{"id":613,"date":"2013-07-08T16:06:33","date_gmt":"2013-07-08T15:06:33","guid":{"rendered":"http:\/\/blogs.bath.ac.uk\/structures\/?p=613"},"modified":"2013-07-08T16:06:33","modified_gmt":"2013-07-08T15:06:33","slug":"question-19","status":"publish","type":"post","link":"https:\/\/blogs.bath.ac.uk\/structures\/2013\/07\/08\/question-19\/","title":{"rendered":"Question 19"},"content":{"rendered":"<p>Judging from last weeks performance quite a few of you have forgotten \u00a0how to draw BMD. So the next few questions will focus on this \u00a0issue.<\/p>\n<p>The question focusses on \u00a0a 3 span \u00a0bridge with a \u00a0drop-in span in the middle similar to the Ness Bridge in Inverness Scotland, check out the\u00a0<a href=\"http:\/\/happypontist.blogspot.gr\/\">Happy pontist blog<\/a>: a \u00a0great \u00a0resource from \u00a0civil engineering \u00a0students.<\/p>\n<p style=\"text-align: center\"><strong>Please identify the INCORRECT BMDs<\/strong><\/p>\n<p style=\"text-align: center\"><a href=\"http:\/\/bathblogs.wpengine.com\/structures\/wp-content\/uploads\/sites\/51\/2013\/07\/question19.jpg.png\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-633 aligncenter\" src=\"http:\/\/bathblogs.wpengine.com\/structures\/wp-content\/uploads\/sites\/51\/2013\/07\/question19.jpg.png\" alt=\"question19.jpg\" width=\"469\" height=\"362\" srcset=\"https:\/\/blogs.bath.ac.uk\/structures\/wp-content\/uploads\/sites\/51\/2013\/07\/question19.jpg.png 976w, https:\/\/blogs.bath.ac.uk\/structures\/wp-content\/uploads\/sites\/51\/2013\/07\/question19.jpg-300x231.png 300w\" sizes=\"auto, (max-width: 469px) 100vw, 469px\" \/><\/a><\/p>\n<p><strong>HINT. <em>The\u00a0 trick\u00a0 with\u00a0 such\u00a0 'drop-in' structures  is that the double pin in the middle isolates the effects of load (  moment) from\u00a0 either side. That is to say that a load on the\u00a0 first span  \u00a0cannot produce any moment on the middle or\u00a0 third span.<\/em>UPDATE 15\/7\/13. <\/strong>Judging \u00a0from the number of incorrect answers this \u00a0question \u00a0has \u00a0received I will be leaving it \u00a0up \u00a0for \u00a0a couple of \u00a0days \u00a0more.<\/p>\n<p>If\u00a0you\u00a0 draw the deflected shape for the case where there load is at any point between the first\u00a0 support and the adjacent pin, you\u00a0 should see that\u00a0 the  middle span(between pins ) is always straight just\u00a0 rotated slightly)<\/p>\n<p>Try the question again and attempt to draw the deflected shapes.<\/p>\n<p><span style=\"color: #ff0000\"><strong>SOLUTION: 17\/6\/13. <\/strong>A,C,D are the INCORRECT BMDs (this is what \u00a0you were asked to submit) \u00a0the \u00a0rest of them (B,E and F) are the correct BMD for the structure.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Judging from last weeks performance quite a few of you have forgotten \u00a0how to draw BMD. So the next few questions will focus on this \u00a0issue. The question focusses on \u00a0a 3 span \u00a0bridge with a \u00a0drop-in span in the...<\/p>\n","protected":false},"author":203,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4],"tags":[],"class_list":["post-613","post","type-post","status-publish","format-standard","hentry","category-beams"],"acf":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/posts\/613","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/users\/203"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/comments?post=613"}],"version-history":[{"count":0,"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/posts\/613\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/media?parent=613"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/categories?post=613"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.bath.ac.uk\/structures\/wp-json\/wp\/v2\/tags?post=613"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}