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The classical bending theory of elastic plates is based upon the assumption that the internal moments are proportional to the curvatures of the median deformed surface. This theory does not include the effects of shear and normal pressure in the plate. The model of a bi-modulus foundation is a realistic generalization of the Winkler’s classical one and is widely used to represent the subgrade of railroad systems, airport lanes [1], [2]. The derived equation of elastic thick plates on bi-modulus foundation considers shear and normal stress as linear variable across the plate thickness. This paper presents numerical solutions for thick plate resting on bi-modulus subgrade. These solutions take into account the shear distortion, and they are compared to the solution obtained by Finite Element Analysis and with the Winkler’s model. Particular solutions for the rectangular plate of clamped boundary, for the hinged rectangular plate and for a semi-elliptical plate, are discussed. The numerical solutions consist of double power series and they were obtained based on the minimum of the total strain energy [1]. Parametric studies have been performed in order to emphasize the effects of the chosen foundation and that of the geometry.

This paper tries a compact presentation of experimental research of engine-foundations. The dynamic phenomena are so complex, that the vibrations cannot be estimated in the design stage. The design engineer of an engine foundation must foresee through a dynamic analysis of the vibrations, those measures that lead to the avoidance or limiting of the bad effects caused by the vibrations.

Unreinforced masonry (URM) is considered one of the oldest construction materials being until the end of XIXth century, the basic material for: foundations, walls, columns, volts, staircases, floor joints, roofs, retaining walls, drainage channels, barrages, etc. Construction with URM elements posses a series of advantages such as: fire resistance, thermal an acoustic insulations between interior and outside spaces, humidity resistance. However the URM elements have some significant inconveniences such as: large self weight (heaviness causes cracks in the other elements of structures), reduced mechanical strengths in comparison with other traditional materials (steel and concrete), low tenacity, great manual labor consumptions, and vulnerability to earthquakes. Various factors cause deteriorations which must be overcome by strengthening solutions. Some strengthening solutions based on fiber reinforced polymers (FRP) products applied directly on URM brick walls are presented in the paper.

The reinforcement of structural wood products has become in the last decades an efficient method of improving structural capabilities of load carrying members made of this material. Some important steps in earlier stages of research were focused on using metallic reinforcement, including steel bars, prestressed stranded cables, and bonded steel and aluminum plates. A disadvantage of the metallic reinforcement was the poor compatibility between the wood and the reinforcing materials. In comparison with metallic reinforcement, fiber reinforced polymers (FRP) composites are compatible with structural wood products leading to efficient hybrid members. Some interesting strengthening alternatives using FRP applied to wood beams and to wood columns are presented in this paper.

The paper presents the experimental program developed in the Laboratory of Civil Engineering Faculty of the ”Politehnica” University of Timișoara, Romania, in order to establish the real behavior of bolted connections in cold formed steel trusses. First, the semi-rigid behavior of cold formed steel truss joints is demonstrated by means of test of typical T joints. A formula for the axial rigidity of single lap joint is determined, and, based on this formula, theoretical models are proposed for the rotational rigidity of cold formed steel truss bolted joints. In the third step of the experimental program, a cold formed steel truss is tested, in order to observe the structural behavior of joints and to validate the theoretical assumptions. A numerical analysis of the tested structure is also performed, and comparisons with the experimental results are given.

The main interest of this paper generally refers to the results of an analysis regarding the influences of the tartar deposits effect on the water supply plumbing systems (mainly warm water installations made of steel pipes or polar plastic materials). The dysfunctional effect due to this effect has a consequence the increase of the linear pressure loss and the decrease of the service pressure of the consumers. To emphasize the effect of the tartar impurity deposit of the time behavior for the sanitary plumbing systems, the analysis was made using the MATLAB program facilities for the simulation of this phenomenon. The model allows several propositions to include the impurities deposit effect in the standard method to design the installations.

