Infrastructural assets such as roads, bridges, and buildings make a considerable contribution to national economies. These assets deteriorate due to aging, environmental conditions, and other external factors. Maintaining the performance of an asset in line with rational repair strategies represents a considerable challenge for decision-makers, who may not pay attention to developing adequate maintenance plans or leave the assets unmaintained. Worldwide, organizations are under pressure to ensure the sustainability of their assets. Such organizations may burden their treasury with random maintenance operations, especially with a limited budget. This research aims to develop a generalized condition assessment approach to monitor and evaluate existing facility elements. The proposed approach represents a methodology to determine the element condition index (CI). The methodology is reinforced with an artificial neural network (ANN) model to predict the element deterioration. The performance of this model was evaluated by comparing the obtained predicted CIs with ordinary least squares (OLS) regression model results to choose the most accurate prediction technique. A case study was applied to a group of wooden doors. The ANN model showed reliable results with R² values of 0.99, 0.98, and 0.99 for training, cross-validation, and testing sets, respectively. In contrast, the OLS model R² value was 1.00. These results show the high prediction capability of both models with an advantage to the OLS model. Applying this approach to different elements can help decision-makers develop a preventive maintenance schedule and provide the necessary funds.

Special structures such as bridges, nuclear and power plants, etc, have unique importance. These strategic structures age and degrade with time. Previously, visual inspection was the main tool for following such structures' degradation. Recently, Structural Health Monitoring (SHM) is used by the industry as a viable technique to obtain continuous realtime data about the safety and serviceability of vital structures. Moreover, measuring electrical resistivity is a low cost, simple, efficient method that has received recent attention in terms of SHM. The objective of this study is to use electrical resistivity measurements in SHM of Reinforced Concrete (RC) beams. An experimental program is conducted to study the effect of crack initiation and propagation in RC beams on Inner Electrical Resistivity Measurements (IERM) when beams are loaded by the three-point bending test. The results show that the technique is effective in detecting cracks and can be extended to global SHM of RC structures.

The contemporary world is reaching a point of having to look back carefully to reevaluate the damage that has been done to Mother Nature. The increasing pollution and contamination have gotten far beyond safe margins. In contrast, the need for energy is currently escalating. Meanwhile, traditional energy resources like petrol are not only adding to pollution but even are getting consumed and expected to be scarce within decades. Consequently, nations worldwide have realized the common goal of searching for new clean renewable energy resources. It is a matter of time that these renewable energy sources will prevail and become the main sources. The most effective resource of renewable energies is wind. This is attributed to consistent availability in many spots worldwide. Offshore areas may be the best for higher wind momentum. Besides, the escalating land prices redirected experts to vast offshore areas. On putting economic costs into account, an optimized design is thus required to minimize the cost of offshore wind farms together with considering efficiency. Wind turbines can be classified according to number of rotors, Single-Rotor Wind Turbine (SRWT) and Multi-Rotors Wind Turbine (MRWT). This paper compares from a stability-wise scope between existing models of offshore SRWT and MRWT, both with total capacity of 5MW using ANSYS software. Both turbines are considered subjected to similar conditions of wind and wave loads. On studying the stability of the two types together with accounting for costs and investigating comparable loads during storms with extreme conditions, it is shown that MRWT are locally subjected to higher deflections in the rotor fixation spars. However, MRWT could be cheaper as well as easier for transportation. This paper suggests using additional bracing between spars for optimum performance of MRWT and thereby optimum design of wind farms.

Choosing the suitable infrastructure system is becoming more challenging with the increase in demand for heavier structures contemporarily. This is the case where piled raft foundations have been widely used around the world to support heavy structures without extensive settlement. In the latter system, piles are rigidly connected to the raft, and part of the load goes to the soil layer on which the piles are bearing. In spite of that, when soil profiles contain thicker soft clay layers near the surface, or at relatively shallow depths, it is unfavorable to use the rigid piled raft foundation system. Consequently, the disconnected piled raft system was introduced as an alternative approach for the rigidly connected system. In this system, piles are disconnected from the raft using a cushion of soil, mostly of a granular interlayer. The cushion is used to redistribute the stresses among the piles and the subsoil. Piles are also used to stiffen the subsoil, and by this way reduce the settlement without being rigidly connected to the raft. However, the seismic loading effect on such disconnected foundation systems remains a problem, since the soil profiles may include thick clay layers which raise risks of amplification of the dynamic earthquake loads. In this paper, the effects of seismic behavior on the connected and disconnected piled raft systems are studied through a numerical model using Midas GTS NX software. The study concerns the soil-structure interaction and the expected behavior of the systems. Advantages and disadvantages of each foundation approach are studied and a comparison between the results are presented to show the effects of using disconnected piled raft systems in highly seismic zones. This was done by showing the excitation amplification in each of the foundation systems. Keywords: Soil-Structure Interaction, Disconnected Piled Raft, Risks, Seismic Zones.