DESIGN, CONSTRUCTION AND OBSERVATION OF THE BEHAVIOUR OF MRAZOVKA TUNNEL IN PRAGUE, THE CAPITAL OF THE CZECH REPUBLIC

摘要

The construction of the Mrazovka automobile road tunnel, a part of the city ring in Prague, is currently one of the most significant transport constructions in the country. Made up of two three-lane tubes, the tunnel divides into a two-lane tunnel and a one-lane ramp. The three-lane tunnel cross-section area is 165.0 m~2, while the profile area of the fork division point is 163.3 ― 324.2 m~2. Construction of the tunnel commenced on December 21, 1998. The tunnel will be opened in December, 2002. The driven tunnel is. constructed using the New Austrian Tunnelling Method (NATM) in very complicated geo-technical conditions in a densely built-up area with a minimal overburden. This article describes the spatial and construction design of the tunnels, the proposed tunnelling method, the methods of securing the above-ground structures, the experiences from excavation, and the results of measurements and monitoring during the construction of driven underground structures.