{"id":2510,"date":"2024-10-11T07:42:19","date_gmt":"2024-10-11T07:42:19","guid":{"rendered":"https:\/\/seabrokers.no\/fundamentering\/?post_type=referanser&p=2510"},"modified":"2024-10-11T07:44:13","modified_gmt":"2024-10-11T07:44:13","slug":"dolo-reff-9-karlatornet-i-goteborg-jetgrunn-2","status":"publish","type":"referanser","link":"https:\/\/seabrokers.no\/fundamentering\/en\/referanser\/dolo-reff-9-karlatornet-i-goteborg-jetgrunn-2\/","title":{"rendered":"Dolo Reff 10 Unik og Innovativ l\u00f8smassetunnel, Porsgrunn JETGRUNN"},"content":{"rendered":"

Unique and innovative loose mass tunnel opened in Porsgrunn<\/strong><\/p>\n

The collaborative project between AF Gruppen, Norconsult and Jetgrunn on the construction of the Hovenga bulk tunnel is now complete,<\/p>\n

and the facility was officially opened on 17 December 2018. The tunnel, which is part of “Bypakke Grenland”, represents a<\/p>\n

ground-breaking solution in building in bulk. It is the first bulk tunnel in the world to be constructed with one<\/p>\n

permanent, unreinforced base plate made of geoconcrete piles, while dimensioned to resist buoyancy.<\/p>\n

Solution<\/strong><\/p>\n

The loose mass tunnel has been built to meet strict requirements for pore pressure, deformations and tightness. When using permanent<\/p>\n

sheet pile walls combined with an unreinforced base plate, a rigid, watertight structure was established prior to excavation of<\/p>\n

the loose masses. Between the sheet pile walls, a pressure arch of jet piles is formed to resist the forces from buoyancy, without<\/p>\n

cracks or unacceptable shear stresses in the construction. This method has ensured stability and minimized deformations.<\/p>\n

\u00a0<\/strong><\/p>\n

Method<\/strong><\/p>\n

The project encountered challenging ground conditions, with layers of quicksand and a high groundwater level. To ensure safety against<\/p>\n

buoyancy, the jet piles were dimensioned according to Eurocode 7. The permanent bottom plate and the tunnel construction lie below<\/p>\n

the groundwater level, and buoyancy safety was ensured both during the construction phase and permanently.<\/p>\n

The construction method produced a low CO2 footprint, among other things by using low-carbon cement and by avoiding separate, temporary<\/p>\n

constructions. The permanent construction served as boats<\/p>\n

bracing and sealing during the entire construction period.<\/p>\n

This innovative approach represents a significant advance<\/p>\n

in the development of loose mass tunnels.<\/p>\n

Compressive strength (J2 piles and EC1 piles)<\/p>\n

During the establishment of the J2 piles, samples were taken from them<\/p>\n

the return material and molded spout cubes for pressure testing (ex.)<\/p>\n

From experience, the compressive strength is somewhat lower in the return material than in<\/p>\n

the pile itself.<\/p>\n

The dice from the production of EC1 piles are based on samples from<\/p>\n

the ready-mixed concrete delivered to the construction site. 288 dice were printed<\/p>\n

from J2 piles and 120 dice from EC1 piles.<\/p>\n

Jetgrunn’s work in connection with the loose mass tunnel at Hovenga was completed in the summer of 2017. AF started excavation of<\/p>\n

the tunnel in late summer 2017, and the breakthrough came on 23 November of the same year. After that time, AF continued to work on<\/p>\n

completion of the road surface, wall cladding and technical installations, and completed the works as planned in autumn 2018.<\/p>\n

The road was opened to traffic on 7\/12-2018, with an official opening on 17\/12-2018.<\/p>\n

Both the client (the Swedish Road Administration) and the main contractor (AF GRUPPEN) are very satisfied with the result. As expected<\/p>\n

the construction is waterproof, and meets all the requirements that were set for both tightness and strength;<\/p>\n","protected":false},"featured_media":2514,"parent":0,"menu_order":1,"template":"","meta":{"_links_to":"","_links_to_target":""},"class_list":["post-2510","referanser","type-referanser","status-publish","hentry","reference-type-dolomiti-refferanser-eng"],"acf":{"subtitle":"Referanse","title":"Unik og Innovativ l\u00f8smassetunnel, Porsgrunn JETGRUNN","text":"","buttons":null,"image":"","video":"","focus_point":"end","style":"dark","type":"full","overlay_opacity":60,"enable_animation":false,"lottie":"","animation_opacity":60},"_links":{"self":[{"href":"https:\/\/seabrokers.no\/fundamentering\/en\/wp-json\/wp\/v2\/referanser\/2510","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/seabrokers.no\/fundamentering\/en\/wp-json\/wp\/v2\/referanser"}],"about":[{"href":"https:\/\/seabrokers.no\/fundamentering\/en\/wp-json\/wp\/v2\/types\/referanser"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/seabrokers.no\/fundamentering\/en\/wp-json\/wp\/v2\/media\/2514"}],"wp:attachment":[{"href":"https:\/\/seabrokers.no\/fundamentering\/en\/wp-json\/wp\/v2\/media?parent=2510"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}