The paper aims to contribute to the preservation of high valuable historic masonry structures and historic urban landscapes through the combination of geotechnical, structural engineering. The main objective of the study is to conduct finite element analysis (FEA) of bearing saturated soft clay soil problems and induced structural failure mechanisms. This analysis is based on experimental and numerical studies using coupled PLAXIS 3D FE models. The paper presents a geotechnical analytical model for the measurement of stresses, deformations, and differential settlement of saturated clay soils under colossal stone/brick masonry structures. The study also discusses the behavior of soft clay soils under Qasr Yashbak through numerical analysis, which helps in understanding the studied behavior and the loss of soil-bearing capacity due to moisture content or ground water table (G.W.T) changes. The paper presents valuable insights into the behavior of soft clay soils under colossal stone/ brick masonry structures. The present study summarized specific details about the limitations and potential sources of error in Finite Element Modeling (FEM). Further field research and experimental analysis may be required to address these limitations and enhance the understanding of the studied soft clay soil behavior. The geotechnical problems in historic monuments and structures such as differential settlement are indeed important issues for their conservation since it may induce serious damages. It deserves more in-depth researches.

Aleppo, one of the oldest inhabited world heritage cities in the world, was struck by a destructive earthquake on February 06, 2023. Its iconic citadel built on a historical hill and surrounded by a protective moat, was severely damaged. However, the main entrance tower and the massive arched masonry bridge composed of an inclined deck and a series of unequal pillars height, constructed over the moat, survived the earthquake with minor apparent damages. In the light of a damage identification purpose, characterization of dynamic properties, and a health monitoring plan, an experimental dynamic identification campaignwas conducted on the historic structure, and sonic testingwas undertaken on the bridge pillars. The in-plan and out-of-plan mode shapes were clearly identified under ambient vibrations, in addition to the monument's natural frequencies. The dynamic parameters were estimated via the commercial software ARTeMIS using the EFDD method. Knowing that no data was available on the foundations and the soil conditions, the in-plane deformation modes provided qualitative information about the soil stiffness under the main pillars. Additionally, it was possible to correlate the damage state of the tower to a certain number of bending and torsional modes. The experimental results allowed the calibration of a numerical modal analysis elaborated on a 3D FE model, for a better assessment of the seismic capacity of the monument. The obtained dynamic parameters are to be compared to the monument response during and after a future structural rehabilitation for efficient monitoring of the structural intervention.