{"id":14609,"date":"2020-07-16T12:32:36","date_gmt":"2020-07-16T10:32:36","guid":{"rendered":"https:\/\/www.icop.it\/the-sectors\/microtunnelling-direct-pipe\/pulling-back\/"},"modified":"2025-02-05T12:43:35","modified_gmt":"2025-02-05T11:43:35","slug":"pulling-back","status":"publish","type":"page","link":"https:\/\/www.icop.it\/en\/the-sectors\/microtunnelling-direct-pipe\/pulling-back\/","title":{"rendered":"Pulling back"},"content":{"rendered":"<div id='layer_slider_1'  class='avia-layerslider main_color avia-shadow  avia-builder-el-0  el_before_av_one_half  avia-builder-el-first  container_wrap sidebar_left' style='  height: 351px; max-width: 1280px; margin: 0 auto;' ><\/div><div id='after_layer_slider_1'  class='main_color av_default_container_wrap container_wrap sidebar_left' style=' '  ><div class='container' ><div class='template-page content  av-content-small units'><div class='post-entry post-entry-type-page post-entry-14609'><div class='entry-content-wrapper clearfix'>\n<div class=\"flex_column av_one_half  flex_column_div av-zero-column-padding first  avia-builder-el-1  el_after_av_layerslider  el_before_av_one_half  avia-builder-el-first  \" style='border-radius:0px; '><section class=\"av_textblock_section \"  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\" ><div class='avia_textblock  '   itemprop=\"text\" ><h4><strong>PULLING BACK<\/strong><\/h4>\n<p>The pulling back technique is a technical solution that consists in executing a blind hole microtunnel, that is without an arrival shaft. The drilling shield, pushed from the starting shift through the definitive tubes, advances along the project trajectory until reaching the end, where it is recovered by applying a \u201cpulling back\u201d procedure. When the perforation is finished, the drilling shield is freed from the exca-vation head and the extension kit, and it is then slid back into the reinforce concrete piping, by means of a winch installed in the starting shaft, where it is recovered.<\/p>\n<p>This is possible thanks to a particular drilling cutter, equipped with a double shield: the first shield (in-ternal) has a diameter slightly smaller than the internal diameter of the reinforced concrete pipes, while the second shield (external) has a diameter approximately equal to their external diameter. In this way, the first shield can slide inside the tunnel and then it can be extracted from the starting shaft; the second shield and the cutting head, instead, remain in place.<\/p>\n<\/div><\/section><\/div><div class=\"flex_column av_one_half  flex_column_div av-zero-column-padding   avia-builder-el-3  el_after_av_one_half  el_before_av_one_full  \" style='border-radius:0px; '><div  class='avia-image-container  av-styling-    avia-builder-el-4  avia-builder-el-no-sibling  avia-align-center '  itemprop=\"image\" itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/ImageObject\"  ><div class='avia-image-container-inner'><div class='avia-image-overlay-wrap'><img class='avia_image' src='https:\/\/www.icop.it\/wp-content\/uploads\/2020\/04\/14_Pulling-back-3.jpg' alt='' title='14_Pulling back (3)' height=\"566\" width=\"566\"  itemprop=\"thumbnailUrl\"  \/><\/div><\/div><\/div><\/div><\/p>\n<div class=\"flex_column av_one_full  flex_column_div av-zero-column-padding first  avia-builder-el-5  el_after_av_one_half  avia-builder-el-last  column-top-margin\" style='border-radius:0px; '><p><div  style='padding-bottom:10px; color:#172f62;' class='av-special-heading av-special-heading-h2 custom-color-heading   avia-builder-el-6  el_before_av_masonry_entries  avia-builder-el-no-sibling  '><h2 class='av-special-heading-tag '  itemprop=\"headline\"  >Working sheets<\/h2><div class='special-heading-border'><div class='special-heading-inner-border' style='border-color:#172f62'><\/div><\/div><\/div><br \/>\n<div style='display:none'>14609<\/div><div id='unidea-filter-paesi'><span