excavation of high stressed hard rock with roadheader

Suitability of Brisbane Rock Conditions to Roadheader Excavation

Rock 2 may be attributed to the fact that Thuro and Plinninger’s 2004 model takes into account the high abrasivity of Rock 2 whereas Copur Ozdemir and Rostami’s 1998 model does not consider the abrasiveness at all. Validation to roadheader excavation.

Roadheaders Designed For Continuous Excavation

MR361 roadheader is an electro-hydraulic part-face cutting machine designed for roadway development and mineral production in coal rock gypsum potash and salt and metal mining. The special attachments and wide array of options such as an integrated swivel chain conveyor coupled with high tramming speed for relo ion make it ideal

Assessment of pick wear based on the field performance of two

A successful excavation of roadheaders depends on the cutting performance and the tool life of and nbsp;conical picks. Tool life is important in terms of wear rate which and nbsp;is affected by different rock parameters such as equivalent quartz content mineral grain size as well as cutting parameters on the cutterhead. In this study analyses among wear rate specific energy advance rate and

Applied Mechanics and Materials Vols. 52-54 p. 16

Mechanical excavation with roadheader EBZ160TY was trialed at work face with hard rock and high ground stress. Work procedure and performance of the roadheader were recorded and analyzed. The results showed that roadheader EBZ160TY with designed excavating strength of 80 MPa presented amazingly good performance in hard rock with strength of

Excavation of High-Stressed Hard Rock with Roadheader

Under the gentle disturbance of roadheader excavation the high ground stress brings the surrounding rock mass to deform into yield and lets the stress/strain energy transform into fracture energy of rock fragmentation.

ROADHEADER IN TUNNELING

SELECTION CRITERIA FOR EXCAVATION METHOD . EXAMPLES – ROADHEADER SELECTION . 7 Complex geology Free access to the face Ability for partial face excavation Gentle excavation Not sensitive against squeezing rock High cutting performance in soft and medium hard rock up to 130 m³/NCH

PDF Rock Mechanical Aspects of Roadheader Excavation

Hard rock excavation by roadheaders presents an interesting alternative to mechanical excavation methods or conventional drill and blast excavation. The very low vibration emissions and precise

Evolution Mechanism of Deformation and Failure of Surrounding

To deeply analyze the failure evolution of surrounding rock during excavation-induced unloading of the high-stress rock mass a multistage failure model was established based on revealed failure patterns. The critical conditions for wing cracks were determined. The slab crack buckling analysis was carried out. The true-triaxial rockburst testing system was used for the miniature model test to

Rock Mechanical Aspects of Roadheader Excavation

ABSTRACT: Hard rock excavation by roadheaders presents an interesting alternative to mechanical excavation methods or conventional drill and blast excavation. The very low vibration emissions and precise profile of a roadheader excavation may effectively contribute especially to projects with sensible infrastructure in the vicinity.

Roadheader solutions in focus - TunnelTalk

The Herrenknecht shaft boring roadheader SBR was developed specifically for mechanized sinking of blind shafts in soft to medium-hard rock. The SBR has been equipped with a roadheader boom and a rotating cutting drum that enables the cutting of variable shaft diameters from 8m to 12m.

PDF Performance of a roadheader under harsh working environment

The factors affecting the performance of 90 kW-shielded roadheader is investigated in detail in a tunnel excavated for Nuh Cement Factory. The first part of the tunnel is horizontal and the second

The performance of a roadheader in high strength rock

The performance of a roadheader in high strength rock formations in excavations. The main rock formation is limestone 72% having In recent years the appli ion of roadheaders in hard

Excavation of High-Stressed Hard Rock with Roadheader - NASA/ADS

Excavation of High-Stressed Hard Rock with Roadheader Zhou Zi Long; Li Xi Bing ; Zhao Guo Yan

Rock Mechanical Aspects of Roadheader Excavation

Rock Mechanical Aspects of Roadheader Excavation Minimizing Risks in RH Appli ion In order to minimize operational ri sks for r oadheader appli ion it is mandatory to perform high quality site investigation which takes into account not only the stability of the rock mass but also puts a focus on the specific rock excavatability.

Zi Long Zhou Scientific.Net

Mechanical excavation with roadheader EBZ160TY was trialed at work face with hard rock and high ground stress. Work procedure and performance of the roadheader were recorded and analyzed. The results showed that roadheader EBZ160TY with designed excavating strength of 80 MPa presented amazingly good performance in hard rock with strength of

Experimental investigation of rock breakage by a conical pick

A previous study of non-explosive continuous mechanized mining of hard phosphate ore using a roadheader indi ed that pre-fracturing the ore generated by excavation-induced high stress concentrations could improve the rock cuttability reduce the wear failure of the cutter and decrease dust production. 27 In this case high stress which is

Experimental Investigation of the Influence of Confining

High geostress is a prominent condition in deep excavations and affects the cuttability of deep hard rock. This study aims to determine the influence of confining stress on hard rock fragmentation as applied by a conical pick. Using a true triaxial test apparatus static and coupled static and dynamic loadings from pick forces were applied to end faces of cubic rock specimens to break them

PDF Influence of intermediate principal stress on rock

Abstract The influence of the intermediate principal stress on rock fracturing and strength near excavation boundaries is studied using a FEM/DEM combined numerical tool. A loading condition of σ 3 =0 and σ 1 ≠0 and σ 2 ≠0 exists at the tunnel boundary where σ 1 σ 2 and σ 3 are the maximum intermediate and minimum principal stress components respectively. The numerical

ROADHEADERS PERFORMANCE OPTIMIZATION

The roadheader production rate and bit costs are controlled by several parameters including: Rock parameters such as rock compressive and tensile strength percent of hard and abrasive mineral content i.e. quartz rock fabric and matrix type and hardness existence of oriented

EVALUATING GEOLOGICAL CONTROLS ON HARD ROCK EXCAVATION NEW

rock removal roadheader hydraulic ram drill and blast mini-mole TBM or a medley of methods . I INTRODUCTION Rock does not equal rock when it comes to cost-efficient excavation of rock in NYC. Proactive geological investigations in the pre-bid and as-built periods can mitigate losses encountered during

High Stress Scientific.Net

Mechanical excavation with roadheader EBZ160TY was trialed at work face with hard rock and high ground stress. Work procedure and performance of the roadheader were recorded and analyzed. The results showed that roadheader EBZ160TY with designed excavating strength of 80 MPa presented amazingly good performance in hard rock with strength of