{"version":"1.0","provider_name":"Robbins","provider_url":"https:\/\/www.robbinstbm.com\/zh-hans\/","title":"Tunneling in Mixed Face Conditions: An Enduring Challenge for EPB TBM Excavation - Robbins","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"TiB49pRQlz\"><a href=\"https:\/\/www.robbinstbm.com\/zh-hans\/tunneling-in-mixed-face-conditions\/\">Tunneling in Mixed Face Conditions: An Enduring Challenge for EPB TBM Excavation<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.robbinstbm.com\/zh-hans\/tunneling-in-mixed-face-conditions\/embed\/#?secret=TiB49pRQlz\" width=\"600\" height=\"338\" title=\"&#8220;Tunneling in Mixed Face Conditions: An Enduring Challenge for EPB TBM Excavation&#8221; &#8212; Robbins\" data-secret=\"TiB49pRQlz\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/* <![CDATA[ *\/\n\/*! This file is auto-generated *\/\n!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);\n\/\/# sourceURL=https:\/\/www.robbinstbm.com\/wp-includes\/js\/wp-embed.min.js\n\/* ]]> *\/\n<\/script>\n","thumbnail_url":"https:\/\/www.robbinstbm.com\/wp-content\/uploads\/2019\/07\/Image-4-RGB.jpg","thumbnail_width":3510,"thumbnail_height":2340,"description":"EPB TBM tunneling in mixed face conditions\u2014partially in both rock and soil\u2014is inherently problematic for even the most experienced crews. Over-excavation, excessive damage to cutter tools and regular cutterhead interventions are major challenges when negotiating mixed face geology. This paper draws from real field experiences, including successful bores in abrasive rock and soil at India\u2019s Chennai and Bangalore metro projects, to determine the optimal operational parameters for TBMs in such conditions."}