Steel Fiber ilo Tunnel Shotcrete: Rebound, Energy Absorption im Nozzle Distance

Bwebwenato

Juun 15, 2014

Shotcrete ej kōmmane ñan bōk kajoor, jab kajoor in dāpij. Oktak in ej kwalok kin unin an jerbal in tunnel ko kajerbal fiber ko redik, elap joñan im glued bundles.

Ta eo Shotcrete ej aikuji ej bōk kajoor, jab kajoor

Primary tunnel support ej lor juon lemnok eo eoktak jen surface structure ko. Ñe bwidej eo ej rup, layer eo kar spray ej aikuj rup ippān jen an rup ilo jidimkij, innem design parameter eo ej joñan kajoor eo layer eo ej bōk ilo juon deflection. Jerbal in Europe ej kwalok joñan kajoor eo ej bed wot ak joñan an maroñ in bōk kajoor ilo an test ñan EN 14488-3; Jerbal in North America ekkã an jerbal ilo an bin. Ijin ej ijo steel fiber ej bōk jikin: plain shotcrete ej jako an maroñ ilo ien eo ej rup, ilo ien eo juon fiber-reinforced layer ej dāpij wōt juon mõttan in maroñ eo an elikin an rup, eo ej wiaik ien ñan an diwōjlok im kobaiktok jipan.

Rebound: Longer Fiber Rebounds Elaplok

Rebound ej jikin eo ejellok wōnan shotcrete. Men ko rejjab dāpij rej wōtlo k, im shotcrete eo ejjab dāpij ej wōtlo̧k 15% ñan 25%; fiber ej kalaplok jidik kinke fiber ko rej mōkaj ilo nozzle eo. Depakpak ej men eo elaptata an aorōk: 30 mm fiber ej bar jeblak elaplok jen 20 mm. Enin unin an jerbal ilo tunnel ejjab kōjerbal 50 ak 60 mm fiber, meñe fiber eo elaplok an aitok ej emmanlok an anchor ilo theory. joñan eo emman ej 20 ñan 30 mm ippāñ juon diameter epaak 0.55 mm, innem fiber eo ej lor mejatoto eo ilo mejatoto.

20-30 mm ej joñan eo ej jerbal ñan Wet Mix

Wet mix ej kōttāik fiber eo elaplok jen dry mix. Men eo ebin ej pump ilo juon line, innem fiber ko reaitok rej bridge im block ilo bend ko; ilo nozzle eo ej aikuj in jeblak kin mejatoto eo emwij kōmmane. 20 ñan 30 mm ej ekkar ñan elaptata wet-mix robot ko, ippāñ 0.5 ñan 0.75 mm diameter, lelok juon aspect ratio in 40 ñan 55. Elañe joñan an kajoor eo kar kōjjelā kake ej lap, uwaak eo ejimwe ej elaplok joñan, jab fiber eo elaplok: kalaplok 30 ñan 45 kg/m3 ej bōk kajoor eo ilo ien eo ej laplok wōt 4% ak rebound jilu percentage point ko.

25-45 kg/m3 im Design Classes

joñan joñan shotcrete ilo tunnel ej bed ikōtaan 25 im 45 kg/m3. ñan 30 ej kalibubu laajrak in dekā ko remman; 35 ñan 45 ej kalibubu jikin ko rebōd, jikin ko redik im jikin ko relap. Ilōñ jen 45 kg/m3 jerbal ej dikļo k im ri jerbal eo ej kobaik den, eo ej kōmman an kajoor. Enin unin an elōn jikin ko kwalok joñan uno ko rejimwe ak edik aer kajoor. Dose eo elap ej aikuj in kobalok ibben uno ko rej kōmman bwe en diiklok den im kōmman bwe en diklok an mōrā, im juon lale joñan an mōrā im mōrā mokta jen an spray.

