Page 185 - Advanced Design Examples of Seismic Retrofit of Structures

Example of an RC Building Retrofitted by RC Shear Walls Chapter 3 177

Controlling the Foundation In the field sampling and data collection of struc-
tural members, the thickness of the foundation of the northern and the southern
building parts were determined to be 120cm and 100cm, respectively. The
upper and the lower reinforcements were φ20@150 cm. The flexural behavior
of this section is shown in Fig. 3.39. The flexural strength of the foundation
6
under the columns is approximately 2.6 10 Nm/m, because of the wedge
shape of the foundation in these areas as well as the auxiliary reinforcements
(Fig. 3.40).
The shear strength of the foundation is determined based on
p
p ffiffiffiffi ffiffiffiffiffiffiffiffi
f ¼ 0:53 0:75 250 ¼ 0:6MPa, which leads to 600kN/m
0
v c ¼ 0:53∅ s
c
and 1000kN/m of capacity for locations other than under columns and the loca-
tions under columns, respectively.
Foundation Retrofit Design
The controls of the soil pressure and foundation are carried out for the CP
performance level under Earthquake-2. It is noted that there are no acceptance
criteria for the soil settlement for the CP performance level.

Controlling the Soil Pressure Under Foundation Because, in the modeling
of the building, the supports were assumed to be rigid, the behavior of the soil
under the foundation is deformation-controlled and its adequacy is controlled
according to Eq. (3.14) [1].

1
FIG. 3.39 Flexural behavior of the foundation section ( 10 kNm/m).