【正文】 B Liquefaction settlement shall be partially eliminated, or make treatment to the foundation and superstructure Liquefaction settlement shall be totally eliminated, or liquefaction settlement is partially eliminated plus treatment to the foundation and superstructure Liquefaction settlement shall be totally eliminated. C Treatment to the foundation and superstructure, and it is also possible not to take any provision Treatment to the foundation and superstructure, or provision with higher requirements Liquefaction settlement shall be totally eliminated, or liquefaction settlement is partially eliminated plus treatment to the foundation and superstructure D It is permissible not to take any provision It is permissible not to take any provision Treatment to the foundation and superstructure, or other economic provisions Building Layout and Structural Type Selection Antiseismic design specification for buildings GBJ 11 – 89 If a building with plicated shape is not provided with any antiseismic joint, its local stress and deformation concentration and torsion effect shall be estimated, and its portion likely to be damaged be determined, to take measures for better antiseismic capacity。 IV. Provisions shall be made to increase the antiseismic capacity at possible weak portions. — 4 — Structural Materials Antiseismic design specification for buildings GBJ 11 – 89 Any special requirement of the antiseismic structure on materials and construction quality shall be indicated in the design documents. The performance parameters of structural materials shall ply with the following minimum requirements: I. The strength grade of clay bricks shall be no lower than , and that of mortar for the brick masonry not lower than 。 II. In any structure with angular antilateral force members, the horizontal seismic action in the direction of each antilateral member shall be taken into consideration。 amax — Max. value of seismic influence coefficient。 ?G — Gravitational load partial safety factor, normally taken as , and can be taken when the gravitational load effect is favorable to the bearing capacity of the structure。 Ehk — Horizontal seismic action standard value。 CG ,CEh ,CEv ,Cw — Respectively the action effect coefficient of gravitational load, horizontal seismic action, vertical seismic action and wind load, and they should be multiplied with corresponding amplifying coefficient or adjustment coefficient. Partial safety factor of seismic action Table Seismic action ?Eh ?Ev Only taken into account horizontal seismic action Not taken into account Only taken into account vertical seismic action Not taken into account Both horizontal and vertical seismic action are taken into account — 7 — The following design expression shall be adopted for the sectional antiseismic proof calculation for structural members: S≤ R/?RE () Where ?RE — Bearing capacity antiseismic adjustment coefficient, shall be taken from Table 。 and tying joints shall be adopted for other cases, the stirrup spacing within the reinforcement splicing length shall be no greater than 100mm。 VI. The stirrups shall be welded when the total reinforcement ratio of longitudinal reinforcement in a column has exceeded 3%. Reinforced concrete structures shall be adjusted for seismic action effect. The length of densified zone at beam ends, maximum spacing and minimum diameter of stirrups shall be taken from Table . When the reinforcement ratio of beam end longitudinal tensile reinforcement is greater than 2%, the value of minimum diameter of stirrups in the table shall be increased by 2mm. Length of densified zone at beam ends, maximum spacing and minimum diameter of stirrups Table Antiseismic grade Length of densified zone (using the greater value) (mm) Stirrup max. spacing (using the min. value) (mm) Stirrup min. diameter ? 2 hb,500 hb/4, 6d, 100 Φ 10 ? , 500 hb/4, 8d, 100 Φ 8 ? , 500 hb/4, 8d, 150 Φ 8 ? , 500 hb/4, 8d, 150 Φ 6 Note: d is the diameter of longitudinal reinforcement。 III. For frame columns and columns with the ratio of height to sectional height not greater than 4, the stirrup spacing shall not be greater than 100mm. The vertical and transversal distributed reinforcement in antiseismic walls shall be in doublerow arrangement at all portions for Grade I and at reinforced portions for Grade II。 the total height and number of storeys of buildings with very few transversal walls on each floor shall be further reduced as appropriate according to actual conditions. Limit values for total height (m) and number of storeys of masonry buildings Table Type of masonry Min. wall thickness (m) Intensity 6 7 8 9 Height Storeys Height Storeys Height Storeys Height Storeys Clay brick 24 8 21 7 18 6 12 4 Small concrete blocks 21 7 18 6 15 5 Not appropriate Note: The total building height refers to the height from outdoor ground surface to eave, and it can be counted as from the outdoor ground surface for full basement. The structural system of multistoreyed buildings shall ply with the following requirements: I. The structural system with transversal wall bearing the load or longitudinal and transversal wall bearing the load jointly shall be adopted in preference。 fv — Shearing strength design value for masonry in nonantiseismic design。 when the wall body is weakened, reinforcing measures shall be taken for the wall body。 for tall highrise buildings on ground type III for Grade IV, the minimum reinforcing ratio of distributed reinforcement at ordinary portions shall be no less than %. Reinforcing requirements for distributed reinforcement in antiseismic walls Table Antiseismic grade Min. reinforcing ratio (%) Max. spacing (mm) Mi