PSI - Issue 42

H. Mazighi et al. / Procedia Structural Integrity 42 (2022) 1714–1720 19 000 – 000

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H.Mazighi and .K.Mihoubi / Stru tur l Integrity Procedia 00

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b Fig. 1. (a) Koyna earthquake; (b) Saguenay earthquake.

3.3. Hydrodynamic loading The Koyna dam was modelled considering hydrodynamic pressure. It is obvious that the proportion of hydrodynamic pressure decreases in parabolic form the base level to the normal pool level along the dam height at upstream (Fig.2.), the expression is given by Westergaard,(1933): = 7 8 ℎ √1 − ℎ ℎ (9) The applied hydrodynamic load has been implemented in ABAQUS using the subroutine UEL, written in FORTRAN. The UEL subroutine allows for user-defined computation of nodal force vectors. For each step time of the analysis, the UEL subroutine is evaluated, and hydrodynamic force is calculated. Figure 3 shows the flow chart to solve the displacement governing equations (eq.1) applied in this study.