Abstract

"jats:p" The norms and standards for design of timber bridges, as well as other structures built from this material, were obsolete, design standards that were used dated from 1978 to 1980. The introduction of European Standards has created a new legislative framework in the field of designing and building timber bridges. Currently the design of such constructions use Norm NP 005-2003 and SR EN 1995-1-1: 2004 Eurocode 5: Design of timber structures. Part 1-1: General. Common rules and rules for buildings, SR EN 1995-2: 2005 Eurocode 5: Design of timber structures. Part 2: Bridges, along with their national annexes. The aim of this paper is to analyze the design of the beams for timber bridges in parallel, using on one hand Norm NP 005 - 2003, and on the other hand provisions of European standards. The design requirements for both norms as well as the results of a case study for a structural element of a timber bridge will be presented. Document type: Article

Abstract

The present paper describes the first steps of the research project by the title “Repair connection with wooden wedged dowels. New and alternative repair method that meets the demands of Monument Protection of built substance’s gentle care and material fairness”. The project aims to develop guidelines for static-constructive use of wood-wood repair connections with wooden wedged dowels. In the research project, the first steps for the description of the mechanical model for the wooden wedged dowels have been approached. Literature about wooden pegs and dowels and built examples of wooden wedged dowels in existing buildings have been analyzed; more, preliminary laboratory tests and FEM simulations have been implemented.In this paper, the results of the preliminary laboratory tests and the parallel development of a FEM model with the aim of describing the deformation behavior of the wooden wedged dowels for the most used wooden species will be presented. The main aims are: a) Analysis of the distribution of the strains / deformations in the dowel and in the connected building components when inserting the wedge. b) Analysis of the risk of opening of cracks in the materials. c) Analysis of distribution of stresses in the dowel and in the connected building elements utilizing FEM modeling calibrated on the experimental results. Thanks to the evaluation of deformation behavior in the proposed geometrical configuration and material combinations of wedge, dowel and connected building elements, it has been possible to understand the general framework of deformation behavior and failure modes for different combinations of timber density of the connection components.

Abstract

Resistance drilling devices are commonly used for the onsite inspection of wood and timber structural components in existing buildings. Although they provide a measure related to the density variation along a section of an element, results are used mainly qualitatively, due to several parameters that affect the computed values. In this paper, several new and old timber elements, taken from the dismantling of original roofs from a large existing historical building in northern Italy, are tested through a series of ND (non-destructive), SD (semi-destructive) and destructive testing procedures. Various wood species (spruce, fir, larch, oak, elm, pine) are taken into consideration. Among the applied testing methods (visual inspection, resistance drill, ultrasonic, needle penetration, radar, lab tests bending/compression), not all reported here, a focus on the resistance drill tests results is addressed, to evaluate the influence of consumption of the needle tip on the amplitude output. This was done by correlating the drillings to a reference sample on each test position to obtain data with an enhanced quantitative content. From the visual old timber elements grading, SD tests execution and successive element strength characterization through laboratory tests, it finally emerged the need for proper calibration of assessment methodologies through the application of a combined approach, in order to achieve more reliable results.

Abstract

Alan Conisbee & Associates and Richard Ireland were engaged by the Royal Household Property Section to inspect and assess the historic plaster ceilings and their supporting structure within Buckingham Palace and Windsor Castle. Following the partial collapse of the Apollo Theatre ceiling in London in 2013 great importance has been placed on the inspection and certification of all historic plaster ceilings throughout the United Kingdom. This paper presents the key challenges of the project included the facilitation of access to constrained spaces, asbestos removal and cleaning of delicate fabric, surveying, digital monitoring, structural and plaster defects. Furthermore we discuss the key project outcomes including lessons learnt and best practice methodologies and practicalities behind inspections of this kind. The paper concludes with an outline of significant discoveries and ongoing laboratory testing of undernailed historic timber connections.