Primary roof support design for a large toroidal cavern in Sydney Sandstone is presented. The cavern was constructed with 4m of rock cover beneath Sydney"s Royal Botanic Gardens. Rock reinforcement of pretensioned Macalloy bars and fully grouted rock dowels was designed using a combination of non-linear jointed finite element analysis of the cavern and analytical models to assess the effect of reinforcement on joint shear strength.
Description du plan de support du toit primaire pour une grande grotte toroidale en grès de Sydney. La grotte a ete contruite sous quatre metres de couche horizontale des Jardins Botaniques Royales de Sydney. On a projete du renforcement de roc avec des barres de Macalloy precontraintes et des goujons de roc d"injection complète. On s"est servi d"une combinaison d"un calcul des elements finis qui sont assembles et non-lineaires et aussi des modèles analytiques pour determiner l"effet du renforcement sur la tension unie resultante.
Die konstruktion der haupstuetzen der decke einer großen, kreisringförmigen kaverne im Sydneyer Sandstein wird beschrieben. Die kaverne wurde mit einer 4m starken deckenfelsschicht unter,den Königlichen Botanischen Garten in Sydney angelegt. Die felsverstarkung mit vorgespannten Macalloy-stangen und voll eingegossenen gesteinsduebeln war mit hilfe einer kombination von nicht-linearer gegliederter finiter element analyse der kaverne und analytischen modellen ermittelt worden, so daβ die wirkung der verstarkung auf die schubfestigkeit der verbindung beurteilt warden konnte.
The Sydney Opera House is an important landmark in the historic Rocks area of Sydney. It location on Bennalong Point commands an impressive view of the Sydney Harbour Bridge and it adjoins, Government House grounds and the Royal Botanic Gardens. These features in addition to its exciting architecture and renown as a cultural venue attract numerous visitors "to the Opera House.
Unfortunately, the features which add to the appeal of the Opera House also create significant difficulties in providing vehicle access and in particular car parking facilities have been a problem since the opening of the Opera House in 1973. In response to this difficulty construction of an car parking facility is being undertaken. In order not to detract from the aesthetic appeal of the area the car park is constructed within the Royal Botanic Gardens entirely underground (see Figure 1). A feature of the design is that existing established fig trees above the car park will not be affected by its construction or operation.
The car park will consist of a twin spiral road wrapped around a central intact core containing linking drives and service tunnels (see Figure 2). During construction a toroidal shaped cavern is being created with an outer diameter of 71.2, an inner diameter of 36.4m and a height of 32m. Only 4m cover of Sydney Sandstone exists over the roof of the cavern. The largest unsupported span of 17.4m is significantly greater than has previously been constructed in Sydney Sandstone.
The cavern was excavated in Sydney Sandstone which is generally characterised by: elastic modulus in the range 500MPa to 6000MPa, dominant north-south.
