{"id":33858,"date":"2026-04-27T13:06:01","date_gmt":"2026-04-27T13:06:01","guid":{"rendered":"https:\/\/protasoftware.com\/technical-manuals\/structural-modelling\/working-with-slab-openings-drops\/"},"modified":"2026-06-19T12:37:44","modified_gmt":"2026-06-19T12:37:44","slug":"working-with-slab-openings-drops","status":"publish","type":"wiki","link":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/","title":{"rendered":"Working With Slab Openings Drops"},"content":{"rendered":"

Slab Opening Properties<\/span><\/span>
<\/h1>\n\n\n\n
\n

<\/span><\/span><\/p>\n

<\/div>\n

 <\/p>\n<\/td>\n

\n
"Slab Opening Properties"<\/span><\/i><\/b> will be loaded when the <\/span>"<\/span><\/b><\/span>Slab Opening<\/span><\/b><\/span><\/i>"<\/span><\/b> option in the <\/span>"<\/span><\/b>Modelling<\/span><\/b><\/i>"<\/span><\/b> ribbon is selected. A new slab opening can be defined by arranging the fields in the form and then by clicking the insertion reference.<\/span><\/span><\/span><\/div>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
<\/div>\n

Slab Opening Dimensions (b1, b2)<\/span><\/h2>\n
Horizontal ("b1"<\/i><\/b>) and vertical ("b2"<\/i><\/b>) dimensions of the slab opening can be defined in these fields.<\/span><\/span><\/span>
<\/span><\/div>\n
<\/span>
<\/span><\/div>\n

Slab Opening Parameters<\/span><\/span><\/span>
<\/span><\/h1>\n

Slab Opening Reference Distances (e1, e2)<\/span><\/span>
<\/h2>\n
Slab openings are inserted based on an axis intersection as reference point. The horizontal distance ("e1"<\/i><\/b>) and vertical distance ("e2"<\/i><\/b>) to the lower left corner of the slab opening can be defined by picking a reference insertion point and pressing \u201cF2\u201d on keyboard. The \u201ce1\u201d<\/i><\/b> and \u201ce2\u201d<\/i><\/b> can be defined as coordinates (x, y) or polar (r<angle) with respect to the selected reference point.<\/span><\/span><\/span> <\/div>\n

<\/span><\/div>\n
The <\/b><\/i>\u201ce1\u201d<\/i><\/b> reference distance of opening is measured along the direction specified by the \u201cAngle\u201d<\/i><\/b> field. Similarly, \u201ce2\u201d<\/i><\/b> is measured perpendicular to the direction specified by the \u201cAngle\u201d<\/i><\/b> field.<\/span><\/span><\/span>
<\/span><\/div>\n

Alternatively, \u201ce1\u201d<\/i><\/b> and \u201ce2\u201d<\/i><\/b> can be defined by simply picking the reference (first point) and the insertion points (second point).<\/span><\/span><\/span>
<\/span><\/p>\n

Opening Angle<\/span><\/span>
<\/span><\/h2>\n
The "Opening Angle"<\/i><\/b> field allows you to define inclined slab openings. This is the angle of the bottom edge of the opening measured from horizontal axis.<\/span><\/span><\/span><\/div>\n

<\/span><\/span><\/p>\n

Inserting a New Slab Opening\/Drop<\/span><\/span><\/b><\/h1>\n<\/p>\n

The Slab should be created before the Slab Opening is inserted.<\/span><\/span><\/span>
<\/span><\/span><\/p>\n

To define a new Slab Opening\/Drop (Rectangular\/Circular)<\/span><\/span><\/u><\/span>
<\/span><\/span><\/p>\n

    \n
  1. Press the <\/span>\u201c<\/span><\/b><\/span>Slab Opening<\/span><\/b><\/span><\/i>\u201d<\/span><\/b> button located in <\/span>"<\/span><\/b>Modelling<\/span><\/b><\/i>"<\/span><\/b> tab.
    <\/span><\/span><\/li>\n
  2. Under type, select <\/span>"Rectangular" <\/span><\/i><\/b>or <\/span>"Circular"<\/span><\/i><\/b>.
    <\/span><\/span><\/li>\n
  3. Enter the opening dimensions (<\/span>"b1 "<\/span><\/i><\/b> and <\/span>"b2"<\/span><\/i><\/b>) and the angle of the opening lower edge with respect to the direction 1 (horizontal) axis. Check <\/span>"Drop Region Definition"<\/span><\/i><\/b> to create a slab drop and input Drop in mm. 
    <\/span><\/span><\/li>\n
  4.  Picking a reference point on plan or 3D views. Insertion point or the distances to the reference point (<\/span>"e1"<\/span><\/i><\/b> and <\/span>"e2"<\/span><\/i><\/b>) can be defined by picking the second point on the plan or 3D views. Alternatively, \u201cF2\u201d can also be used to define the <\/span>"e1"<\/span><\/i><\/b> and <\/span>\u201ce2\u201d<\/span><\/i><\/b> after picking the reference point.<\/span><\/span><\/li>\n<\/ol>\n
      \n
    1. \n

