100 Bishopsgate Demolition and Enabling

Project Scope

100 Bishopsgate is the redevelopment of a 2 acre site at the junction of Bishopsgate and Chamomile Street in the heart of the City of London.

The new development entails the construction of a 40 storey office  tower and a  7 storey low rise office building which incorporates a retained façade on St Helens Place.

To facilitate the new development 5 No. existing structures of various construction dates and type that were present on site were required to be demolished down to top of existing basement slab level. The demolition works were undertaken by a combination of mini machine and large machine demolition with the assistance of a tower crane.

This was then followed by a substructure enabling works package which included archaeological excavation investigations and temporary works to prop the existing basement retaining walls to allow for pile probing to both bearing and secant wall piles followed by the installation of high level piling platforms and access.

Project Challenges & Solutions

Approvals & Party Wall Awards – Keltbray were appointed under a pre demolition services agreement to obtain all required approvals including party wall approvals  ahead of commencement of works on site which enabled an accelerated delivery programme for the on site works.

UKPN Substations – The existing site contained 6No. existing sub stations 3No. of which were networked, these had to remain in operation until diversion and network reinforcement works were completed which would be post demolition. To maintain the 3No. network substations Keltbray had to install extensive temporary weathering and protection to allow the demolition and pile enabling works to be completed with the UKPN assets and associated cable network remaining in position until a later phase of the works.

Advanced Archaeology/Underpinning – Advanced archaeological excavation works and underpinning were undertaken with MoLA attendance concurrently with the structural demolition works to discharge planning conditions early within the development to reduce risk and ensure compliance with the rapid enabling works programme.