Evolution of Fiber Reinforced Shotcrete

The concept of reinforcing shotcrete with discrete, disominous steel fibers was developed by the Battelle Research Corporation in the USA in the early 1970s.

Shotcrete Design and Construction for the Stave Falls Project Power Tunnels

BC Hydro has recently completed construction of a replacement power plant at Stave Falls, near Mission, British Columbia. Two new power tunnels were constn1cted to carry water from the intake to the new powerhouse. The crown, walls, and invert of the power tunnels were fully lined with steel fiber-reinforced shotcretc for the primary pur­pose of reducing the hydraulic roughness of the drill and blast tunnel surfaces. Shotcrete was also used for the geometric transition from the horseshoe-shaped, shotcrete-lined tunnel to the circular steel lining.

Shotcrete for Underground Support in Brazil

Shotcrete has been used in Brazil since the 1950s, mainly in minor works of slope stabilization and repairs in concrete structures. It was only in the 1960s that it started to be used in underground work. The Furnas Hydroelectric Project had some sections of its diversion tunnels, where the ground was a highly fractured and weathered quartzite, lined with steel bar reinforced shotcrete. The good per­formance in Furnas led many other hydroelectric projects to adopt shotcrete lining in their tunnels, replacing previously specified cast concrete.

Shotcrete Applications at Northparkes E26 Mine

Shotcrete was used extensively during construction of Northparkes E26 Underground Mine, Australia’s first block cave mine. Applications for the shotcrete included ground support, ground control, construction, safety, protection of equipment and remedial repairs. This article details the various uses for the 16,700 m3 (22,000 yd3) of shotcrete applied at Northparkes, the experiences gained during con­struction, and discusses whether the design expectations have been achieved.

Estimating Volume of Shotcrete for Mining Applications

Traditionally, there has been a rather ad hoc attitude to­wards technical supervision of mining engineering ground control programs, to the extent that the preparation and enforcement of specifications has not been a major issue. In certain locations, however, the dominant use of con­tracting companies to provide mining-related services has meant that structured specifications are needed to ensure the high quality of the end-product. This is perhaps par­ticularly the case with shotcrete (1) now that more and more mines are using the process and product to enhance the ground control regime within the mine.

Shotcrete Reinforcement

Before the 1970s, shotcrete was reinforced either with conventional reinforcing steel welded wire mesh fabric, or in some in­stances with chain-link mesh or even chicken mesh. In the early 1970s the con-Dr. D.R. (Rusty) cept of steel fiber reinforced shotcrete

Rehabilitation of Sanitary and Storm Sewers Using Shotcrete

The infrastructure of the United States is crumbling above, below, and around us. A considerable segment of the public and private engineering community is currently engaged in solving a geo­metrically increasing problem with geometrically decreasing funds. The problem is often compounded since maintenance of public works facilities must be paid for using public funds. This article will introduce a process for solving these problems that has actu­ally been around for many years-the process of using shotcrete or gunite to rehabilitate old, damaged, or otherwise substandard existing sewers.

Dry, Pre-mixed Shotcrete Supply for Tunnels and Mines

Tunneling and mining projects use shotcrete primarily as a means of ground support. Immediate application of shotcrete provides stability of the working face, prevent­ing loose rock from initiating movement and thus permit­ting incremental advances of underground openings even in the worst ground conditions (type V rock) or clays.