The actual trend of performance based modelling of the seismic action is to adopt probabilistic models of the seismic hazard. In the first part of the paper are presented theoretical aspects of the seismic hazard definition from the probabilistic point of view as „a function P(Y > y) that describes the probability that in a given region (M) and for a time interval (T), the value of a parameter, Y (for example: macroseismic intensity, acceleration, velocity and displacement of the soil) to overpass the given value (y) as an effect of a seismic event” [4]. The probabilistic study of the seismic hazard gives the possibility to implement new parameters, such as: the likeliness and the occurrence frequency of the seismic events. Nowadays most of the international standards adopted the probabilistic analysis of the seismic hazard as a complementarity of the deterministic analysis. In the second part of the paper are presented the results of the probabilistic analysis for Vrancea region using the Gumbel 1 probabilitic model that has the parameters determined throughout the extreme values statistical method.

Retaining walls are large category of engineering structures of multiple uses, having an essential safety ensuring role. The structural systems are varied because the situations and requirements derived from both site conditions and other criteria are varied. The paper enlarges upon retaining walls systems that use an outstanding amount of precast units and multiple cylindrical vault type structural systems supported by abutments [1], [2]. The paper proposes extending the structural system to retaining walls and develops certain specific issues. Some considerations regarding structural design are made.

In the recent years many techniques has been developed to reduce the vibration response in civil structure, such as tall buildings and long bridges. Attention of this paper is focused on the difference among passive, active and semi-active control systems. If passive control systems are used enhancing structural damping, stiffness or strength, the other control techniques employ controllable forces to add or dissipate, or both, energy in a structure due to the specific devices integrated with sensors, controllers and real-time processes to operating. Some applications will be proposed and applied to single degree of freedom systems in vertical working conditions.

The Structural Dynamics involves a large amount of computational effort. Most dynamic structural models require the solution of a set of 2nd order differential equations. There are developed integration techniques for the 1st order and 2nd order differential equation. The 2nd order set of equations is submitted to a transformation [12] in order to obtain the first order system. This paper deals with the “stiff” systems of 1st order differential equations. From the physical point of view the stiff system consists of two components – one with a fast dynamic behavior and other one, slow. The ignoring of high frequency component may lead the wrong results. There are presented some advanced solution methods, criteria for choosing the appropriate techniques and a case study.

Homogeneity is a general concept often used in science and mainly engineering as a work hypothesis with essential implications in the expression of some rules. From a mechanical viewpoint, the features of a material are expressed by the characteristics that define them, the latter being determinate by the chemical and physical features of the constituent material. In this paper is used the entropy concept defined in the information theory, on which basis are defined the notions of degree of homogeneity and homogeneity factor. With means of these sizes different statistics populations can be analysed. Particularly it refers to the elasticity moduli of the steel. For example have been considered the two statistics series representing the elasticity moduli obtained by testing some steel square tubular bars.

Over the past three decades, a great interest has been generated by the use of protection systems to mitigate the effects of dynamic environmental hazards on civil engineering structures, such as earthquakes and strong wind. These control systems develop controllable forces to add or dissipate energy in a structure, or both, due to specific devices integrated with sensors, controllers and real – time process to operate. The paper includes the advantages of these technologies consisting of the following sections: 1 represents an introduction, 2 deals with passive control system, 3 regards some control techniques, 4 concerns hybrid control techniques, 5 contains semi – active control techniques, and 6 is dedicated to general conclusions.

The paper reviews some equivalent viscous damping models used in the displacement based seismic design considering the equivalent linearization. The limits of application of the models are highlighted, based on comparison existing in the literature. The study is part of research developed by author, aimed to determine the equivalent linear parameters in order to predict the maximum displacement response for earthquakes compatible with given response spectra.

The paper proposes some formulae to determine the equivalent linear parameters for spectral earthquake response of SDOF non-linear systems. The proposed formulae for the equivalent viscous damping and equivalent period are valid for the elasto-plastic hysteretic model and for earthquakes compatible with Eurocode 8 response spectra. This study is part of a research aimed to determine the equivalent linear parameters in order to predict the maximum displacement response for earthquake compatible with given response spectra, for different hysteretic models.

