12
seismic performance levels
damage status of buildings after earthquakes and affection degree of their functions to continued use
2.1.13
seismic performance objectives
desired seismic performance levels of buildings based on the ground motion level
2.1.14
performance-based seismic design
design with reasonable seismic performance objectives and based on the seismic performance analysis of buildings, so that the designed buildings have the expected seismic performance when subjected to possible earthquakes in future
2.1.15
precast RC structure
reinforced concrete structure produced by precasting and assembly technology
2.1.16
precast composite RC wall
seismic composite reinforced concrete wall with precast concrete (PCF board) on one side and cast-in-place concrete on the other side
2.1.17
shear wall structure with precast composite RC wall
shear wall structure with precast composite RC wall as the exterior wall, and ordinary seismic reinforced concrete wall as the interior wall
2.1.18
reinforced small block masonry wall
wall reinforced with vertical and horizontal steel bars in the holes and grooves of small hollow concrete blocks that are filled with grout concrete so as to bear vertical and horizontal earthquake action
2.2 Symbols
2.2.1 Actions and effects
FEk, FEvk——the standard value for total structural horizontal and vertical earthquake action;
GE, Geq——the representative value of structure (member) gravity load and total equivalent gravity load in earthquake;
wk——the standard value of wind load;
SE——the earthquake action effect (bending moment, torque, axial force, shear force, stress and deformation);
S——the fundamental combination of earthquake action effect and other load effects;
Sk——the effect of action and standard value of load;
M——the bending moment;
N——the axial pressure;
V——the shear force;
p——the pressure on bottom of foundation;
u——the lateral displacement;
θ——the displacement angle of story.
2.2.2 Material properties and resistance
K——the stiffness of structure or member;
R——the bearing capacity of structural member;
f, fk, fE——the design value, standard value and seismic design value of various material strength (including the bearing capacity of subgrade) respectively;
[θ]——the limit for displacement angle of story.
2.2.3 Geometric parameters
A——the sectional area of member;
As——the sectional area of steel bar;
B——the total width of structure;
H——the total height of structure and column height;
L——the total length of structure (unit);
α——the distance;
as, ——the minimal distance from the force concurrence point of all longitudinal tensile and compressive steel bars to the margin of section;
b——the section width of member;
d——the depth or thickness of soil layer, or diameter of steel bar;
h——the height of calculated story or sectional height of member;
l——the length or span of member;
t——the thickness of shear wall or thickness of floor slab.
2.2.4 Calculation coefficients
α——the horizontal seismic influence coefficient;
αmax——the maximum value of horizontal seismic influence coefficient;
αvmax——the maximum value of vertical seismic influence coefficient;
γG, γE, γw——the partial coefficient of action;
γRE——the seismic adjustment factor of bearing capacity;
ζ——the calculation coefficient;
η——the enhancement or adjustment factor of earthquake action effect (internal force and deformation);
λ——the slenderness ratio or scale coefficient of member;
λv——the characteristic value of minimum stirrups;
ξy——the yield strength coefficient of structure (member);
ρ——the reinforcement ratio or ratio;
φ ——the stability coefficient of compressive member;
Ψ——the combination value coefficient or influence coefficient.
2.2.5 Others
T——the natural vibration period of structure;
N——the standard penetration blow count;
Ile——the liquefaction index of subgrade in earthquake;
Xji——the vibration mode coordinate of displacement (relative displacement of the ith mass point of the jth vibration mode in Direction x);
Yji——the vibration mode coordinate of displacement (relative displacement of the ith mass point of the jth vibration mode in Direction y);
Фji——the vibration mode coordinate of rotation (relative rotation of the ith mass point of the jth vibration mode in rotating direction);
n——the total number, such as number of stories, mass points, steel bars and spans, etc.;
vse——the equivalent shear wave velocity of soil layer.
3 Basic requirements of seismic design
3.1 Category and criterion for seismic protection of buildings
3.1.1 For all buildings under seismic protection, seismic protection category and seismic protection criterion shall be determined according to the requirements of the current national standard GB 50223 Standard for classification of seismic protection of building constructions.
3.1.2 The seismic protection intensity 7 can apply to all districts and counties in Shanghai.
3.2 Seismic influences
3.2.1 The seismic influences suffered by the locations of the buildings shall be characterized by the design basic acceleration of ground motion and the design characteristic period of ground motion corresponding to the seismic protection intensity.
