Estados Unidos
Estados Unidos

myGeobrugg

Estabilização de taludes - West St Leonards 2020

Panoramic view of the full railway cutting with the platform in the foreground

Estabilização de taludes - West St Leonards 2020

Drilling continues on the railway cutting as a train passes. TECCO® GREEN can be seen installed in the distance

Estabilização de taludes - West St Leonards 2020

The finished slope, TECCO® GREEN installed with P33/40 spike plates, train passing below the stabilised slope

Estabilização de taludes - West St Leonards 2020

View from the top of the railway cutting showing the TECCO® GREEN and P33 spike plates prior to applying torque

Estabilização de taludes - West St Leonards 2020

Railway cutting with TECCO® GREEN stabilisation mesh completed

Estabilização de taludes - West St Leonards 2020

Completed project of TECCO® GREEN stabilization

Estabilização de taludes - West St Leonards 2020

.

 

Ano de instalação

2020

Situação inicial

A landslip in 2016 left a large back scar on the railway cutting adjacent to property boundaries. The over steepened slope needed to be stabilised to protect the rail line and also protect the gardens and boundaries of adjacent properties. Continued weathering of this slope has created a steeper and unsafe slope angle.

Prior to the failure, the slopes were heavily vegetated with mature tree cover. These large trees, although helping to stabilise the local soil, create big issues on a steep slope in adverse weather conditions and high winds. Tilt meters have been installed for the past four years to monitor the slope condition. 

Geologia

The boreholes drilled at ground investigate pre-tender stage showed the ground being Wadhurst Clay, primarily clays and extremely weak mudstone with some weak sandstone also shown, leading the design to be produced for self-drilling soil nails. However, from trials (both scheduled and additional), we found much harder and prominent ground encountered at all depths, which was likely missed at ground investigation stage due to heavy faulting through Bo Peep Tunnel at the eastern extremity of the site.

The major fault through the tunnel is documented in a paper written about the reconstruction of the tunnel following partial collapse due to groundwater ingress, associated with the faulting. Following extensive devegetation of the slope, extremely hard limestone can be seen outcropping at one location on the site, suspected to be the hard band encountered at varying depths across the slope.

Descrição

Engineers Tony Gee and Partners set about designing a scheme for the full slope length. Due to the limited access at the crest, raised trunking, cable routes, signals at the base of the slope, and requirements to keep the Tonbridge to Hastings rail line open. A soil nailing stabilisation was chosen. The use of on slope drill rigs (skid rigs) attached to crest mounted anchors allowed for the installation of soil nails in a grid pattern over the full slope height and length.

The Works undertaken by BAM Ritchies involved drilling of just over 1400 soil nails of varying lengths (from 1.5 m to 9.0 m), with primary lengths being 7.0 m and 9.0 m, specifically in the area of the previous landslip.

Soil nails consist of 25 mm dia. solid bar, upper 2 m of tendon galvanised. Soil nails were drilled using 3 Terrapin rigs, winched across the face using bar anchors on the crest of the slope. Air flush was supplied by compressors located on the crest, with drilling methodology changing from DTH to drag bit, highly dependent on ground conditions encountered. All works were undertaken using rope access techniques with no impact on the operational running of the railway.

Following drilling, mesh installation consisted of laying just over 6000 m² of TECCO® GREEN G65/3 over the entirety of the slope face, with extremely tight access points and areas with no crest line limiting the drop lengths possible to install in one go. Only access points at either end of the 220 m long cutting, with a middle access point allowed to be used as minimally as possible due to it being a residents' driveway. Mesh was then finished with TECCO® P33/40 spike plates on each soil nail, a domed nut, and perimeter cable.

Promotor

Contratante

Objecto protegido

Caminho de ferro, Edifício, Infra-estrutura

Proteção contra a corrosão

GEOBRUGG SUPERCOATING

O seu contacto local

Kevin H. Coyle
 

Kevin H. Coyle

Regional Manager Northeast

Riscos naturais
Engenharia Hidráulica
Geobrugg North America, LLC,3 Beaudet Terr,Columbia CT 06237 / Estados Unidos Regional Manager Northeast

E-mail

Saleh Feidi
 

Saleh Feidi

Regional Manager California

Riscos naturais
Engenharia Hidráulica
Geobrugg North America, LLC,8921 Emperor Ave.,San Gabriel, California 91775 / Estados Unidos Regional Manager California

E-mail

John Kalejta
 

John Kalejta

Regional Manager Central US

Riscos naturais
Engenharia Hidráulica
Geobrugg North America, LLC,3215 67th Avenue Pl,Greeley CO 80634 / Estados Unidos Regional Manager Central US

E-mail

Bob Lyne
 

Bob Lyne

Regional Manager Southeast

Riscos naturais
Engenharia Hidráulica
Geobrugg North America, LLC,8004 Windspray Drive,Summerfield NC 27358 / Estados Unidos Regional Manager Southeast

E-mail

Pierce Runnels, Civil Engineer
   

Pierce Runnels

General Manager Geobrugg North America

Riscos naturais
Geobrugg North America, LLC,22 Centro Algodones , Civil Engineer General Manager Geobrugg North America

E-mail

Tim Shevlin
 

Tim Shevlin

Sales Director

Riscos naturais
Geobrugg North America, LLC,Salem OR 97302 / Estados Unidos Sales Director

E-mail