【正文】 V. The flue duct, air duct and rubbish duct shall not weaken the wall body。 hb the beam height. The minimum total reinforcement ratio of column longitudinal reinforcement shall be taken from Table , and the values in the table shall be increased by for tall highrise buildings on ground of Class IV. Min. total reinforcement ratio of column longitudinal reinforcement (%) Table Type Antiseismic grade I II III IV Central and side columns in frames Corner columns in frames and frame columns The stirrup spacing and diameter in column densified zone shall ply with the following requirements: I. Under normal conditions, the maximum spacing and minimum diameter of stirrups shall be taken from Table 。 R — Bearing capacity design value of structural member. Bearing capacity antiseismic adjustment coefficient Table Material Structural member Loading status γRE Steel Columns Support between columns in structural steel factory buildings Support between columns in reinforced concrete factory buildings Welding seam on members Deflected pression Masonry Antiseismic walls with structural columns and stems at both ends Other types of antiseismic walls Shearing Shearing Reinforced concrete Beams Columns with axial pression ratio less than Columns with axial pression ratio not less than Antiseismic walls Members of various types Bending Deflected pression Deflected pression Deflected pression Shearing and Deflected tensile In the calculation of standard value of rarely encountered seismic action, the horizontal seismic influence coefficient shall be taken as per Fig. , and its maximum value shall be taken as per Table . Max. value of horizontal seismic influence coefficient for rarely encountered seismic action Table Intensity 7 8 9 amax Design and construction regulations for bent structures JGJ 7 – 91 In areas with antiseismic design protection intensity of degrees 8 or 9, vertical antiseismic proof calculation shall be performed for bent roofing structures. In areas with antiseismic design protection intensity of degree 8, the horizontal antiseismic proof calculation may be omitted for medium and smallspan bent structures with peripheral supports。 ?Eh, ?Ev — Respectively the partial safety factor of horizontal and vertical seismic action, and shall be taken from Table 。 III. For structures with apparent uneven or asymmetric mass and rigidity distribution, the torsion effect of horizontal seismic action shall be taken into consideration。 when antiseismic joints are provided, sufficient width shall be provided according to the intensity, ground class and building type, and the superstructures on both sides of the joint shall be pletely separated. All expansion joints and settlement joints shall ply with the requirements for antiseismic joints. An antiseismic structural system shall ply with all the following requirements: I. There shall be explicit calculation sketches and reasonable transmission route for the seismic actions。 II. Such consequences as damage to part of the structure or members resulting in the loss of antiseismic capacity or the bearing capacity of the gravitational force in the whole system shall be avoided。 IV. The vertical seismic action shall be taken into consideration for large span structures and long cantilever structures for intensity 8 and 9 degrees, and for highrise buildings for intensity 9 — 5 — degrees. In the calculation of seismic action, the gravitational load characteristic value of the building shall be taken as the sum of the standard value of the selfweight of the structure and members and accessories and the bined value of all the variable loads. The bined value coefficient of all the variable loads shall be taken from Table . Combined value coefficient Table Type of variable load Combined value coefficient Snow load Live load on roofing Not taken into consideration Live load on flooring considered according to actual conditions Live load on flooring considered as equivalent evenly distributed load Library store and archive store Other civilian buildings The seismic influence coefficient of building structures shall be taken as per Fig. on the basis of the near earthquake, far earthquake, site class and selfvibration period of structure, and its lower limit shall be no less than 20% of the maximum value。 ?w — Wind load partial safety factor, shall be taken as 。 in areas with antiseismic design protection intensity of degree 9, the horizontal — 8 — antiseismic proof calculation shall be performed for all bent structures. 3. Antiseismic Design for Concrete Structures Multistoreyed and Highrise Reinforced Concrete Buildings Antiseismic design specification for buildings GBJ 11 – 89 Different antiseismic grades shall be applied for reinforced concrete buildings according to the intensity, structural type and building height, and they shall ply with the corresponding requirements in calculation and structural provisions. In the frame – antiseismic wall structures, when the seismic tipping moment borne by the antiseismic wall is not greater than 50% of the total seismic tipping moment of the structure, the antiseismic grade of the frame section shall be determined as for frame structure. Note: “Grade I, II, III and IV” as referred to in this section is the abbreviated reference to “antiseismic grade I, II, III and IV”. When assembled flooring and roofing is adopted for the frame – antiseismic wall structure, provisions shall be made to ensure the integrity of the building and the roofing and their reliable connection with the antiseismic walls. The antiseismic walls for the top storey, staircas