The author’s experimental researches presented in this paper were focused on the building materials obtained by using ultra-fine fly ash and silica fume (like heavy mortars or compacted lightweight concretes). From experimental determinations there have been studied the following characteristics: the water absorption in function of mass, apparent density, tensile and compression strength (at 7 and 28 days), technical efficiency at 28 days and shrinkage.

In this paper the authors present information about the Self-Compacting Concrete and experimental results regarding the use of them into precast element industry. This type of concrete does not require vibration for placing and compaction; it is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. The experimental programme has take into account two prestressed beams which were prefabricated and tested on a special stands. The beams of Self-Compacting Concrete with the length of 24 m were prepared at „Beton-Star” Kft, Kecsekenet, Hungary, and used at the CASCO, Satu-Mare.

The paper aims to establish a series of methods regarding the dimensioning of the main economic parameters specific to the accomplishment of a building design, parameters generally linked to the total cost of the project. The total realization cost of a construction project represents the money expression of all “efforts” (labor force, material resources, equipment and technological units, informational resources, services, taxes, technical-administrative actions, etc.) necessary for the realization of the project in all its constitutive stages.

An ageing and deteriorating bridge stock presents the bridge owners with the growing challenge of maintaining the structures at a satisfactory level of safety, performance and aesthetic appearance within the allocated budgets. This task calls for optimized bridge management based on efficient methods of selecting technical and economical optimal maintenance and rehabilitation strategies. One of the crucial points in the assessment of the current condition and future development and performance. Selecting the optimal maintenance and rehabilitation strategy within the actual budget is a key point in bridge management for which an accurate assessment of performance and deterioration rate is necessary. For this assessment, the use of integrated monitoring system has several advantages compared to the traditional approach of scattered visual inspections combined with occasional on site testing with portable equipment and laboratory testing of collected samples. For this reason, attention is more focusing on the development of permanent integrated monitoring system for durability assessment of concrete bridges. It is estimated that with the implementation of such integrated monitoring systems, it should be possible to reduce the operating costs of inspections and maintenance by 25% and the operator of the structures will be able to take protective actions before damaging processes start. This paper indentifies the main bridge owner requirements to integrated monitoring systems and outlines how monitoring systems may be used for performance and deterioration rate assessment to establish a better basis for selecting the optimal maintenance and rehabilitation strategy.

Integral bridges, or integral abutment and jointless bridges, as they are more commonly known in the USA, are constructed without any movement joints between spans or between spans and abutments. Typically these bridges have stub-type abutments supported on piles and continuous bridge deck from one embankment to the other. Foundations are usually designed to be small and flexible to facilitate horizontal movement or rocking of the support. Integrally bridges are simple or multiple span ones that have their superstructure cast integrally with their substructure. The jointless bridges cost less to construct and require less maintenance then equivalent bridges with expansion joints. Integral bridges present a challenge for load distribution calculations because the bridge deck, piers, abutments, embankments and soil must all be considered as single compliant system. This paper presents some of the important features of integral abutment and jointless bridge design and some guidelines to achieve improved design. The goal of this paper is to enhance the awareness among the engineering community to use integral abutment and jointless bridges in Romania.

This paper presents the lab results for four types of filler used in producing the asphalt mixture in Romania, as well as other physical-chemical characteristics of a new type of filler, derivate of the grinding of the bituminous shists through a ball mill/crusher. Knowing these physical-chemical characteristics is crucial for asphalt mixtures due to the complex purpose of the filler.

A model to determine the time till first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts that recognizes and incorporates the statistical nature of factors affecting the corrosion process, consists of the following serial phases: diffusion to the depth of the steel that would precipitate first maintenance actions; corrosion of the steel at the first maintenance depth until cracking and spalling occurs; continuous spalling until a damage level is reached which is defined as the end of functional service life for the deck of concrete bridge. The model expands on an existing deterministic model using statistical computing techniques, including resampling techniques such as the parametric and simple bootstrap. Emphasis was placed on the diffusion portion of the diffusion-cracking model, but advances can be readily included for the time for corrosion deterioration after corrosion initiation. The diffusion phase is described by Fick’s law and the boundary conditions define the solution form. The time till cracking model depends upon some factors as concrete strength properties, cover depth and corrosion rate. Corrosion rate has a significant influence on the time to cracking which typically occurs in three to seven years after initiation. Service life model that predict the time to first repair and rehabilitation of concrete bridge decks provide a useful tool for comparing the effectiveness measures and provide bridge engineers with a useful planning tool. A service life model for the corrosion of concrete bridge deck in chloride laden environments is proposed. The aim of this paper is to enhance the awareness among the engineering community to use the model to determine the time till first repair and subsequent rehabilitation of concrete bridge decks exposed to chloride deicer salts in Romania.

