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Code Name

National Standards of the People's Republic of China

Code for Seismic Design of Buildings (GB50011-2010)

(Issued: May.31, 2010, Actualized: Dec. 1, 2010)

Issued by

Ministry of Housing and Urban-Rural Development, joint with General Administration of Quality Supervision, Inspection and Quarantine

Revision

TJ11-74 (1974), TJ11-78 (1978), GBJ11-89 (1989), GB50011-2001 (2001), GB50011-2010 (2010)

Horizontal Seismic
Forces (Based Shear Method)

FEk :  standard value of the total horizontal seismic action of the structure

Geq :  Total equivalent seismic weight of a building. The repetitive value of the total gravity load shall be used when the structures is modeled as a single-mass system; when the structure is modeled as multi-mass system, 85% of the representative of the total gravity load may by used. ( Table 1)

α1:   horizontal seismic effective coefficient corresponding to the fundamental period of the structure (Figure 1)

α =Seismic coefficient

T  =Natural period of structure

T= Design Characteristic Period of Ground Motion (Table 2).

αmax  = Maximum value of the seismic coefficient( Table 3)

For 0.1<T< Tg , α=αmax

      for  Tg<T< 5Tg

  attenuation index for Tg<T< 5Tg

  damping ratio

  for  5Tg<T< 6.0

 slope adjustment coefficient for Tg<T< 5Tg, it equal to 0.0 when it less than 0.0

 damping adjustment coefficient, it equal to 0.55 when it less than 0.55

Fi:   standard value of horizontal seismic action applied on mass (Figure 2)

Gi, Gj: representative values of gravity load concentrated at the masses of i and j, taken as the combination of dead load and live load (Table 1)

Hi, Hj: calculated height of masses i and j from the base of building respectively

δn:  additional seismic action coefficient at the top level of building (Table 4)

ΔFn: Additional seismic force action at the top of building

(Updated on 31 July,2012)