class='unidea-filter-paesi-all unidea-filter-paesi-active'>All<\/span> \/ <span class='unidea-filter-paesi-item ' data-filterpaese='Italy'>Italy<\/span><\/div><div id='av-masonry-1' class='av-masonry  noHover av-fixed-size av-large-gap av-hover-overlay-active av-masonry-animation-active av-masonry-col-3 av-caption-always av-caption-style-    '  ><div class='av-masonry-container isotope av-js-disabled ' ><div class='av-masonry-entry isotope-item av-masonry-item-no-image all_sort microtunnelling-direct-pipe_sort  pulling-back-en_sort '><\/div><a href=\"https:\/\/www.icop.it\/en\/works\/1348-roma-s-giovanni-t3\/\" data-settore='Microtunnelling and direct pipe|Pulling Back' data-paese='Italy' id='av-masonry-1-item-16572' data-av-masonry-item='16572' class='av-masonry-entry isotope-item post-16572 prodotti type-prodotti status-publish has-post-thumbnail hentry settori-microtunnelling-direct-pipe settori-pulling-back-en paesi-italy all_sort microtunnelling-direct-pipe_sort  pulling-back-en_sort  av-masonry-item-with-image ' title=\"38_RomaSGiovanni_COPERTINA\"  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\"  ><div class='av-inner-masonry-sizer'><\/div><figure class='av-inner-masonry main_color'><div class=\"av-masonry-outerimage-container\"><div class=\"av-masonry-image-container\" style=\"background-image: url(https:\/\/www.icop.it\/wp-content\/uploads\/2020\/07\/38_RomaSGiovanni_COPERTINA-705x358.jpg);\" title=\"38_RomaSGiovanni_COPERTINA\" ><\/div><\/div><figcaption class='av-inner-masonry-content site-background'><div class='av-inner-masonry-content-pos'><div class='av-inner-masonry-content-pos-content'><div class='avia-arrow'><\/div><h3 class='av-masonry-entry-title entry-title '  itemprop=\"headline\" >1348 &#8211; Rome &#8211; S. Giovanni T3 (Italy)<\/h3><\/div><\/div><\/figcaption><\/figure><\/a><!--end av-masonry entry--><a href=\"https:\/\/www.icop.it\/en\/works\/1364-bologna-stazione-centrale\/\" data-settore='Microtunnelling and direct pipe|Pulling Back' data-paese='Italy' id='av-masonry-1-item-16552' data-av-masonry-item='16552' class='av-masonry-entry isotope-item post-16552 prodotti type-prodotti status-publish has-post-thumbnail hentry settori-microtunnelling-direct-pipe settori-pulling-back-en paesi-italy all_sort microtunnelling-direct-pipe_sort  pulling-back-en_sort  av-masonry-item-with-image ' title=\"33_Bologna_COPERTINA\"  itemscope=\"itemscope\" itemtype=\"https:\/\/schema.org\/CreativeWork\"  ><div class='av-inner-masonry-sizer'><\/div><figure class='av-inner-masonry main_color'><div class=\"av-masonry-outerimage-container\"><div class=\"av-masonry-image-container\" style=\"background-image: url(https:\/\/www.icop.it\/wp-content\/uploads\/2020\/07\/33_Bologna_COPERTINA-529x705.jpg);\" title=\"33_Bologna_COPERTINA\" ><\/div><\/div><figcaption class='av-inner-masonry-content site-background'><div class='av-inner-masonry-content-pos'><div class='av-inner-masonry-content-pos-content'><div class='avia-arrow'><\/div><h3 class='av-masonry-entry-title entry-title '  itemprop=\"headline\" >1364 &#8211; Bologna &#8211; Central Station (Italy)<\/h3><\/div><\/div><\/figcaption><\/figure><\/a><!--end av-masonry entry--><\/div><\/div><\/p><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"parent":14497,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/pages\/14609"}],"collection":[{"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/comments?post=14609"}],"version-history":[{"count":5,"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/pages\/14609\/revisions"}],"predecessor-version":[{"id":25443,"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/pages\/14609\/revisions\/25443"}],"up":[{"embeddable":true,"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/pages\/14497"}],"wp:attachment":[{"href":"https:\/\/www.icop.it\/en\/wp-json\/wp\/v2\/media?parent=14609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}