Construction process for the implementation of urban utility tunnels in historic centres

摘要

Nowadays, there are many cities that have chosen to build urban utility tunnels (UUTs) in new urban enlargements to house and order the large number of utility networks that should be located in the subsoil. UUTs are a smart and sustainable solution for the future because, in spite of its high initial cost in comparison with the traditional burial system, enable preventive, predictive and corrective maintenance much more agile, less annoying and less expensive. However, only in exceptional cases municipal authorities have opted to use this type of underground constructions as a key element for the renewal and regeneration of the historical centres of their cities. The main reason for this is the constructive difficulty that is added to the higher cost of the initial investment.The origin of this difficulty is mainly motivated because: these urban areas are inhabited and, therefore, utility networks must be maintained in operation during the construction works; the streets are very narrow, which makes the execution of works and the movement of vehicles and machines difficult while at the same time allowing access for people to homes and businesses; and most of the buildings next to the construction site work have poor quality foundations and structures, so opening deep trenches in their proximity implies taking great risks.This paper proposes a construction process to be followed for the implementation of UUTs in historic centres under the premise of maintaining utilities without interruptions during the works and, at the same time, guaranteeing the security of workers, inhabitants, consumers and pre-existing properties. This construction process has been used in the urban renewal works of the historic centre of Pamplona (Spain).