+86 15516432285

excavation of high stressed hard rock with roadheader

excavation of high stressed hard rock with roadheader

Excavation of High-Stressed Hard Rock with Roadheader ...

Drill and blast method becomes unfavorable for deep mining of hard rock. 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

(PDF) Rock Mechanical Aspects of Roadheader Excavation

The lifetime of the present pick tools in higher rock strength and abrasivity is the major limiting factor for roadheader use in hard rock [2] – see Fig. 2. But also the geometric configuration ...

Roadheaders for hardrock - Sandvik Mining and Rock Technology

May 09, 2017 · Sandvik MH621 hard-rock miner is an electrically powered and crawler-mounted roadheader that is engineered to excavate roadways and galleries in strong rock formations. This heavy-duty machine has a powerful transverse cutter head mounted on an extremely robust telescopic cutter boom. It is designed to excavate rock with high compressive strengths.

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

(PDF) Performance of a roadheader under harsh working ...

from this harsh working environment and. performance of a partial face machine such as. roadheader highly depends upon the abilities of. operators (Breeds and Conway, 1992). As a. concluding ...

Numerical simulation of optimum mining design for high ...

Sep 01, 2012 · Thus the raw rock ore becomes easier to be fragmented, which provides advantageous conditions for roadheader to cut high stress hard-rock. It is worthy noting that there is a large difference in effective utilization of deep ground pressure between horizontal and vertical excavation directions.

Shaft Boring Roadheader (SBR) - Herrenknecht AG

The Shaft Boring Roadheader (SBR) was developed for the mechanized sinking of blind shafts in soft to medium-hard rock with up to 120 MPa. For the efficient excavation of the rock, the SBR has been equipped with a roadheader boom and a rotating cutting drum. This allows the creation of variable shaft diameters between 7 and 12 meters.

The Importance of Research on Alternative and Hybrid Rock ...

Jan 27, 2017 · 高达12%返现 · Current methods of mechanical excavation of rock are limited in regard to the material which can be extracted economically. The use of roadheaders with pick tools has the advantage of high flexibility in form of turn off radii down to 1 m but is limited by rock strength to figures below 150 MPa UCS.While mechanical rock excavation machines with disc cutters can

On the Dead-Center Positions of Stephenson Six-Bar Linkage ...

Excavation of High-Stressed Hard Rock with Roadheader p.905. Detection of a Crank in the Stephenson-Ш Six-Bar Linkage p.909. On the Dead-Center Positions of Stephenson Six-Bar Linkage p.915. Parameterize the Center of the Trust Region for Solving Quadratic Interpolation Models ...

Detection of a Crank in the Stephenson-Ш Six-Bar Linkage ...

Excavation of High-Stressed Hard Rock with Roadheader p.905. Detection of a Crank in the Stephenson-Ш Six-Bar Linkage p.909. On the Dead-Center Positions of Stephenson Six-Bar Linkage p.915. Parameterize the Center of the Trust Region for Solving Quadratic Interpolation Models ...

(PDF) Performance of a roadheader under harsh working ...

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 ...

Roadheader - creg-germany

Minimum turning radius of the maglev train is 75m. To greatly reduce the disturbance above ground in the dense residential area, CREG roadheader was used for excavation.  Data: Applied Model: CTR323. Tunnel section: 12.86m wide * 9.66m high. Tunnel length: 162m. Construction method: Roadheader. Excavated material: Hard rock. Rock hardness ...

(PDF) Past, Present and Future Advancement in Rock Cutting ...

Especially for hard rock excavation, we . ... varieties of roadheader, Roadheaders were . ... development heading which is 4.1 m high by . 5.5 m wide, ...

SANDVIK TUNNELING ROADHEADER MT720 HARD ROCK!

The Sandvik Tunneling Roadheader MT720 is an extremely powerful boom-type roadheader of the 100 tons class and has proven its unique transverse cutting technology in hard rock applications worldwide. This machine has an extended field of operation for mechanized tunneling in hard and

Assessment of pick wear based on the field performance of ...

Jan 04, 2020 · A successful excavation of roadheaders depends on the cutting performance and the tool life of conical picks. Tool life is important in terms of wear rate which 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 cutter ...

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 ...

Analysis of rockburst triggered by hard rock fragmentation ...

Feb 01, 2020 · As a widely used excavation machine, a roadheader is preferable for cutting low to medium strength rock but is unsatisfactory for extremely hard rock because of rapid cutter wear-out and has low operation stability in shallow excavation (Ergin and Acaroglu, 2007, Yang et al., 2015, Dewangan and Chattopadhyaya, 2016, Dewangan et al., 2015).

Experimental Investigation of the Influence of Confining ...

Sep 02, 2017 · 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

Assessing fracturing mechanisms and evolution of ...

Assessing fracturing mechanisms and evolution of excavation damaged zone of tunnels in interlocked rock masses at high stresses using a finite-discrete element approach Deep underground excavations within hard rocks can result in damage to the surrounding rock

Examination of Geological Influence on Machine Excavation ...

A combined geological and rock mechanics approach to tunnel face behaviour prediction, based on improved understanding of brittle fracture processes during TBM excavation, was developed to complement empirical design and performance prediction for

China Railway Engineering Equipment Group Co - Roadheader

Roadheader. Introduction: The cutting power of CREG’s roadheader CTR323 is 323 kw. The maximum cutting range is 8 m wide × 7.5 m high. The overall machine weights 130 t. The most cost-efficient way is to cut rocks with UCS less than 60 MPa. Project Facts.

[PDF] A Model to Predict The Performance of tunnelling ...

