1.0SADEhttps://www.sade-cgth.fr/en/laurieannhttps://www.sade-cgth.fr/en/blog/author/laurieann/rich600338<blockquote class="wp-embedded-content" data-secret="klj5tftjdI"><a href="https://www.sade-cgth.fr/en/blog/geography/africa-en/a-first-for-lyon/">A first for Lyon…</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://www.sade-cgth.fr/en/blog/geography/africa-en/a-first-for-lyon/embed/#?secret=klj5tftjdI" width="600" height="338" title="“A first for Lyon…” — SADE" data-secret="klj5tftjdI" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script type="text/javascript"> /* <![CDATA[ */ /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); /* ]]> */ </script> https://www.sade-cgth.fr/wp-content/uploads/2021/01/GG-6.jpg18201216[vc_row][vc_column width=”2/3″][vc_column_text css=”.vc_custom_1610728903020{margin-right: 20px !important;}”]In Lyon, Gantelet-Galaberthier has dug a tunnel 5 metres under the water table and 8 metres under natural ground level, using a standard sheltered technique with jet grouting in the soil mass. The Lyon subsidiary set itself the impressive challenge of creating the final section of these sewer mains along 180m! This is the first time a gallery has been dug using traditional methods in the alluvium of the Saône river. To achieve this, a technique had to be devised in order to create a waterproof underground mass, from surface level, around the future location of... +