Quasi-Static Nonlinear Seismic Assessment of a Fourth Century A.D. Roman Aqueduct in Istanbul, Turkey

Abstract

The majority of architectural heritage consists of load-bearing masonry components made up of stone units and relatively weak mortar joints, yielding potential weak planes for masonry structures where tension and shear failures are expected to occur. Advanced nonlinear analyses are required to simulate these phenomena and predict the corresponding nonlinear structural behavior of historic masonry constructions. In this context, this paper presents a model of a stone masonry Roman aqueduct (the Valens Aqueduct), constructed in the fourth century A.D. in Istanbul, Turkey, to explore the seismic capacity and behavior using the discrete element method (DEM). The employed modeling approach comprises distinct rigid blocks interacting along their boundaries based on the point-contact hypothesis. Thus, the discontinuous stone skeleton of the masonry aqueduct is represented explicitly in the computational model. First, a validation study was conducted on the laboratory experiment to demonstrate the capabilities of the adopted modeling approach. Then, a discontinuum model representing the Valens Aqueduct was used to assess the seismic capacity of the structure under gradually increasing lateral forces. The numerical simulations gave insight into the structural response of the aqueduct from the elastic range to total collapse. Additionally, parametric research was performed considering joint properties, namely the joint tensile strength, contact stiffness, joint friction angle, and compressive strength of the masonry, to quantify the effects of contact parameters on the displacement response of the DEM model. Further inferences were made regarding the modeling parameters, and practical conclusions were derived.

Static and Impact Response of a Single-Span Stone Masonry Arch

“…The explained calculations are executed in an explicit dynamic scheme both for static and dynamic analysis. It is also worth mentioning that quasistatic solutions are obtained by adopting Cundall's local damping formulation [9,30], whereas Rayleigh damping (consisting of mass and stiffness proportions) is used for the dynamic analysis [31,32]. Moreover, the common-plane approach is utilized to trace and recognize new contact points during the analysis, which is essential for impact simulations [33].…”

Numerical Prediction of the Seismic Behavior of Reassembled Columns in Ancient Structures: An Anastylosis Model for the Temple of Apollo Pythios in Gortyn (Crete)

“…In particular, DEM has been largely used in the simulation of stone block masonry [20,21]. Application to historic [22] and archaeological [23,24] structures has also proved to be effective in the seismic simulation of ancient remains.…”

Dynamic Damage Mechanism and Seismic Fragility Analysis of an Aqueduct Structure

“…The aqueduct is a water conveyance structure commonly used for irrigation, water transfer, and supply in water conservancy projects. The construction of the aqueduct structure can not only alleviate the severe water shortage disaster for human beings, but also contributes to the local economic, science and technology, and social development, achieving the main sustainable development goals (SDG) that are employed by the United Nations (UN) Agenda, such as the Valens Aqueduct (Turkey) [1]. The structural type of aqueduct is mainly divided into rectangular, semicircular, U-shaped, and so on [2,3].…”