Reinforcing concrete model pillars with grouted rock bolts

Efek perbandingan tinggi dan diameter terhadap kekuatan pilar pada pengujian kuat tekan uniaksial dan pemodelan numerik

“…Beberapa penelitian mengenai kekuatan pilar telah dilakukan oleh beberapa peneliti terdahulu seperti penyemprotan pelapis pada dinding pilar untuk meningkatkan kekuatan pilar dengan pengujian laboratorium (Ozturk dan Guner, 2017), pemasangan cincin pada permukaan dinding pilar (Rai, 1981), pemasangan berbagai jenis perkuatan pada pilar kecil di laboratorium (Wojtkowiak, Rai dan Bonvallet, 1985) serta pemasangan rock bolt pada pilar (Ringwald dan Brawner, 1989;Dzakir, 2018;Dzakir, Rai dan Widodo, 2021;Jufrizal dan Kopa, 2021). Selain itu, telah dilakukan pula penelitian efek ukuran pilar terhadap kestabilan bukaan tambang (Greenwald, Howart dan Hartmann, 1941).…”

Analysis of Reinforcement System (Rock Bolt and Shotcrete) Effect on The Pillars Strength in Underground Mining Using Physical Models Testing in Laboratory

“…Based on the triaksial's test, it was obtained three Mohr Coulomb Failure envelopes. Those three failure envelopes latter would be used to estabilish the value of equivalent confining pressure appearing due to the installation of reinforcement system to the pillars (Ringwald and Brawner, 1989;Rai, 1981;.…”

“…Figure 7 shows that the percentage decrease in horizontal displacement (ui) on the pillar wall surface is greater in the pillar with combination of rock bolt and shotcrete reinforcement compared to the pillar with rock bolt reinforcement only or pillar with shotcrete reinforcement only. Equivalent confining pressure is the confining pressure arising because the horizontal displacement on the surface of the pillar wall is detained by shotcrete and faceplate on the rock bolt so that the pillar as if experiencing confining pressure (Ringwald an Brawner, 1989). The equivalent compression pressure value can be determined by inputting Mohr's semicircular line from point σ1 (σc = σ1) up to alluding failure envelope (obtained from the triaxial test) then the left leg of the half Mohr's circle is the equivalent confining pressure value or σ3 ' (Figures 8, 9, 10) that appears due to reinforcement system installation on the pillar (Rai, 1981;Wojtkowiak, Rai, B and onvallet 1985;Das, Sobhan 2014).…”

“…One way to increase the pillar strength is by installing a reinforcement system on the pillar (Hoek, Kaiser, and Bawden, 1995). Problems regarding the reinforcement system on pillars have been investigated by experts, including who conducted research on Rock and Soil Reinforcement and Support, Ringwald and Brawner (1989) who proved that the strength increase experienced by pillar with rock bolt reinforcement strongly influenced by confining pressure which arises because the faceplate attached to both ends of the rock bolt is tightened, Waclawik, Snuparek and Kukutsch (2017) who proved that the bolting support of the ribs is loaded very strongly and its proper design has a decisive effect on the decrease of deformation and strengthening of pillars. Likewise, the results of a research conducted by Ozturk and Guner (2017) show that thin spray-on liners with a thickness of >20% (TSL thickness to core diameter ratio) had a significant influence on increasing the pillar strength.…”

“…In this research, each pillar with different strengths will be given different treatments, namely pillar without reinforcement, pillar with rock bolt reinforcement, pillar with shotcrete reinforcement and pillar with combination of rock bolt and shotcrete reinforcement (Figure 1). Furthermore, each pillar was tested with a uniaxial compressive strength machine to observe the effect of the reinforcement system on the pillar strength (Ringwald and Brawner, 1989). E-ISSN 2541-2116ISSN 2443-2083…”