      <\/span><\/li>\n<\/ol>\n

      \"Info\"<\/p>\n
      If <\/span>\u201cF2\u201d<\/span><\/b> is used to define the<\/span> \u201ce1\u201d <\/span><\/b>and<\/span> \u201ce2\u201d<\/span><\/b>, the relative coordinates <\/span>\u201ce1\u201d<\/span><\/b> and <\/span>\u201ce2\u201d <\/span><\/b>shall be separated by a <\/span>\u201c , \u201d<\/span><\/b> , i.e. the format of the input shall be e1, e2.
      <\/span><\/span><\/div>\n
      For the polar coordinates, the radius shall be followed by a <\/span>\u201c < \u201d<\/span><\/b> before entering the angle, i.e. the format of the input shall be radius < angle.<\/span><\/span><\/div>\n

      <\/span><\/div>\n

      <\/div>\n
      \"Notes\" <\/p>\n
      For example, if you want to create a slab opening which 1500 mm distance away from the point A and with the angle of 45 degree. The value have to be input into the field is <\/span>1500 < 45<\/span><\/u><\/b>. (refer to <\/span><\/span> <\/span>the <\/span><\/span> <\/span>image below): <\/span><\/span><\/div>\n
      <\/span><\/div>\n

      <\/span><\/div>\n

      To define a new Slab Opening\/Drop (Irregular Shape)<\/span><\/span><\/u><\/span>
      <\/span><\/span><\/p>\n

        \n
      1. Press the <\/span>\u201c<\/span><\/b><\/span>Slab Opening<\/span><\/b><\/span><\/i>\u201d<\/span><\/b> button located in the "Modelling" tab.<\/span>
        <\/span><\/span><\/li>\n
      2. Under type, select <\/span>"<\/span><\/b><\/span>Polyline<\/span><\/b><\/span><\/i>"<\/span><\/b>.<\/span>
        <\/span><\/span><\/li>\n
      3. Click successively to define the<\/span><\/span> <\/span><\/span><\/span>corners<\/span><\/span><\/b><\/i> <\/span><\/span><\/span>of the drop. Last click to close the loop or right-click select <\/span>"<\/span><\/b><\/span>Close<\/span><\/b><\/span><\/i>"<\/span><\/b> to close the loop. <\/span>
        <\/span><\/span><\/li>\n
      4. To create drop, check the <\/span>"<\/span><\/b><\/span>Drop Region Definition<\/span><\/b><\/span><\/i>"<\/span><\/b>, input Drop in mm and click<\/span> "<\/span><\/b><\/span>Update<\/span><\/b><\/span><\/i>".<\/span><\/b>
        <\/span><\/span><\/li>\n<\/ol>\n

        Negative value is a drop & positive value is a raise. Example:<\/span><\/span><\/span>
        <\/span><\/span><\/p>\n

          \n
        • If the slab thickness is 150 mm & a  -50 mm drop is entered, then the slab thickness at the drop is 100 mm. 
          <\/span><\/span><\/li>\n
        • If a positive 50 mm value is entered, the slab will be thickened & raised with final depth of 200 mm. <\/span><\/span><\/li>\n<\/ul>\n

          Editing an Existing Slab Opening<\/span><\/span><\/b>
          <\/span><\/h1>\n
          In order to edit an existing Slab Opening:<\/span>
          <\/span><\/div>\n
            \n
          1. Select an existing slab opening.
            <\/span><\/span><\/li>\n
          2. Modify the fields such as opening dimensions in the <\/span>"<\/span><\/b><\/span>Slab Opening Properties<\/span><\/b><\/span><\/i>"<\/span><\/b> form.
            <\/span><\/span><\/li>\n
          3. Press the <\/span>"<\/span><\/b><\/span>Update<\/span><\/b><\/span><\/i>"<\/span><\/b> button in the form.
            <\/span><\/span><\/li>\n<\/ol>\n

            You can repeat this process to as many members as you wish. One opening at a time can be edited by this method. Opening created using polyline cannot be edited.<\/span><\/span><\/span><\/p>\n

            <\/div>\n","protected":false},"excerpt":{"rendered":"

