New Testing Plans: Drilled Steel CT-pile Wall at Isosuo Landfill in City of Naantali

Today we are provaiding you article written by Liisa Larkela, who teaches geotechnics in Turku University of Applied Sciences. Enjoy!

 

New Testing Plans: Drilled Steel CT-pile Wall at Isosuo Landfill in City of Naantali

General

Turku University of Applied Sciences has done research of micropiles. During last few years it has created a new innovative open section C-pile and tested it in different locations and soil profiles.

If the C-pile has a special T-part it may be used as a pile wall. This so called CT-pile wall profile in is planned to be tested in Naantali Isosuo Landfill on December 2014.

Where CT-pile wall could be suitable?

Installation of usual sheet pile wall can be challenging for example in rocky soils. In many cases, drilled wall would be handy but conventional drilled pile walls on market are heavy and expensive for small construction sites.

In some areas, for example landfills, water proof structures is a requirement to prevent pollution leakage. A CT-pile wall can be grouted with cement to almost waterproof structure (depending on the cement mixture). If prevention structures are not built beforehand, CT-pile wall could be one option.

Testing plan

In Naantali, CT-pile wall of 20 pcs and to length of 6 to 8 meters will be drilled to ground. The soil profile consists of clay, silt, gravel and moraine and possibly bedrock. The CT-pile wall has never been drilled to inhomogeneous soil before.

Five piles of the wall will be injected with cement. Diameter of one CT-pile is 139.7 mm and the wall thickness is 6mm. Drilling bit diameter is 150mm. During the test deflections and observations will be conducted. 

Measurements of movements

Soil surface displacements will be measured after installation of the wall. It is predicted, that some movement will take place but it is also assumed that the benefits of the small diameter drilling bit (and pile) will be found and the settlements/movements will be quite small.

Author: Liisa Larkela, Turku University of Applied Sciences

General Organizer: Turku University of Applied Sciences

Drilling Work: Suomen Teräspaalutus Oy

Provider of Test Area: City of Naantali

Pile Manufacturer: Trameta Oy, Turku

Drill Head Manufactures: Robit Rocktools Ltd