Introduction to the use of high-performance cement-based materials and polymer composites in new construction: material properties and behaviour, design issues, applications. Review of conventional materials and techniques for member-level and structure-level retrofit of reinforced concrete (RC) and unreinforced masonry (URM) structures. Seismic retrofit with fiber-reinforced polymers (FRP) and cement-based composites: (a) Material properties, application techniques (externally-bonded, near-surface mounted and mechanically-fastened composites), basis of design, retrofitting strategies. (b) Behaviour, mechanics and dimensioning of RC members retrofitted in flexure, shear/torsion and through-confinement. (c) Behaviour, mechanics and dimensioning of URM subjected to in-plane and out-of-plane loading. (d) Detailing, practical execution and quality control, durability. (e) Case studies and design examples.
The course introduces the basic concepts of the Finite Element Method and its application to the dynamic analysis of structures. Topics covered: Review of single degree-of-freedom systems. Basic numerical methods with applications (computation of elastic spectra). FEM formulation of the equation of motion for multi degree-of-freedom systems. Derivation of stiffness and mass matrices for 2-D and 3-D trusses, frames, and plates. Free vibrations, eigenfrequencies and eigenmodes. Assumptions involving structural damping and calculation of damping matrices. Reduction of degrees-of-freedom. Time domain analysis: Eigenmode synthesis and time stepping methodologies. Frequency domain analysis. Comparisons of different approaches, convergence and error estimates.
The course objective is to familiarize students with the elegant and powerful theory of Random Vibrations of Structural Systems (with finite degrees of freedom) with particular emphasis on the analysis of such systems to earthquake excitations.
Topics to be covered include: Theory of Random Processes [Specification of Random Processes; Stationary (Homogeneous) Random Processes; Expected Values: Moments; Differentiation and Integration of a Random Process; Spectral Representation of a Random Process; Non-stationary (evolutionary) Random Processes]. Some Important Random Processes [Gaussian, Poisson, and Markov Random Processes]. Further Properties of Random Processes [Threshold Crossings; Peak Distribution; Envelope Distribution; First-Passage Time; Maximum Value of a Random Process in a Time Interval]. Linear Structures with Single Degree of Freedom (SDOF) [System Response to Random Excitation; Weakly Stationary Excitations; Non-stationary Excitations]. Linear Structures with Multiple Degrees of Freedom (MDOF) [General Analytical Framework]. Structural Failures Resulting from Dynamic Response and Related Topics [First-Excursion Failures; Fatigue Failures]. Response of Nonlinear Structural Systems [Method of Equivalent Linearization – Hysteretic Systems].
Introduction to basic problems of soil dynamics and geotechnical earthquake engineering. Review of dynamics of simple oscillators. Wave propagation in one and multiple dimensions. Damping in soils and structures. Seismic site effects. In-situ and laboratory determination of dynamic soil properties. Foundation Vibrations. Design methods for spread footings. Dynamics of piles and pile groups. Soil-structure interaction (SSI). Beneficial and detrimental effects of SSI. Case Studies involving SSI.
The course objectives are to introduce to the students the main concepts of Earthquake Source Mechanics and Elements of the Theory of Elastic Wave Propagation (Elastodynamics) and enable them to understand modern approaches to the problem of Earthquake Strong Ground Motion Prediction and Synthesis, the ultimate objective being assessment of Seismic Hazard for earthquake engineering design.
Topics to be covered include: Earthquakes and Plate Tectonics; Seismometry; Seismic Waves – Overview; Seismic Source (Important Source Parameters; Source Spectrum; Scaling Laws); Path and Site Effects (including Basin Effects and Topography Effects) – Overview; Prediction and Simulation of Strong Ground Motion (Empirical Approaches; Mathematical Modeling Techniques -- Near-fault vs. Far-field ground motions); Seismic Hazard Assessment for Performance Based Earthquake Engineering; Relevance to Building Codes.
The presentation of the topics is tailored to the needs of earthquake engineers.
The course is intended as an introduction of graduate students to the experimental techniques and measurements used in engineering and specifically in earthquake engineering. The following topics are covered. Basic knowledge for designing an experimental campaign scope of the testing, etc. Dimensional analysis, similitude requirements, true and distorted models, scaled tests. Testing methods: static, dynamic, pseudodynamic, artificial excitation. Principles of designing test set-ups, planning and preparation. Servohydraulic testing systems: loading systems (actuators, servovalves, pumps), system control (control theory, PID control, etc). Sensors: principles of operation, sensor characteristics, sensor mounting, converters. Data collection, data acquisition (hardware and software), data analysis and presentation. Structural monitoring, in-situ artificial vibration testing. Lab exercises, example experimental studies.
The course highlights the mechanics and physical basis of non-linear behaviour of construction materials. Topics include: Review of elementary mechanics of materials, review of theory of elasticity, inelastic material behaviour (loading rate effect, temperature effect, unloading and loading reversal, multiaxial states of stress, uniaxial stress-strain curves, yield criteria), introduction to plasticity, viscoelasticity and viscoplasticity, fundamentals of fracture mechanics (mechanisms of fracture, crack propagation and stress intensity factor), fatigue of materials (progressive damage due to cyclic loading, effective stress concentration factors), time-dependent deformations (creep).
The course contents are as follows: Contribution of geotechnical engineering to earthquake engineering; Elements of engineering seismology - ground motion prediction equations (GMPE), near field effects, data for the Greek territory; Seismic site response - analytical, numerical and experimental methods; effects of site conditions (including surface topography) on ground motion; Soil liquefaction: current criteria for liquefaction susceptibility and liquefaction triggering, lateral spreading, results of experimental and numerical studies; Seismic earth pressures on retaining structures – seismic stability of slopes and dynamic bearing capacity of foundations; Dynamic soil – structure interaction; Design methodologies – design codes – performance based design – microzonation studies.
The current philosophy of force-based seismic design of buildings for controlled inelastic response and its main instruments: capacity design and detailing of plastic hinge regions for ductility. The trade-off between strength and ductility.
Conceptual design of earthquake-resistant concrete buildings. Main features and conceptual design of frame, wall or dual (frame-wall) building. Conceptual design of building foundation systems for earthquake-resistance. Case histories of buildings with deficient structural configuration in past earthquakes.
Cyclic behaviour of concrete, reinforcing bars and their interaction through bond and in interface shear transfer. Cyclic behaviour of concrete beams, columns, walls and joints: experimental results and examples from past earthquakes. Modeling of cyclic resistance and deformation capacity of concrete members in flexure, shear or flexure-shear combinations at the local and at the element level. Derivation of member detailing rules in Eurocode 8 for a target deformation capacity.
Design of foundation systems and elements in earthquake-resistant buildings.