Design of Shotcrete Support from the Rock Mechanical Viewpoint
When designing tunnel support the key question is to determine the loading conditions resulting from the deformation of the rock mass during and after excavation. Principle views are given...

Design and Uses of Reinforced Shotcrete in Underground Projects in Canada
The first use of steel fibre reinforced shotcrete (SFRS) in Canada was using the wet-mix process in the support of deteriorated ground in 80 year old railway tunnels in the Fraser Canyon,...

Design and Application of Integrated Shotcrete Linings for Underground Openings in Weak Rock Masses
Tunnels and caverns excavated in weak rock masses require special consideration in terms of shotcrete lining design. Shotcrete as a support medium for weak rock provides major benefits...

Reduction of Head Losses in Tunnels by Means of Shotcrete
Head losses in blasted rock tunnels conveying water to hydropower stations often significantly reduces the energy production in the plant. Typical values on the head losses in tunnels...

Guidelines for Shotcrete Support in Hard Rock
The writer is working on a handbook on shotcrete in hard rock. The work is sponsored by the Swedish Power Board, Development Division. The main contents are: Choice of shotcrete support...

Technical Note: STC-40 Shotcrete Adhesion In Situ Tester
It is essential that the shotcrete when reinforcing the rock mass achieves a good adhesive bond to the rock surface. The strength of that bond can be controlled by pull out testing either...

Summary—Theme 2—Shotcrete Mix Design—Shotcrete Additives

Wet Mix Shotcrete Used in Subsea Tunnel Environments
To reject the claim that the use of accelerator in shotcrete reduces the compressive strength with time, lately cored samples were taken from an 18 to 19 years old concrete. A wet mixed...

Application of the Wet Shotcrete System Top Shot in Tunneling—Experiences, Evaluation and Comparison

Guidelines for Shotcreting and Current Development in the Wet-Mix Technique in Finland
Guidelines for shotcreting were written based on the literature survey and shotcreting trials. During shotcreting trials existing Norwegian and Middle-European wet-mix shotcreting concepts...

Austrian Guideline and National Report on the Use of Shotcrete
The purpose of this guideline is the standardization of quality and a uniform procedure for the production and testing of shotcrete from the technical and engineering point of view. In...

Practical Considerations on the Use of Additives for Shotcrete
Shotcrete is mostly used today for securing rock: in this capacity, it has solved many problems and has become a necessary aid. However, thedegree of utilization of the method is still...

The Influence of Water Glass on the Technological Parameters of Shotcrete
Shotcrete used in tunneling must follow a clearly defined early strength development in order to comply with stresses from rock deformations and drilling and blasting. Accelerators are...

Shotcrete Tests at the Fish Ecca Tunnel
The Fish-Ecca Tunnel is situated in the Eastern Cape and forms part of the Lower Fish Irrigation Scheme. About 25% of the 5032 m tunnel had to be lined with shotcrete. Between February...

New Advances in Shotcrete Additives: The DELVO System
The DELVO system is a two component, nonchloride chemical system developed to control the dynamics of cement hydration. Concrete, treated with the DELVO system, can be kept in a plastic...

Advances in Dry Shotcrete Technology by Means of Microsilica
During the last decade microsilica has been increasingly used to improve both wet and dry mix shotcrete. In the traditional dry process microsilica is blended in the dry mixture. Since...

Summary—Theme 3—Fibre Reinforced Shotcrete

Use of Steel-Fiber Reinforced Wet-Mix Shotcrete in Extreme Rock-Bursting Conditions
If the stresses close to tunnels or caverns exceed the capacity of the surrounding rock, rock-bursting might start. When tunneling in such rock conditions the need for a safe, quick and...

Use of Long, Variable Length Steel Fibres in Shotcrete
Steel wires are cut to fibres in a shotcrete nozzle and directly incorporated in the ejected shotcrete. Long and variable length fibres can be used. The fibre material is better utilized...

Steel Fibre Reinforced Wet Shotcrete with Very High Deformation Capacity
Tests have been carried out under site conditions in Norway where the performance of 40 mm long DRAMIX fibres was compared with normally used 30 mm fibres. The fibres were mixed into the...

 

 

 

 

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