Although the Winkler’s model is a poor representation of the many practical subgrade or subbase materials, it is widely used in soil-structure problems for almost one and a half century. The foundations represented by Winkler model can not sustain shear stresses, and hence discontinuity of adjacent spring displacements can occur. This is the prime shortcoming of this foundation model which in practical applications may result in significant inaccuracies in the evaluated structural response. In order to overcome these problem many researchers have been proposed various mechanical foundation models considering interaction with the surroundings. Among them we shall mention the class of two-parameter foundations -- named like this because they have the second parameter which introduces interactions between adjacent springs, in addition to the first parameter from the ordinary Winkler’s model. This class of models includes Filonenko-Borodich, Pasternak, generalized, and Vlasov foundations. Mathematically, the equations to describe the reaction of the two-parameter foundations arc equilibrium ones, and the only difference is the definition of the parameters. For the convenience of discussion, the Pasternak foundation is adopted in present paper. In order to analyse the bending behavior of a Euler-Bernoulli beam resting on two-parameter elastic foundation a (displacement) Finite Element (FE) formulation, based on the cubic displacement function of the governing differential equation, is introduced. The resulting effects of shear stiffness of the Pasternak model on the mechanical quantities are discussed in comparison with those of the Winkler’s model. Some numerical case studies illustrate the accuracy of the formulation and the importance of the soil shearing effect in the vertical direction, associated with continuous elastic foundation.

The present paper approaches of plates subjected to transverse loads, when the shear force and the actual boundary conditions are considered, by using the Finite Element Method. The isoparametric finite elements create real facilities in formulating the problems and great possibilities in creating adequate computer programs.

Evaluating the risk of natural disasters is an intensely debated issue, both on national and international level. In the present paper, after a brief review of the international research in this field and an introduction in risk management, we insisted on risk analysis of an urban area, called urban system. More precisely, we investigated the evaluation of risk and the behavior of the pipelines infrastructure characteristic in an urban area during an earthquake.By taking into account a certain region in Jassy city area, we present a methodology of evaluating seismic risk of the utilities network of the region. The method consists in establishing the necessary steps to be taken in such an evaluation. These steps are also graphically displayed for the gas pipelines of the area, and emphasizing the critical points existent in that sector e.g. gas stations). Using the cellular automata technique, inspired from the artificial intelligence and complex system fields, based on the GIS map of the analysed region, we obtained a map with the risk areas in case of an earthquake, taking into account the gas pipelines network and the existing critical points.

The results and conclusions regarding the experimental test of the joint assembly of thin walled steel profile with and without strengthening elements (stiffeners) are presented. The entire test series have been performed using the 5 mm thick KB600 thin-walled profiles and 3.5 mm thick KB450. In the paper will be presented the analysis of the joints connecting the KB600-5.5 steel profiles. The KONTIBEAM system is primarily made of two galvanized sheet profiles so denominated as KB, which are joined by means of steel sheets (usually of 10mm thickness), placed in between them. Connecting of this assembly (KB’s and connectors) is realized by using M20 bolts put in φ22 holes, which work in friction with two contact planes. The tested joints are connected by means of 8.8 class HSFG bolts (High Strength Friction Grip). The main conclusions of the tests are that the contour bolted connections assure a good behavior between the KB profiles and the joint element. Due to their position the strengthening elements lead to an increase of the bearing capacity up to 30…35%with respect to the yield limit of the KB material. The use of such strengthening elements allows the optimum use of the KB profiles, thus leading to the reduction of the material consumption.

