Explore the vast range of titles available.

In the case of masonry structures subjected to seismic loads, shear failure mechanism of walls, characterised by the formation of diagonal cracks, by far predominates the sliding shear failure mechanism. However, as assumed by Eurocode 6, the latter represents the critical mechanism for the assessment of the shear resistance of structural walls. The results of a series of laboratory tests are analysed to show that in the case of the diagonal tension shear failure the results of the Eurocode 6 based calculations are not in agreement with the actual resistance of masonry walls. The results of calculations, where the diagonal tension shear mechanism and tensile strength of masonry are considered as the critical parameters, are more realistic. Since the results of seismic resistance verification, based on the Eurocode 6 assumed sliding shear mechanism, are not in favour of structural safety, it is proposed that in addition to sliding shear, the diagonal tension shear mechanism be also considered. Besides, in order to avoid misleading distribution of seismic actions on the resisting shear walls, the deformability characteristics of masonry at shear should be determined on the basis of experiments and not by taking into account the Eurocode 6 recommended G / E ratio.

Seismic design using maps based on “risk-targeting” would lead to an annual probability of attaining or exceeding a certain damage state that is uniform over an entire territory. These maps are based on convolving seismic hazard curves from a standard probabilistic analysis with the derivative of fragility curves expressing the chance for a code-designed structure to attain or exceed a certain damage state given a level of input motion, e.g. peak ground acceleration (PGA). There are few published fragility curves for structures respecting the Eurocodes (ECs, principally EC8 for seismic design) that can be used for the development of risk-targeted design maps for Europe. In this article a set of fragility curves for a regular three-storey reinforced-concrete building designed using EC2 and EC8 for medium ductility and increasing levels of design acceleration ( a g ) is developed. These curves show that structures designed using EC8 against PGAs up to about 1 m/s 2 have similar fragilities to those that respect only EC2 (although this conclusion may not hold for irregular buildings, other geometries or materials). From these curves, the probability of yielding for a structure subjected to a PGA equal to a g varies between 0.14 ( a g = 0.7 m/s 2 ) and 0.85 ( a g = 3 m/s 2 ) whereas the probability of collapse for a structure subjected to a PGA equal to a g varies between 1.7 × 10 - 7 ( a g = 0.7 m/s 2 ) and 1.0 × 10 - 5 ( a g = 3 m/s 2 ) .

The present work aims to analyze problems and obstacles to innovation faced by architectural and engineering services companies in Brazil, focusing on standardization and regulation issues. We have drawn the data from the National Innovation Survey 2014 (Pintec 2014) to answer how the companies in this sector perceive the importance of problems and obstacles throughout their cycles of innovation concerning difficulties of meeting government regulations, legal or voluntary standards requirements, and accessing specialized technical/technological services. The respondent companies were asked to inform their perceptions of the importance of the barriers that they face to innovate in a three-point response scale (high, medium, and low importance or not relevant).

Quality inspection plays an important role in the production process of concrete, as it inherently stimulates producers for obtaining a higher performance with respect to the investigated properties. In case of the conformity assessment of concrete compressive strength, the concrete strength distribution is filtered due to the rejection or acceptance of certain batches and this filter effect can be quantified using Bayesian updating techniques. As a consequence of the filter effect, conformity control has a positive influence on the structural reliability of concrete structures. This filter effect can be quantified by using an approximation method as developed herein or also by using classical FORM/SORM techniques. In order to illustrate the influence of conformity control on structural reliability, concrete elements (columns and beams) which are designed according to the Eurocodes, are analysed considering basic limit state equations, i.e. for compression and bending. Moreover, the influence of the reinforcement ratio and the load ratio on the filter effect is investigated. Numerical analyses reveal that the filter effect may positively influence especially reliability of lightly reinforced concrete members exposed to compression. It appears that it has a minor effect where reinforcement properties govern failure.

This paper describes the development of the 2004 Canadian Standards Association (CSA) A23.3 shear design provisions for reinforced and prestressed concrete structures. These methods are similar to the 1994 standard in providing a simplified and general shear design method. They differ from previous standards by providing a direct link between these two methods and simple equations for the calculation of β and θ used in the general method rather than providing these values in a table. The paper explains the basic assumptions behind the new shear provisions, provides a derivation of the new equations, and compares designs made with the new equations to designs obtained from previous standards. In general, the new shear provisions require slightly less shear reinforcement than that required by the previous standard. The new general method is significantly easier to use, particularly with spreadsheets.Key words: shear, building codes, reinforced concrete, size effect, structural design.

The objective of this paper is to identify the type of barriers related to the implementation of a new Water Law in Nicaragua. By exploring the perceptions of 40 actors involved in the drafting process of the Law, this paper finds that major barriers are related to the power configuration of the water administration set-up, which creates conflicts of competences within government and at local and national levels. Our research suggests that decision-making is highly centralized, whereas local governments remain unpowered despite their relevant role in water management. One of the particular novel aspects of this paper is the linking of interview data to grammar-coded institutional statements along the social–ecological systems' variables. The institutional grammar tool is used to identify the institutional statements of the Nicaraguan Water Law and to connect the interview results to the institutional configuration of the Water Law. This allows us to understand to what extent the Water Law modifies both the formal and informal institutions that are in place.

The recommendations presented in this publication are inspired by the State of the Art Report edited by the RILEM Technical Committee TC 193 RLS Bonded cement - based material overlays for the repair, the lining or the strengthening of slabs and pavements. The objective is to lay out all the practical aspects to be considered in the design of concrete overlays: bonded concrete overlay process, assessment of the existing structure, surface preparation, overlay materials, design methods, construction procedure and quality control/assurance system, and maintenance.