City View is an exciting new development in the New England Quarter of Brighton offering top quality office space next to the train station. The commercial benefit of the location in terms of transport links and proximity to London. Therefore the position of City View is in an area that is fast becoming a thriving business destination.
Urban Innovations (an architectural and urban design consultancy in Belfast) approached Enviromesh via an online enquiry. The outline brief for the City View development required a two-step solution to complement the architectural design of the building.
Following a series of preliminary meetings and initial design proposals. The design, material specifications (including the type of stone), as well as timescales and build-process were all agreed as part of the main contractor’s duties for overall site completion.
The architectural designers had specified a gabion cladding solution to the base and corner of the building. As a result, encasing a dual aspect full-height glazed area, with the sight lines extending outwards. This follows the line of a series of terraced, mass gravity gabion walls. Viewed from a distance the gabion cladding merges with the level of the terraced walls to form one endless ‘layer’. Subsequent landscaping and planting schemes would allow the structure to become a seamless factor of the surrounding urban landscape.
The installation of the gabion cladding was in progress whilst other site works were in progress. Coupled with the limited access and general site congestion, the main challenge was to ensure the continuous supply of materials. The limited space for working and the need to liaise with other companies on site who were sharing resources. As a result, the careful coordination of the works ensured the proposed build schedule remained.
During filling of the gabion units, scaffolding was the only means of access. This is as a result of there being no room for heavy machinery or lifting equipment. All stone was handballed in buckets to a landing stage, then wheelbarrowed to the gabion units for hand packing. This proved labour intensive.
The gabion cladding enclosing the dual aspect windows sat on a concrete sill above the windows. This gave an upper platform on to which the gabion units were then installed and filled. Once the top gabion units were filled and closed, they were capped with a second sill.
Lower down, the gabion units started on a base foundation and went up to the lower sill of the main windows. The design of the sills created a cap for the gabion units. This gave the display of an endless sight line to the verticle surfaces above and below the windows on both corners of the building.
GABION RETAINING WALL
The construction of a series of mass gravity gabion walls began with the rolled and compacted 6F5 foundations being prepared in varying depths from 150mm to 300mm to suit the size of each structure.
The gabion units were bespoke 675mm modules in order to reduce cell size which in turn would ensure good alignment of the wall’s face, free from deformation. Given the highly visible nature of this installation, these details were agreed during the early phases of the design and consultation to ensure the client’s aspirations were fully realised. This included hand-placing of the facing stones by the same team who installed the cladding, ensuring visual continuity throughout.
Each wall was inclined at 6 degrees from the vertical in line with the design and additionally required a non-woven needle-punched geotextile membrane to be installed to the rear of the units to prevent wash-through. The area behind the walls was then backfilled with imported 6N granular fill, rolled in 300mm layers, ready for accepting topsoil for later landscaping works by others.