## 9 Conclusions  
This paper highlights some issues that are affecting the Lebanese seismic design and gives hints and tools to suitably address them. A main issue is related to the excess of design response spectra that are admitted by the Lebanese code, which may create confusion in civil engineering practice. Another issue is the reference that is made to foreign codes that conflict with each other and/or are not mandatory anymore in their countries. A correlated issue concerns the difficulty to get all the parameters that are needed to obtain the Lebanese design response spectra by following the indications of such foreign codes. In addition to the ambiguity of the design response spectra to be adopted, there are also matters related to the scarcity of recorded earthquakes in the Lebanese area which makes it difficult to obtain suitable suites of spectrum-consistent earthquakes to carry out transient analyses. Finally, even when appropriate spectrum-consistent earthquakes are found, their excessive length may be a further cumbersome problem. Sorting through the four codes indicated by the Lebanese code and the applicative instructions given for each of them, this paper provides all the design response spectra that can be used for the Lebanese design. This tidying up job, which was not fully completed before, led to supply formulas, tables of parameters and graphs that can be very useful for Lebanese practitioners. The comparison evidenced the differences between the many design spectra that are indistinctly admitted by the Lebanese code which is thus found to implicitly admit different safety levels for similar buildings grounded on the same soil class. The comparative study also showed that the topographical effects are not accounted for in most of the design spectra, the only code providing topographical factors being the obsolete French code. This may add further inconsistencies to the seismic design, as showed by the comparison of the results. Although the aim of this paper is obviously far from giving specific design instructions, this matter being the responsibility of the Lebanese Government, the use of two codes that are currently in force (among the four referred to) is suggested in this paper, namely the International Building Code (IBC) and the Eurocode 8 (EC8). The first one is the official seismic code in the USA as well as a reference code in many other countries, like Chile. The second one is the reference code for many of the European countries and it is even announced to be the only future reference code in Lebanon. When EC8 is the Lebanese reference code, it is suggested to also provide topographical factors to obtain different design response spectra for different topographical conditions, as it is done, for instance, by the Italian code. Figure 13: (**a**) Roof displacements and (**b**) base shear forces, calculated through LTHAs under the accelerograms generated for ECS. To address the matter of lack of proper accelerograms to be used for the seismic assessment of the Lebanese structures through time-history analyses, wide research in many seismic databases was carried out which eventually led to finding some strong earthquakes that occurred along the Dead Sea Transform Fault. Those records were assumed to be seismogenically representative of the seismic events occurring in Lebanon. By elaborating them, both in the time and in the frequency domain, suitable sets of accelerograms that are consistent with the design response spectra of IBC and of EC8 are found for the different considered soil categories. The synthetization process was carried out through a spectral matching method by considering a 10% upper and lower mismatch tolerance. Since the time length of such accelerograms is typically rather long, which implies a large computational burden, the matter of shortening the spectrum-consistent accelerograms was also addressed in the paper. Based on the Arias intensity of a given earthquake, a procedure is proposed, which can be implemented with the help of commercial matching tools.