Tag
Author
Date published
Price

Contents page

The Structural Engineer

Mr. M. H. Rees (M) Dr. Harvey’s paper is a model of clarity of exposition (refreshingly jargonless) and the economical setting-up of a method of structural analysis developed by him and his colleagues primarily for the very practical investigation of existing, often ancient, masonry arches and buttresses. The thrustline is the primary tool used, and its most revealing derivative, the thrustzone. The notion of packers placed between masonry blocks is introduced to simplify and clarify the analysis. Two further techniques are used to facilitate the method: a separate partial factor is postulated for material strength to take into account the reduction in stability arising from bending in the structure (the P-Ä effect for both elastic and creep displacement); and the equivalent rectangular pressure stress block under the packer in place of the more difficult-to-handle triangular block - this despite the otherwise working-load nature of the analysis. Some interesting effects are highlighted, such as that of scaling up a structure in equilibrium to produce one that is not (by deduction, the converse rule will also apply to render a scaled-down structure more stable).

The Structural Engineer

Engineers are increasingly being called on to carry out appraisals of existing structures. The sources of information available to an engineer when carrying out an appraisal of an existing structure are: (1) existing documentation on the original design and construction and any subsequent modifications; (2) the maintenance history of the structure; (3) surveys of the structure providing information on: - as built-dimensions, reinforcement details, etc. - present loadings (from reassessment of current dead and imposed loads) - the physical condition and properties of the construction materials; - any visible defects; (4) relevant Codes of Practice and other guidance documents. R.M. Moss

The Structural Engineer

The effectiveness of the method of resin injection in restoring the structural integrity of crack-damaged rein forced concrete beams was investigated. Fourteen beams that had been tested previously under static loading in a study into the performance of patch repair materials' were resin injected. The beams were evaluated under three load systems, one static and two cyclic. Three of the beams were submerged in water at 38 °C for 4 months before being tested. Twenty-five cores were taken from the beams to study injected cracks under a microscope. A.I. Abu-Tair, S.R. Rigden and E. Burley

The Structural Engineer

Ask most people in the UK to name two properties of timber and they will reply ‘it rots’ and ‘it burns’. Ask the same question in almost any other developed country and they will quote properties such as versatility, workability, strength, beauty, etc. No doubt, it is partly because the industrial revolution was started this country (for which we should be justly proud) that our tradition for steel and concrete construction has become so entrenched. Yet European counterparts, in maintaining a neutral stance over material selection, have allowed themselves far greater scope economy and flexibility of form in their structures. The objective of this feature is to encourage teaching of timber engineering and a greater use of timber in primary structural applications. The feature forms part of a wider campaign by UKTEG to increase awareness, encourage debate and define specific courses of action concerning its subject-matter. UKTEG

The Structural Engineer

In May 1991 the Institution published Appraisal of sports grounds, resulting from the work of its task group set up after events at Hysel, Bradford, and Birmingham, and following publication of the Popplewell Inquiry report. Appraisal is complementary to the Guide to Safety at Sports Grounds, HMSO, November 1990, and incorporates, where appropriate, the recommendations of the Taylor Report which contained ‘recommendations about the needs of crowd control and safety at sports grounds.’ M.G.T. Dickson