The paper is structured in three main parts. In the first part, there is a classification of the critical systems existing in the urban background, which are part of an extremely urging informational infrastructure in case of a seismic event. The critical systems are identified as those systems whose malfunction may lead to disasters affecting the human being and the environment as well. The second part focuses on the underground pipe networks, presenting at the same time, their classification into three categories of great importance in case of an earthquake, and last but not least, the final part contains the presentation of an analysis methodology of seismic behavior of the underground pipe networks, considered as part of the existing critical systems, in case of a seismic event in an urban area.

In the first part of the paper there shall be considerations on the hypothesis and possibilities of assessing the fire resistance of the steel structural elements. After the critical presentation and analysis of the breaking criteria used regarding structures’ calculations at high temperatures, the way of determining the fire resistance of a metal beam stressed at pure bending is presented.

The technique of externally bonding fibre reinforced polymer (FRP) composite laminates on the tension side of reinforced concrete (RC) beams is already widely accepted as an easy to apply, corrosion resistant and effective solution due to the high strength as well as the low weight of the composite material. The basalt fibres are produced from volcano rocks by a simple process; their applicability as reinforcing material composites utilized for plate bonding of RC beams was not enough researched up to now but it seems to be a cost-effective, durable and fire resistant alternative to traditional fibres. High basalt fiber’s advantages, related to physical-mechanical characteristics and cost, stipulate a new high efficient structural composite materials, which can replace asbestos, metal, timber, plastic materials, etc. The paper investigates the applicability of externally bonded Basalt Fibre Reinforced Polymer (BFRP) laminates in strengthening of rectangular reinforced section of a RC beam. The influence of the cross-sectional BFRP area on service and ultimate bending moments and also on service deflection, are analysed. The procedure is based on section analysis, equilibrium of forces and compatibility of strains, considered appropriate for any type of fibres, in case of rectangular RC beams.

Traditional steel based reinforcement systems for concrete elements are facing with serious problems mainly caused by corrosion due to chemically aggressive environments and salts used in deicing procedures, especially in case of bridge steel reinforced concrete girders. Also in some cases special applications require structural members with magnetic transparency. An alternative to this major problem has recently become the use of fiber reinforced polymer (FPR) composite bars as internal reinforcement for concrete beams. The particularities of their mechanical properties are making the design process a difficult task for engineers, numerous research centers being involved in correcting this situation. The general aspects concerning the conceiving of FR.P reinforced concrete beams are firstly analyzed, compared to those reinforced with steel bars. Some results of a Finite Element Analysis, as part of a complex program which also implies full scale testing of FRP reinforced beams subjected to bending, are given and discussed in the paper. The low elasticity modulus presented by glass fiber reinforced polymer (GFRP) bars does not justify its use from structural point of view when deflection is the limiting condition but for corrosive resistance reasons and special electromagnetic properties this system can be promoted.

The aim of this paper is to propose an original optimization approach using the concept of computational design of experiments and response surface methodology to check the curvature in numerical experiments. Generally, for the study of the strongly nonlinear phenomena, it is recommended to use a second-order model. This paper proposes a new technique to estimate a quadratic effect for a model based on finite element simulations and the Design of Experiments. Therefore, it is very important that the proposed technique (adding center points) controls other properties of the design matrix, especially orthogo¬nality for the response surface methodology and brings more information for the quality of the proposed model. The computational design of experiments is considered an advantage in comparison with design of physical experiments because generally computer solutions cost less than physical testing. The bending process optimization is used to improve the performances of this approach.

In sanitary systems assembly, domestic hot water distribution supply networks represent an important weight for energetically balance.par This paper presents, in an analytical and graphical manner, the computational tools needed for domestic hot water piping system behavior characterization in different functional and structural assumptions.

The paper presents the results from tests on clay brick masonry walls strengthened using fiber reinforced polymer (FRP) composites. Five 1.50x1.50 m wall specimens have been subjected to pure in plan shear loads up to failure and then retrofitted on one side, with different types, percentages and lay-ups of the fiber sheets. Based on the experi¬mental results, it was proven the effectiveness of using externally bonded composites for retrofitting brick masonry walls, with less disruption during strengthening, and in this way with reduced costs compared with other conventional repairing and strengthening tech¬niques. Performances of the different strengthening configurations were compared in terms of ultimate load, strain in composite and failure mechanism.