3.2.2 If Shanghai is in frequent earthquakes and earthquakes of seismic protection intensities, the design characteristic period of ground motion in Category III site shall be 0.65 s and that in Category IV site shall be 0.9 s; if Shanghai is in rare earthquakes, the design characteristic period of ground motion in Category III and Category IV sites shall be 1.1 s. The design basic acceleration of ground motion corresponding to the seismic protection intensity shall be selected according to those specified in Table 3.2.2.
Table 3.2.2 Corresponding relationship between seismic protection intensity and design basic acceleration of ground motion
Seismic protection intensity 6 7 8
Design basic acceleration of ground motion 0.05 g 0.10 g 0.20 g
Note: g just above is the gravity acceleration.
3.3 Site and subgrade
3.3.1 To select a building site, comprehensive evaluation shall be made on favorable, general, unfavorable and dangerous sections for seismic resistance according to relevant data such as engineering requirement, seismic activity, engineering geology and seismic geology: For unfavorable section, requirements for avoiding it shall be put forward; when it is impossible to avoid it, effective measures shall be taken; For dangerous section, it is strictly prohibited to build Categories A and B buildings, and Category C buildings shall not be built.
3.3.2 The design of subgrade and foundation shall meet the following requirements:
1 The foundation of the same structural unit should not be set on the subgrades with completely different properties;
2 Natural subgrade and pile foundation should not be adopted in the same structural unit. If different types of foundations are adopted or the buried depth of the foundation is significantly different, corresponding measures shall be taken at the relevant parts of the foundation and superstructure according to the settlement difference between the two parts of the subgrade and foundation as well as to ensure reliable transmission of horizontal forces in the two parts during the earthquake;
3 For the subgrade composed of soft clay, liquefied soil, new fill or extremely non-uniform soil, corresponding measures shall be taken according to the differential settlement of subgrade in earthquake and other adverse influence.
3.3.3 The site, subgrade and foundation of buildings on slopes shall meet the following requirements:
1 Slope stability evaluation and prevention scheme and suggestions shall be provided during investigation of site of buildings on slopes.
2 The slope engineering shall adapt to the seismic protection requirements based on local conditions, according to the geological and topographic conditions and use requirements. The slope design shall meet the requirements of the current national standard GB 50330 Technical code for building slope engineering; during stability check, the relevant friction angle shall be corrected accordingly according to the seismic intensity.
3 The building foundation near the slope shall be designed for seismic stability. Enough distance shall be reserved between the foundation of the buildings and the edge of soil slope, which shall be determined according to the seismic intensity, and measures shall be taken to prevent the subgrade and foundation from being damaged during earthquake.
3.4 Regularity of building configuration and structural assembly
3.4.1 Architectural design shall define the regularity of building configuration according to the requirements of seismic concept design. Irregular buildings shall be reinforced as specified; normal irregular buildings shall be specially researched and demonstrated, for which special reinforcement measures shall be taken; seriously irregular buildings shall not apply.
Note: Building configuration refers to the change of plane shape, elevation and vertical profile of a building.
3.4.2 Architectural design shall emphasize the influence of the regularity of plane, elevation and vertical profile on seismic performance and economic rationality, In order to avoid the abrupt change of lateral stiffness and bearing capacity, it is suggested to select regular shape, regular and symmetrical layout of lateral-force-resisting members, uniform change of lateral stiffness along vertical direction, and gradual decrease of cross-section size and material strength of vertical lateral-force-resisting members from bottom to top.
The seismic design of the irregular buildings shall comply with the relevant provisions of 3.4.4 of this code.
3.4.3 The plane and vertical irregularities of building configuration and structural assembly shall be divided according to the following requirements:
1 Concrete buildings, steel buildings and steel-concrete hybrid buildings, in which a type of plane irregularity listed in Table 3.4.3-1 or a type of vertical irregularity listed in Table 3.4.3-2 or a similar irregularity exists, shall belong to irregular buildings;
Table 3.4.3-1 Main type of plane irregularity
Irregularity type Definition and indicator limit
Torsional irregularity The maximum elastic horizontal displacement (or inter-story displacement) of story under specified horizontal force is greater than 1.2 times of the mean of elastic horizontal displacement (or inter-story displacement) at both ends of this story
Concave-convex irregularity The concave length of structural plane is greater than 30 % of the overall dimension in corresponding projection direction; or the convex length is greater than 30 % of the overall dimension in corresponding projection direction and the convex width is less than 50 % of the convex length
Local discontinuity of floor slab The dimension of floor slab and the stiffness of plane change rapidly, for instance, the effective width of floor slab is less than 50 % of the typical width of floor slab at this story, or the opening area is greater than 30 % of the floorage of this story or split-level exists in larger story (split-level height is greater than the sectional height of floor beam or greater than 0.6 m)
Table 3.4.3-2 Main type of vertical irregularity
Irregularity type Definition and indicator limit
Lateral stiffness irregularity The lateral stiffness of this story is less than 70 % of the adjacent upper story or less than 80 % of the mean lateral stiffness of the adjacent three stories; except for the top story or out-of-roof small buildings, the horizontal dimension of partial take-in is greater than 25 % of the adjacent lower story
Discontinuity of vertical lateral-force-resisting member The internal forces of vertical lateral-force-resisting members (columns, shear walls and seismic support) are transmitted downward by horizontal conversion members (beams, trusses, etc.)
