Page 351 - Advanced Design Examples of Seismic Retrofit of Structures

328 Advanced Design Examples of Seismic Retrofit of Structures

TABLE 5.22 Initial Stiffness, Base Shear Corresponding to the Target
Displacement, and Yield Strength of the Sports Building
Load K i K e V t V y V t > T e
Pattern (ton/cm) (ton/cm) (ton) (ton) 0.8V y (s)
PX1 0.871 0.832 9.324 9.573 OK 2.36
PY1 1.98 1.98 9.91 9.91 OK 0.31
PX2 1.003 0.88 13.48 11.95 OK 2.46
PY2 2.34 2.34 11.62 11.62 OK 0.31
PX3 0.878 0.823 9.405 9.702 OK 2.38
PY3 2.0 2.0 9.98 9.98 OK 0.31
PX4 1.011 0.899 13.6 12.54 OK 2.45
PY4 2.36 2.36 11.72 11.72 OK 0.31

The prescriptive expected bearing capacity, q c , for a spread footing shall be cal-
culated using Eq. (8.1):

(5.34)
q c ¼ 3q allow
where q allow ¼allowable bearing pressure specified in available documents for
the gravity load design of shallow foundations (dead plus live loads).
Based on geotechnical tests and field observations, the soil design parame-
ters for the foundations of the two example buildings are derived and presented
in Table 5.23. The geometrical characteristics of the foundation of the example
buildings are presented in Fig. 5.15.

TABLE 5.23 Soil Design Parameters Based on Geotechnical Tests and Field
Observations
Pad Foundation Strip Footing
Width q a Width q a
2
2
(m) (kg/cm ) q allow 53×2×q a (m) (kg/cm ) q allow 53×2×q a
1.0 1.682 10.092 0.8 1.467 8.802
1.7 1.797 10.782 1.6 1.633 9.798
2.2 1.88 11.28