Between structure, infrastructure (foundation) and soil there is an effective interaction, which has to be taken into account as correctly as possible every time we do the calculation. This effective interaction can be analysed in a global form, considering on one hand the entire building, and on the other hand the soil -- establishment surface, or in an analytical form: we consider first the soil -- infrastructure (foundation) interaction and then the structure -- infrastructure one. Without considering the interaction, we cannot make neither the calculation (for the soil) according to the limiting deformation state which has to be compatible with the structure’s resistance system, nor calculation for the limiting resistance state, because the correct distribution of efforts along the contact surface between the soil and the structure is unknown, so we cannot determine the zones of plastical equilibrium in the soil massive and the conditions of limited equilibrium. Also, without considering the infrastructure, we cannot correctly calculate the efforts and the deformations which may occur in all resistance elements of the building. Therefore, we cannot talk about limiting state calculation without considering the interaction between the soil and the structure itself. The problem of interaction between building, on one hand and soil foundation, on the other hand, is not approached very much in the specialized literature, because of the big difficulties raised by summarizing all the factors that describe the structure and the environment, which would be more accessible to a practical calculation. A lot of buildings or elements of buildings standing on the soil or on another environment with finite rigidity can be taken into account as beams supported on a straining environment, (continuous foundations, resistance walls, longitudinal and transversal membranes of civil and industrial buildings, hydrotechnic works). Therefore, in the present paper we shall analyse the problems regarding the calculation of some types of beams supported on a straining environment (foundation soil). In general, we shall use the term “beams supported on a straining environment” and not “beams supported on an elastic environment” because the foundation soil, which is in fact the supporting environment most commonly met in practice, cannot be considered as a perfectly elastic, homogeneous and isotropic environment, and it can be at most simplified in calculation as a linear or not linear environment.

Romanian higher education began a long time ago, having its own national specificity but being also influenced by the education from other developed countries. Between 1813 -- 1840 Gh. Asachi created the School of Terminal Engineering, establi-shing the foundations of the Technical Engineering University. In Moldavia, higher education in engineering, in the field of roads and bridges, coincides with the official opening of the Faculty of Construction of Jassy, in 1941, as part of the Polytechnic Institute, today the „Gheorghe Asachi” Technical University. Over the years, this type of education has evolved and developed, under the influence of schools of engineering such as The School of Bridges and Roads in France. The French School of Bridges and Roads was created by a decree of the king, on the 14th of February 1747. In two and a half centuries, it has trained about 15,000 engineers, who accomplished great works both in their native country and abroad. The reputation of this school is based especially on the discoveries, the accomplishments and the activity of these engineers, who have a great impact on the development of this institution. Most of these engineers did not go down in history (we seldom know the name of the person who built a bridge or a road). We remember some of them by a formula, a machine, a plate on a road, without actually knowing who is the person behind the name. Shaping their portraits, we could bring them back to the memory of the public, emphasizing the common aspects of their professional training at the School of Bridges and Roads. A free professional background, of a high scientific level, comprising a lot of practical issues, based on public transport in the beginning, where reflection and action play an important part. Except a lot of great scientists (among them, a Nobel prize laureate), inventors, entrepreneurs, engineers with prestigious accomplishments, there are also politicians (even a president), writers, a navigator. The selection of these personalities was difficult and can be contested. It was not intented to establish a hierarchy, but only to create a gallery of portraits, the only criterion taken into account being the exclusion of those engineers who are still alive. Unfortunately, there is no woman among these portraits, because their access was only permitted in 1959 for civil engineers and in 1975 for the others. We hope that this anomaly will be redressed in the paper celebrating 300 years of existence of this school. After a quarter of a millennium, in the 21st century, the oldest civil school of engineers in the world, created during the reign of Louis XV, remains what it has always been: a way of modern training in the benefit of the nation and of society, having the ambition to instruct a quality personnel, able to adapt to the problems and needs of its epoch. With a prestigious heritage, the School of Bridges and Roads has evolved and transformed during its 250 years of existence, always remaining proud of its past and at the same time open towards the future. Many authors have already mentioned the history, rich in events, of this institution. We shall try to describe it concisely in the present paper. We shall present some portaits of well-known engineers: great constructors, inventors, scientists, making themselves known in other areas than their initial training, they illustrate a less known aspect of the life of the roads and bridges engineer, a rich, intense, varied life and activity. The objective of this paper is to allow a better understanding of what has been, over the past 250 years, the french School of Roads and Bridges.

