<p>Shotcrete is a process where concrete is projected or &ldquo;shot&rdquo; under pressure, using a feeder or a &ldquo;gun&rdquo; onto a surface to form structural shapes including walls, floors, and roofs. The surface can be wood, steel, polystyrene, or any ...

An essential characteristic of this stretch is that it has been built under the water table by excavating in very heterogeneous soils, composed of granular soils and rocks of considerable resistance which has created numerous problems during the construction ...

<p>Fibre Reinforced Shotcrete (FRS) is now used together with bolts for ground support in almost every underground metalliferous mine in Australia. Safety and economy have been the primary factors driving the widespread adoption of this system of ground support. ...

<p>A complex rheological model has been used recently at several Austrian tunnel job sites to determine stresses in a shotcrete lining. The raw data are from displacements measurements at the lining contour. The analysis uses a material model based on a thermo-chemo-mechanical ...

There are several different driving forces behind the development of today’s modern robotic equipment. A need for efficiency, safety and economy. Most robotic units will help in this respect, by allowing substantially higher shotcrete output and even set-up ...

The tunnels have been constructed following the NAT method, without top heading and benching, and therefore full face excavated with a total section of 80 m2, and tunnel pulls ranging from 2 to 4 m. The south section of both tubes, excavated in coluvial soils, ...

<p>Numerical methods are increasingly used to predict ultimate limit state stresses in underground structures. Considerable experience has been gained in the UK of design and construction of SCL tunnels in soft ground, particularly under London. The urban ...

<p>The paper gives an overview of the improvements in sprayed concrete technology that have occurred rapidly over the last 10 years, allowing the industry to consider sprayed concrete as a "permanent" structural support.</p>

<p>Given the high deformability requirements of shotcrete in repair, rehabilitation, slope stabilization, ground support, and other applications, the use of fibers in shotcrete is growing. Growing also are challenges surrounding the use of fibers in shotcrete ...

Silica fume was first used in shotcrete in Norway in the nineteen seventies. In the early nineteen eighties the use of silica fume developed in North America, first in Western Canada and then in the United States. Silica fume has been added to both wet-mix ...