Within NATO TU-Excavation Project supported by Science for Stability Programme, a detailed research study was carried out using a numerical modelling software (Franc 2D/L) and a small-scale rock cutting rig. Experimental samples were prepared using cast plaster and concrete blocs, which were later stressed by the aid of hydraulic pistons.

UG Mechanical Excavation | PDF | Coal Mining | Tunnel

Rapid excavation equipment (Mobile tunnel miners,Tunner borers, raise borers, and shaft sinking rigs) for soft to medium hard and hard rocks) Surface: Rippers for very compact soil, coal, and weathered or soft rock. Bucket wheel and cutting head excavators for soil or coal. Augers and highwall miners for coal.

Advanced Rock Tunnelling Engineering Solutions | WSP

A roadheader is used as a mechanized method of cutting that has more precise cutting, less vibration, and no overbreak. Recent developments allowed the excavation of rock tunnels in very hard rock. The basic cutting tool is a very large milling head mounted on

Roadheader Excavation Performance - Geological And ...

Aug 25, 1999 · During the last few years in mechanical excavation, problems have occured also connected with the accurate prediction of excavation performance and tool wear in soft and hard rock. Every now and again problems have been encountered leading to high bit consumption and low cutting performance of roadheaders.

MH620 ROADHEADER FOR HARDROCK SANDVIK MINING

Sandvik MH620 hard-rock miner is an electrically powered and crawler-mounted roadheader that is engineered to excavate roadways and galleries. This heavy-duty machine has a powerful transverse cutter head mounted on an extremely robust telescopic boom.

SANDVIK MT720 ROADHEADER - Sandvik Mining and Rock

Feb 26, 2019 · rehabilitation of existing tunnels and excavation of underground caverns are just a few examples where these machines have demonstrated their great flexibility. Our Sandvik MT720 is an electrically powered and crawler-mounted boom-type roadheader which is engineered to cut hard and abrasive rock beyond 120

A new method for roadheader pick arrangement based on ...

Nov 17, 2021 · Therefore, the roadheader with a transverse cutting head is mainly used for higher hardness rock excavation [2, 3],as shown in Fig 1. Picks are installed in the pick boxes and cutting into the rock in sequence during the cutting head rotation, and the rock is broken by the combination of compression and shear [ 4 ].

(PDF) Past, Present and Future Advancement in Rock Cutting ...

Especially for hard rock excavation, we . ... varieties of roadheader, Roadheaders were . ... development heading which is 4.1 m high by . 5.5 m wide, ...

Advanced Rock Tunnelling Engineering Solutions | WSP

A roadheader is used as a mechanized method of cutting that has more precise cutting, less vibration, and no overbreak. Recent developments allowed the excavation of rock tunnels in very hard rock. The basic cutting tool is a very large milling head mounted on

Experimental and numerical investigation of roadheader for ...

Mar 31, 2020 · Roadheaders are one of the most widely used machines for fast roadway constructions in soft to medium‐hard rocks owing to their advantages, such as high advance rates, good mobility, and versatility. 1, 2 However, when breaking hard and abrasive rocks, the cutters of a roadheader are subjected to serious shock, high forces, excessive wear ...

Comparative Study of the Excavation Damage and Rockburst ...

Dec 09, 2020 · The rock mass failure induced by high in-situ stresses during the excavation of deep diversion tunnels is one of the key problems in the construction of the Jinping II Hydropower Station. Based on the results of acoustic wave tests and rockburst statistical analysis conducted, this study focuses on the excavation damaged zone (EDZ) and rockburst events in the Jinping II diversion

Tunnel Construction Overview

– Roadheader excavation • or fully mechanised options using ... Bored or Driven Tunnel. 7 • Limited rock deformations around the tunnel during the stress re-distribution phase after the tunnel advance are allowed. • Leads to an adaptable, economic support system. ... TBMs are classified as hard rock or soft ground machines.

Stability Analysis of Surrounding Rock of Large Section ...

Oct 08, 2021 · In order to study the stability of deep surrounding rock during the excavation of new main shaft in Xincheng gold mine, a construction method suitable for large section ultradeep shaft is proposed. A series of analyses were carried out in this study, including the in situ stress test, stress response of surrounding rock disturbance, deformation and failure characteristics, and numerical ...

Analysis of Roadheader for Breaking Rock Containing Holes ...

Deep underground mines have high energy consumption due to the need to overcome the confining pressure. This study investigates the characteristics of the roadheader used for breaking rock containing a different number and size of holes under different confining pressures. A series of simulations were conducted using the LS-DYNA software to study the cutting torque, thrust force, specific ...

Overcoming squeezing in the Yacambú-Quibor tunnel,

used hard rock Tunnel Boring Machines (TBMs) since initial site investigations at the ... This section of the tunnel was constructed with excavation by means of a roadheader of a modified horseshoe shaped tunnel as shown in Figure 7. Support consisted of high-strength ... Figure 9: Installation of a circular lining in heavily stressed rock. The ...

Determination and Engineering Practice of Unsupported Roof ...

Apr 24, 2021 · In order to determine the reasonable empty roof distance during roadway excavation, a mechanical model of the direct roof rock beam was established, and the relationship between the direct roof tensile stress and the empty roof distance was obtained. According to the criterion of roof stability, that is, the tensile stress of the roof does not exceed the tensile strength, the expression of the ...

What is Road Header? - Definition from Trenchlesspedia

The cutting head on the roadheader can be general purpose such as rotating drum or jaw like buckets or with special features such as jack hammer with spikes. Pipe jacking is a trenchless construction method that uses roadheaders to cut through differing geological conditions such as loose soil or hard rock.