During the last few years, it has been paid a considerable attention to the searching and developing of some procedures and mechanisms of structural control to mitigate the effects of dynamic environmental hazards on civil engineering structures. In this paper we review some full-scale applications of semi-active control systems for the protection of the civil structures under dynamic actions.

Masonry represents one of the earliest structural materials used by mankind. A lot of the ancient building structures were made using masonry. A large number of these buildings have been stated historical monuments. Most commonly masonry elements which are able to cover large spans was masonry arches. The paper makes a detailed presentation on structural behaviour and failure mechanisms of a horizontally loaded masonry arch. The arch model was built at a 1 : 1 scale using solid bricks and M10Z mortar. It was firstly loaded with vertically acting dead loads and with horizontal load acting in its plane. In this loading hypothesis, a plastic hinge occurred leading to the failure of the arch and loss of load bearing capacity. In the next stage of the experimental program, the arch was strengthened using a composite material membrane at the upper face. The membrane consisted in a continuous, glass-fiber fabric and epoxy resin. After proper curing, the same loading hypothesis was used. The failure mechanisms changed and a larger horizontal loading level was noticed. Further on, the arch was rehabilitated using a different composite material layout, the membrane was applied both on upper and bottom faces as well as partially on the lateral faces of the arch. This new rehabilitation layout leads to a significant increase in the load bearing capacity of the arch. The failure mechanisms were changed causing a significantly better overall structural behaviour of the arch.

While the overall goal is to prevent disasters as much as possible, the goal of mitigation is to reduce the risks. That is why the risk must be quantifiable in the decision support system. Geographic Informations System (GIS) support may be used for all the disaster prevention phases, but what we are concerned with here is the use of GIS for physical planning in the mitigation phase. In this paper we present a methodology and several case studies of using GIS as a tool for awareness and mitigation of seismic effects of possible future events in the urban area.

The interpretation, using methodological elements developed in INCERC, of data of instrumental nature obtained in Jassy during the 1986 and 1990 Vrancea earthquakes, is the main goal of the paper. The response spectra (for 12 azimuthally equidistant horizontal directions) of strong motion records, the global parameters which characterize an individual (horizontal) component of a record (effective peak values and corner (control) periods), and the instrumental intensity (global and averaged upon a frequency interval, based on destructiveness spectrum and on response spectrum) are the main numerical results obtained for the seismic records at hand. Finally, an evaluation of results, as well as conclusions useful for the aseismic design of buildings in Jassy, is presented.

The application of control systems to civil engineering structures has been investigated in recent years to demonstrate the efficiency of these systems during exceptional natural events such as earthquakes and severe winds. In this paper, a review of some full-scale implementations of active and hybrid control systems for the protection of the civil structures to dynamic actions is performed.

Damage detection in civil engineering structures using changes in measured modal parameters is an area of research that has received notable attention in literature in recent years. This paper compares two different experimental techniques for predicting damage location and severity: the Change in Mode Shapes Method and the Mode Shapes Curvature Method. The comparison is established with reference to a simply supported finite element bridge model in which damage is simulated by reducing opportunely the flexural stiffness, $EI$. The results of this study indicate that change in modal curvature is a significant damage indicator, while indexes like MAC and COMAC--widely right for FE model updating--lose their usefulness in order to damage detection.

