The Structure-Soil-Structure Interaction (SSSI) phenomenon between the neighbouring structures has been interested lesser than Soil-Structure Interaction. However, in urban environments, the structures have to be constructed in the neighbourhood, and it is inevitable that these structures affect each other's responses. This study examines the Structure-Soil-Structure Interaction effects on the response of the neighbouring frame structures. In this context, firstly the effects of the consideration of the underlying soil on the response of the structures (3-, 6-and 12-storey) are compared with the fixed base conditions. Subsequently, the variation in the acceleration and basement storey drift ratios of the structures are examined to determine the effects of the presence of the neighbouring different structures. The clear distances between the structures, structure storey numbers, soil stiffness, seismic motion and layout of the structures are the parameters taken into account. Finite element method is utilised to analyse the soil and the structures subjected to seismic excitation with direct method. It is concluded that the consideration of the neighbouring structures could positively or negatively change the responses of the structures based on the dynamic characteristics of the case.

It is known that the structural health monitoring (SHM) applications rely on the physical data obtained from in-situ measurements. In this view, various instruments such as accelerometers, strain gauges, displacement sensors are used to collect data, which are to be used in structural identification applications. Considering the basic requirements like precision, accuracy and applicability for reliable data post-processing, a new scheme for a vibration sensing device is introduced in this study. The proposed sensor scheme is a vibration transducer which combines the fundamental sensing principles of conventional accelerometers and the computer vision techniques. Basically, the transducer consists of a mechanical system as the primary sensor and a camera as the secondary sensor. In conventional piezoelectric (PE) accelerometers, the PE material generates charge or voltage which is proportional to the acceleration applied to the sensor. Subsequently, this charge or voltage is measured and used to determine the imposed accelerations. However, in the proposed vibration transducer, the motion of the seismic mass is directly tracked by a camera and the displacements are extracted using computer vision algorithms. Afterwards, displacement of the seismic mass can be related to the imposed acceleration, velocity and displacement. In this study, the transducer concept was realized practically using two different primary sensors consist of a spring-mass system and a cantilever beam together with a smartphone's camera. The concept was tested on a laboratory structure in order to verify its capabilities in modal identification, damage detection and localization applications. The comparison of the results obtained by the proposed transducer and the conventional accelerometers has shown that the proposed vibration transducer is capable of both identifying modal parameters and detecting damage despite its crude design. Although the sensitivity of the transducer is lower than the conventional accelerometers in its current state, the concept is prone to further improvements.

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Pounding tuned mass dampers (PTMD), which relies on impact to dissipate vibration energy, have shown remarkable performance in suppressing structural vibrations with its modest design. However, the optimum design of PTMDs is computationally expensive due to non-smooth contact-impact behavior. This study provides a computationally efficient approach to determine the optimal parameters of single-sided PTMDs used in vibration control of structural systems. An optimization strategy is used to minimize the maximum response of the controlled structure. As is well-known, the calculation of the dynamic response of a structure could be cumbersome when conventional time-stepping techniques are used in each iteration of the optimization routine. Hence, an exact analytical solution of the steady-state vibration is used to calculate the response for different excitation frequencies, which substantially decreases the computational burden. The adopted method is computationally very inexpensive with respect to the conventional time-stepping techniques used to solve the nonlinear equations of motion to obtain response quantities. The exact solution only requires the solution of the system of five nonlinear equations in order to evaluate the steady-state response per each excitation frequency of harmonic force. A four-storey shear building is used to evaluate the optimally-tuned PTMD by the proposed procedure. In addition, simplified design equations for the coefficient of restitution and frequency ratio are provided using curve and surface fitting for preliminary design. It was shown that the effect of damping ratio of the primary structure on the optimal coefficient of restitution value is not considerable, while it has significant influence on the optimal frequency ratio. It was also realized that the objective function used in optimum parameter design has only one local optimum, which is suitable for the application of gradient-based optimization methods.

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