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The use of shotcrete in Australian underground mining – A contractors perspective
Published in Ernesto Villaescusa, Christopher R. Windsor, Alan G. Thompson, Rock Support and Reinforcement Practice in Mining, 2018
The ability of steel fibre reinforced shotcrete to deform and carry load after cracking is the key to the usefulness of the product. “Toughness” is the term given to describe the post-crack performance of the material.
A systematic approach for the analyses and design of jointed rock mass slopes against wedge and toppling failures: a case study of the stability of the abutments of the bridge across the Chenab River
Published in International Journal of Geotechnical Engineering, 2021
Srinivas Mantrala, A. K. Verma, T. G. Sitharam
Irrespective of the requirement, minimum three rows of rock bolts were provided in reality. Three to five rows of passive rock bolts of 32-mm diameter and 11.5 or 8.5 m length were installed in 100-mm diameter boreholes perpendicular to the slope. The spacing of rock bolts is generally 2.5 m and in some wedges reduced to 1.5 m. In case of the slope immediately below the foundation at S60, prestressed bar anchors of 625 kN capacity and 33 m length are provided in five rows. The spacing of anchors is 2.5 m in each row. In case of the slope immediately below the foundation at S50 prestressed cable anchors of 980 kN capacity and 40 m length are proposed in nine rows. The spacing of anchors is 2.5 m in each row. The prestressed anchors can be restressed if required. To ensure the immediate stability of the excavated slopes, immediately after geological logging of the slopes, 100-mm thick steel fibre reinforced shotcrete was applied in two layers of 50 mm each.
Practical shotcrete rock reinforcement for hard rock openings
Published in HKIE Transactions, 2018
For some cases or in vertical stress greater than 8 MPa (or rock cover < 300 m) ground conditions, it would be found that excessive structural shear force of the shotcrete liner at the opening (mostly at the shoulders, mid-location of crown or mid-location of wall) may be noted. One of the methods utilising shotcrete with steel reinforcement such as steel wire mesh or steel bar reinforcement, or using steel fibre reinforced shotcrete could be introduced. Attention is drawn that if the opening is constructed in very high in-situ stresses rock conditions or near/in the tectonic plate earth crust, separate assessment and modelling should be conducted and thus SRR approach may not be suitable for the design.