This paper presents a GIS-based methodology for monitoring the seismic performance, while taking into account the deteriorations revealed during GIS-based scenarios aiming at the identification of the seismic serviceability of the structure. By applying the geographical information system (GIS) containing geo-spatial data, one can develop useful scenarios to improve the knowledge of structural vulnerability of the urban built infrastructure. Scenarios of modelling, simulation and non-linear seismic analysis are described and applied to a class of damaged models for some of the structures typical of the existing urban infrastructure of Jassy, Romania. The management of GIS-based seismic vulnerability of existing concrete structure is presented as a tool for awareness and mitigation of seismic effects of possible future events in the urban area.

The structural arrangement of sandwich panels with foam core and corrugated faces offers unique opportunities to mix and tailor materials and cross-section proportions to meet structural design criteria. For cost effective design, economic comparisons between combinations of different materials in sandwich structures must be made. Such comparisons should be based on sandwich proportions that vary for each combination of materials and that reflect the minimum combined cost of the core and facings. Simplified relations which can be used for economic analysis are proposed in the paper.

The paper describes a calculus procedure to determine the elastic--plastic rotation capacity of steel structural members. The rotation capacity calculus is very important for the design of steel structures exposed to seismic action. The calculus procedure is based on the equivalent elastic--plastic bending moment. This calculus procedure was applied on two types of structural members (beams, columns).

Finite element method was developed to be applied in case of the elastic materials. If this method is applied on reinforced concrete elements and structures, the results are affected by errors because this material doesn’t have an elastic behavior on loads. Because the reinforced concrete has cracks in service, the evaluation of reinforced concrete structures with finite element method requires some improvement of the method to obtain the results without errors. The paper presents a special type of finite element who can describe, with mathematical relations, the behavior of the reinforced concrete.

The aim of this paper is to present an approach for developing material models, using a statistical investigation, for analysing the mechanical characteristics of polymer concrete. The experimental studies were realized on polymer concrete prepared of epoxy resin, silica fume and aggregates. The mix combinations were designed based on the mixture design of experiments concept. For each polymer concrete combination the mechanical properties were studied. The results are reported for polymer concrete realized of epoxy resin and silica fume (SUF) as filler using Response Surface Methodology (RSM). The effect of each variable on the response was analysed by this advanced method adapted on the study.

In the western part of Romania, on the highway still are in operation, after two World Wars and other events, some old highway bridges erected on the beginning of the last century. Some of these structures are witnesses of the past, representing technical monuments with emblematic character. The duty of the administation is to maintain these structures in service. The paper presents an overview on the evaluation methodology of the remaining service life on the bases of the new principles. The procedure to establish safe inspection intervals is also pointed out.

The paper presents the characteristics of existing structures under extreme actions, general and specific rehabilitation solutions detailed for reinforced concrete and masonry structures. Rehabilitation of different types of existing structures are described: a reinforced concrete framed structure presenting major detailing vulnerabilities at seismic actions; an apartment house affected by an explosion; two masonry buildings affected by a recent earthquake.

The present paper proposes the analysis of the efficiency of water to air heat exchanger with heat pipes for the mechanical ventilation system. The performed study is based on the necessity of the unconventional energy forms capitalization, increasing of the energy efficiency and the energy consumption decrease in concordance with the sustainable development concept.

Under the conditions of present society in which providing an optimum interior comfort is confronted with the necessity of the energy consumption reduction, solving this problem depends on the factors which contribute to the achievements of this comfort. Modern buildings -- implicitly teaching unit -- may be equipped with installations which have low energy consumption, respective a heating, cooling and ventilating integrated system with heat pumps system which can assure all the required comfort conditions. This paper underlines the necessity to use the heat pump in heating system for a teaching unit, energetic and economic guides and the possibility to increase them when using cooling and heating mixed. The solution of heat pumps for heating of the teaching unit and the energetic and economic advantages of the system is made in study.

The school buildings must be adapted to the social-educational necessities of the students, appropriate for the age and biological necessities in terms of shape dimensions and number of classrooms. The development in maximal conditions of the school functions is achieved by the building rules that are secured by the pedagogical, hygienic and administrative postulates of modern schools. The quality of the indoor environment affects the teaching process, being in direct concordance with the student performances. The paper evidences the necessity to unify criteria and parameters regarding the ambient comfort in civil buildings, especially in teaching units.