Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Half measures

Letters

It was distressing to read of the Montreal road bridge collapse and the fatalities associated with the use of half-joints (NCE 5 October).

In the UK early half-jointed suspended spans on motorway bridges were often adopted to create an articulated statically determinate structure on pad footings accommodating differential settlement. These could be readily analysed with the aid of a slide-rule.

Codes of practice at the time did not contain specific rules for the design of such details. In-house rules were not developed at the firm where I worked from photoelastic models. Some years later the opportunity arose to load test to failure a half-scale model of one of our designs, which demonstrated the robust 'belt-and-braces' nature of the design that contained horizontal, vertical and inclined reinforcement.

However, despite this reassurance, neither the detrimental efforts of future chloride attack nor the inherent difficulties in inspecting halfjoints were fully recognised until much later.

Ken Weir (M ret), 40 Brookside Glen, Chesterfield, Derbyshire S40 3PF

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.