            Slab Opening Properties   "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling" ribbon is selected. A new slab opening…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"template":"","meta":{"_whitepaper_youtube_videos":"","_whitepaper_youtube_url":"","_whitepaper_youtube_thumbnail":"","footnotes":""},"categories":[185],"whitepaper_topic":[],"whitepaper_product":[],"whitepaper_type":[],"class_list":["post-33858","wiki","type-wiki","status-publish","hentry","category-structural-modelling"],"yoast_head":"\nWorking With Slab Openings Drops - Prota Software<\/title>\n<meta name=\"description\" content=\"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Prota Software\" \/>\n<meta property=\"og:description\" content=\"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"\" \/>\n<meta property=\"og:url\" content=\"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/\" \/>\n<meta property=\"og:site_name\" content=\"Prota Software\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-19T12:37:44+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/desk.zoho.com\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:title\" content=\"Prota Software\" \/>\n<meta name=\"twitter:label1\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data1\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/\",\"url\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/\",\"name\":\"Working With Slab Openings Drops - Prota Software\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/desk.zoho.com\\\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839\",\"datePublished\":\"2026-04-27T13:06:01+00:00\",\"dateModified\":\"2026-06-19T12:37:44+00:00\",\"description\":\"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/#primaryimage\",\"url\":\"https:\\\/\\\/desk.zoho.com\\\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839\",\"contentUrl\":\"https:\\\/\\\/desk.zoho.com\\\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/working-with-slab-openings-drops\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/protasoftware.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Wiki\",\"item\":\"https:\\\/\\\/protasoftware.com\\\/wiki\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Working With Slab Openings Drops\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#website\",\"url\":\"https:\\\/\\\/protasoftware.com\\\/\",\"name\":\"Prota Software\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/protasoftware.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#organization\",\"name\":\"Prota Software\",\"url\":\"https:\\\/\\\/protasoftware.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/protasoftware.com\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/prota-logo.png\",\"contentUrl\":\"https:\\\/\\\/protasoftware.com\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/prota-logo.png\",\"width\":1200,\"height\":340,\"caption\":\"Prota Software\"},\"image\":{\"@id\":\"https:\\\/\\\/protasoftware.com\\\/#\\\/schema\\\/logo\\\/image\\\/\"}}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Working With Slab Openings Drops - Prota Software","description":"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/","og_locale":"en_US","og_type":"article","og_title":"Prota Software","og_description":"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"","og_url":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/","og_site_name":"Prota Software","article_modified_time":"2026-06-19T12:37:44+00:00","og_image":[{"url":"https:\/\/desk.zoho.com\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839","type":"","width":"","height":""}],"twitter_card":"summary_large_image","twitter_title":"Prota Software","twitter_misc":{"Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/","url":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/","name":"Working With Slab Openings Drops - Prota Software","isPartOf":{"@id":"https:\/\/protasoftware.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/#primaryimage"},"image":{"@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/#primaryimage"},"thumbnailUrl":"https:\/\/desk.zoho.com\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839","datePublished":"2026-04-27T13:06:01+00:00","dateModified":"2026-06-19T12:37:44+00:00","description":"Slab Opening Properties "Slab Opening Properties" will be loaded when the "Slab Opening" option in the "Modelling"","breadcrumb":{"@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/#primaryimage","url":"https:\/\/desk.zoho.com\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839","contentUrl":"https:\/\/desk.zoho.com\/DocsDisplay?zgId=672206093&mode=inline&blockId=9nkhd3ce0ae733d524d67aaa556242396d839"},{"@type":"BreadcrumbList","@id":"https:\/\/protasoftware.com\/wiki\/working-with-slab-openings-drops\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/protasoftware.com\/"},{"@type":"ListItem","position":2,"name":"Wiki","item":"https:\/\/protasoftware.com\/wiki\/"},{"@type":"ListItem","position":3,"name":"Working With Slab Openings Drops"}]},{"@type":"WebSite","@id":"https:\/\/protasoftware.com\/#website","url":"https:\/\/protasoftware.com\/","name":"Prota Software","description":"","publisher":{"@id":"https:\/\/protasoftware.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/protasoftware.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/protasoftware.com\/#organization","name":"Prota Software","url":"https:\/\/protasoftware.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/protasoftware.com\/#\/schema\/logo\/image\/","url":"https:\/\/protasoftware.com\/wp-content\/uploads\/2026\/07\/prota-logo.png","contentUrl":"https:\/\/protasoftware.com\/wp-content\/uploads\/2026\/07\/prota-logo.png","width":1200,"height":340,"caption":"Prota Software"},"image":{"@id":"https:\/\/protasoftware.com\/#\/schema\/logo\/image\/"}}]}},"_links":{"self":[{"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/wiki\/33858","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/types\/wiki"}],"author":[{"embeddable":true,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":1,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/wiki\/33858\/revisions"}],"predecessor-version":[{"id":36453,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/wiki\/33858\/revisions\/36453"}],"wp:attachment":[{"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/media?parent=33858"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/categories?post=33858"},{"taxonomy":"whitepaper_topic","embeddable":true,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/whitepaper_topic?post=33858"},{"taxonomy":"whitepaper_product","embeddable":true,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/whitepaper_product?post=33858"},{"taxonomy":"whitepaper_type","embeddable":true,"href":"https:\/\/protasoftware.com\/wp-json\/wp\/v2\/whitepaper_type?post=33858"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}