Balling: Failure Mode Shotcrete Fears Most

Juon ball in fiber ilo laajrak eo ej nanalok jen an ejelok tokjen: ej kōmman juon jikin ejjelok armij ie im juon jikin eo emõjno eo ej erom juon jikin kōmman crack ñe bwidej eo ej etal. Balling ewōr jilu unin: lelok fiber ilo pein ñan mixer eo, ien eo ejjab jejjet ñan kōmat, im joñan aspect ratio eo elap. Fiber ej aikuj in dāpij ak lelok jen juon kein jerbal eo ejejjet, im kōmman bwe en to an 30 ñan 60 second ko ion concrete eo ejelok men ie. Glued fiber bundle ko rej lukkun kōmman bwe en diiklok jorren eo: row eo ej lelok einwot juon unit, glue eo ej maroñ in rup ilo den ej rup, im kajjojo fiber ej jebel jen dron, im kōkōmanmanlok joñan an jejjet kin elaplok jen 40% jen loose fiber. Enin unin an wet-mix robot ko kōnan glued bundle ko.

Jerbal ippāñ Mesh im Steel Arches

Steel fiber ejjab bōk jikin steel arch ko. Ilo ground classes IV im V arch eo ej letok global stiffness ilo ien eo fiber eo ej letok toughness ñan layer eo make; rej kōmman jerbal ko reoktak jen dron. Fiber emaron, mekarta, bōk jikin mesh eo ilowaan layer eo, jolok men ko rej dāpij, dāpij im likit jerbal im jolok jikin ko rebin itulikin mesh eo. Men eo ekkā an walok ilo jikin eo ej steel arch im fiber-reinforced shotcrete eo ejelok mesh ie. Ej lap tokjen ilo an oktak profile ko, ijo mesh ejjab maroñ in lor juon dekā eo ejjab jimwe ak fiber concrete emaron.

Dry Mix im Wet Mix: Ijo Fiber Balls rej ejaak ie

Rebound ej men eo elaptata an kwalok joñan wōnan ilo tunnel shotcrete, im men eo moktata ejjab fiber eo ak ej jerbal eo. Ilo wet mix men eo emoj an lukkun jeblak ilo ien eo rej pump im accelerator eo ej kobaiktok ilo nozzle eo, innem elaptata lumps ko rej false ball ko rej dāpij ibben don kin paste ko rej rup ilo flight. Dry mix ej oktak: den ej kobaiktok ilo nozzle eo, hydration ejjab jimwe, im fiber ej kobalok ñan ball ko remol ilo hose wall eo im ilo bend ko, im juon ian ko rej itok ñan crown eo ej likit juon void. Kālet wāween eo jen mōttan eo im joñan an depakpak. Ñan juon lining eo ejjab oktak jen 20 ñan 30 mm ilo juon pass, wet mix ej letok juon joñan eo emmanlok; ñan jibañ jidik ien, kōkmman ilo ien eo emōkaj im oktak ko ilo mōttan ko, dry mix ej emmanlok an jerbal im bōk rebound eo elaplok. Wet mix ewōr jilu men ko ie. Depakpak in fiber eo en jab laplok jen juon mõttan jilu in hose eo, innem 50 mm fiber ilo juon 65 mm hose enaj bōbrae. Joñan accelerator ej ļoor an toor ilo dekā eo, elap ej kōmman juon layer eo ebin im edik ej kōtlok bwe en mōrā, im ilo jabdewōt wāween fiber eo ej bōjrak an jerbal. Kōjparok nozzle eo 1 ñan 1.5 m jen ion im spray eo ej jimwe; angled spray ej kōmman bwe fiber ko ren errā ippān mejatoto eo im kōmman juon anisotropic weak plane. Energy absorption ej joñan ilo panel test eo ilo EN 14488-3, im acceptance ej jikin eo iumin load-deflection curve eo jen juon wōt peak value, eo contract eo ej aikuj in kwalok ilo alikar.

Jilu lale bōk ko ilo jikin eo

Bōk shotcrete fiber ej lale jilu men ko: joñan, joñan an jejjet im joñan an bin. joñan uno eo ej lale ilo am kwale juon sample in jikin eo im joñe, ilowaan plus ak minus 10%; joñan wōt juon ilo an kōmman im lale turin mejān, eo ej aikuj kwalok fiber eo ej jelet ilo jimwe im ejelok fiber-free patch ko; kajoor ilo beam test eo kar ņa etan ilo design eo. Ñan model, diameter, joñan im joñan eo ekkar, tunnel im mining section eo ilo steel fiber product page eo ej kwalok joñan im joñan eo ekkar, eo emaron in kobaiktok einwot juon technical annex.