Abrupt change in story bearing capacity Lateral-force-resisting structures have an inter-story shear capacity of less than 80 % of the adjacent upper story
2 The division of plane and vertical irregularities of masonry buildings, single-story industrial factory buildings, single-story spacious buildings, long-span roof buildings and underground buildings shall meet the provisions of relevant clauses of this code.
3 In case of a building with many irregularities or with an irregularity largely exceeding the specified reference index shall be a seriously irregular building.
Foreword i
1 General
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements of seismic design
3.1 Category and criterion for seismic protection of buildings
3.2 Seismic influences
3.3 Site and subgrade
3.4 Regularity of building configuration and structural assembly
3.5 Structural system
3.6 Structural analysis
3.7 Nonstructural members
3.8 Isolation and energy-dissipation design
3.9 Structural materials and construction
3.10 Performance-based seismic design of buildings
3.11 Strong seismic response observation system of buildings
4 Site, subgrade and foundation
4.1 Site
4.2 Judgment and treatment for subgrade liquefaction
4.3 Seismic strength check for subgrade and foundation
4.4 Seismic measures
5 Earthquake action and seismic checking for structures
5.1 General
5.2 Calculation of horizontal earthquake action
5.3 Calculation of vertical earthquake action
5.4 Seismic checking of section
5.5 Seismic checking for deformation
6 Multi-story and tall reinforced concrete buildings
6.1 General
6.2 Essentials in calculation
6.3 Basic details of seismic design for frame structures
6.4 Basic details of seismic design for shear wall structures
6.5 Basic details of seismic design for frame-shear wall structures
6.6 Seismic design requirements for slab-column-shear wall structures
6.7 Seismic design requirements for tube structures
7 Precast RC structures
7.1 General
7.2 Seismic design requirements for precast RC frame
7.3 Seismic design requirements for precast composite RC wall
8 Masonry buildings and masonry buildings with RC frames on ground stories
8.1 General
8.2 Essentials in calculation
8.3 Details of seismic design for multi-story brick masonry buildings
8.4 Details for multi-story small block buildings
8.5 Details of seismic design for masonry buildings with frame-shear wall on ground story
8.6 Seismic design for buildings with reinforced small block masonry walls
8.7 Seismic design for multi-story split-level brick masonry buildings
9 Steel buildings
9.1 Multi-story steel buildings
9.2 Single-story steel factory building
10 Single-story factory buildings with RC columns
10.1 General
10.2 Essentials in calculation
10.3 Details of seismic design
11 Large-span buildings
11.1 Single-story spacious buildings
11.2 Long-span roof buildings
12 Seismically isolated and energy dissipation buildings
12.1 General
12.2 Essentials in design of seismically isolated buildings
12.3 Essentials in design of energy-dissipation buildings
13 Nonstructural members
13.1 General
13.2 Essentials in calculation
13.3 Essential seismic measures for architectural nonstructural members
13.4 Essential seismic measures for supports of mechanical and electrical components
14 Subterranean buildings
14.1 General
14.2 Essentials in calculation
14.3 Details of seismic design and anti-liquefaction measures
Annex A Time history curves of earthquake ground motion acceleration
Annex B Requirements for seismic design of high strength concrete structures
Annex C Seismic design requirements of prestressed concrete structures
Annex D Seismic checking of section for the core area of beam-column joint of frame structure
Annex E Seismic design requirements for transition story structures
Annex F Seismic design for composite steel bracing – concrete frame structures and composite steel frame - concrete core tube structures
Annex G Seismic design for multi-story industrial factory buildings
Annex H Adjustment of transverse earthquake action effect of plane bent frame of single-story factory buildings
Annex J Seismic checking for single-story reinforced concrete column factory building in longitudinal direction
Annex K Simplified calculation of seismic isolation design and seismic isolation measures for masonry structures
Annex L Reference methods for performance-based seismic design
Explanation of wording in this code
List of quoted standards
