Restoration of the Masonry Arch Bridge Over Jamor River in the National Palace of Queluz

Abstract

The National Palace of Queluz is a reference of Portuguese Heritage and is listed as National Monument since 1910. Its Gardens extend to around 16 acres and have become a reference in European historical gardens due to their complex and harmonious landscaping. However, over the years, the Palace and the Gardens have been severely damaged by a great fire and various floods. In 2012 the management of the Palace and the Gardens was awarded to Parques de Sintra – Monte da Lua and a global restoration project was started. This paper focus on part of that project: the restoration of a masonry arch bridge over the Jamor River that accesses to the Botanical Garden. This bridge was probably constructed between 1752 and 1790 when a lot of construction work took place in the south part of the Gardens. However due to the cyclic floods and other causes, some repair works were made throughout the years, which included the use of concrete in 1967. In this project it was identified a range of pathologies and some severe structural problems, such as the loss of material in the left abutment as well as a crack that crosses the bridge vertically and horizontally. The intervention strategy, based on the minimal intervention philosophy, was defined by a multidisciplinary team and combines structural operations, that include the strengthening of the left abutment through micro piles and the repair and retrofitting of the arch using carbon fibers, with conservation works on originals mortars, bricklaying and pictorial finishing.