Old Granada Studios in Manchester is an iconic landmark with a rich history. Once the headquarters of Granada Television, the studios have been home to some of the UK’s most beloved television programmes, including Coronation Street and University Challenge. It was also the site of The Beatles’ first television performance in 1962 and hosted the UK’s first general election debate in 2010. Today, the studios are being transformed into a dynamic cultural destination as part of the new St. John’s neighbourhood cluster, featuring workspaces, studios, hospitality venues, and entertainment facilities. Jamie Dempster of CCUK reports.
CCUK was approached to assess the strengthening requirements for certain elements of the structure as significant modifications were planned. The structural changes posed a challenge to the integrity of the original concrete elements, which had been designed according to the now-obsolete reinforced concrete design code CP 114(1). Given the need to accommodate new loads, the project was perfect for innovative strengthening solutions, leading to the adoption of carbon-fibre-reinforced polymer (CFRP).
Column strengthening
The initial scope included strengthening columns for axial loads and slabs for new riser openings. Originally, 117 columns required strengthening, but through detailed assessment and refinement with CCUK, this number was reduced to 38. The existing columns lacked sufficient capacity for the increased loads, necessitating additional reinforcement. The project’s structural engineer provided load assessments under both existing and proposed conditions and CCUK conducted feasibility studies to determine the effectiveness of a CFRP solution for strengthening the identified columns. After extensive technical discussions, a fully optimised design was developed, resulting in a requirement of an average of three layers of carbon fibre wrap per column.
The whole project was completed with an average of just four CCUK technicians on-site. Progress was swift, a small team were enabled, targeting an average of four columns strengthened per day. Simultaneously, the riser strengthening was carried out as the optimised design had reduced the number of risers needing CFRP to just three per floor.
Punching shear strengthening
The project expanded to include punching shear strengthening for a section designated for hotel use. The slabs in this area were subjected to increased loads, including additional storey loads, which led to higher punching shear forces at certain locations. The assessment by the project engineers indicated that some slabs failed in punching shear, though the increase in shear stress was marginal.
CCUK proposed a solution based on Eurocode 2(2), accounting for the contribution of longitudinal reinforcement in resisting punching shear. The project engineer approved the approach and provided additional longitudinal reinforcement requirements around the column areas to be implemented using CFRP. This solution was agreed upon with a threshold established, beyond which a post-drill fixed shear stud solution would be used. The final design required an average of two CFRP layers per direction around the top of the slab at the columns. Given the efficiency of the ‘top of slab’ application, the installation team progressed rapidly, strengthening between six and eight areas per day.
Further strengthening works
Additional strengthening works were requested in the coming months, including more columns and one transfer beam. The transfer beam required reinforcement due to increased bending moments from the introduction of a new column above it. The project engineers provided data on the additional tensile reinforcement required and CCUK designed an equivalent CFRP strengthening system. The beam required four layers of CFRP applied along its full length and width to support the proposed loads, with the installation completed in just two shifts.
The use of CFRP has made this ambitious project successful by getting the maximum capability from the existing structure.
The future of Granada Studios
In spring 2025, CCUK embarks on the final phase of strengthening. The revitalised Granada Studios will host a world-class members’ club, hotel, restaurant, and bar. The original studio facilities have been modernised by Versa Studios, now offering cutting-edge production and broadcast capabilities, reaffirming its status as Manchester’s premier creative hub for TV, film, music, and digital content.
The transformation of Granada Studios represents a blend of heritage and modernity, with CFRP strengthening solutions playing a crucial role in preserving the structure’s integrity while enabling its exciting new future.
References:
- BRITISH STANDARDS INSTITUTION, CP 114. The structural use of reinforced concrete in buildings. BSI, London, 1969, withdrawn.
- BRITISH STANDARDS INSTITUTION, BS EN 1992-1-1. Eurocode 2. Design of concrete structures – General rules and rules for buildings, bridges and civil engineering structures. BSI, London, 2023.
