F. K. Kong MA, MSc, PhD, CEng, FICE, FIStructE, R. H. Evans CBE, DSc, D ès Sc, DTech, PhD, CEng, FICE, FIMechE, FIStructE (auth.)-Reinforced and Prestressed Concrete-Springer US (1987)

Problems 375
Step3
Determine the permissible tendon zone (eqns 9.2-18 to 9.2-21).
Step4
Compute the initial prestressing force P on the basis of an estimated loss
ratio a (eqn 9.3-7).
StepS
Determine the number and arrangement of tendons [10,14-16]. Select a
suitable prestressing system (see specialist texts) [10,14-16).
Step6
Calculate the loss ratio a (see BS 8110: Clauses 4.8 and 4.9). If a thus
calculated differs too much from the estimated value in Step 4, revise
Steps 4 and 5.
Step7
Check stresses at transfer and determine the permissible tendon zone for
conditions at transfer.
StepS
Select the tendon profile. Use ideal shear profile (eqn 9.2-27) if
possible.
Step9
Check ultimate flexural strength as explained in Section 9.5.
SteplO
Check ultimate shear resistance and design shear reinforcement if
necessary, as explained in Section 9.6.
Stepll
Check ultimate torsional resistance and design torsion reinforcement if
necessary; see Section 9.7.
Stepl2
Check short-term and long-term deflections; see Section 9.8.
9.10 Computer programs
(in collaboration with Dr H. H. A. Wong, University of Newcastle upon
Tyne)
The FORTRAN programs for this Chapter are listed in Section 12.9.
See also Section 12.1 for 'Notes on the computer programs'.
Problems
9.1 The design procedure of Section 9.9 first considers the stress
conditions in service (eqns 9.2-4 to 9.2-7) and then those at transfer (eqns
9.3-1 to 9.3-4). Of the eight stress conditions considered, the following
four are often not critical:
eqns (9.2-5) and (9.2-7) eqns (9.3-1) and (9.3-3)