Brittle failure of hard rock mass

Excavation in the hard, dense, less well-developed rock mass roadway, even if the excavation depth exceeds kilometers or even two kilometers, three kilometers may be self-stabilizing without support. However, if the damage occurs, it will be characterized by local peripheral rupture, sudden slag falling off or sudden convergence, and heavy as a rock burst in a large section of roadway. After the rock burst, the affected roadway may be crowded by the influx of two gangs. Death; can also be expressed as the sudden collapse of the roof or the sudden bottom of the floor.
From the laboratory bursting of specimens where uniaxial compression of rock samples occurs, rockburst is related to the following factors:
(
1 ) homogenization, cleavage is not obvious, microcracks are less, and elasticity is good. The strain recoverable when unloading near the failure is much larger than the rock with unrecoverable strain is easy to rockburst;
(
2 ) The loading system has small stiffness but good elasticity, so that when the rock is damaged, the external system can still apply excessive pressure to the rock, causing rockburst;
(3
) Under the condition of triaxial stress, the higher the confining pressure, the greater the ductility. Once the pressure is suddenly relieved, rockburst may occur;
( 4 ) High-speed loading is easy to cause rock burst.
Rockbursts occurring in production practice are closely related to the following conditions:
1 ) Generally speaking, the greater the danger of deep rock mining, the more severe it is;
2 ) The more severe the geological tectonic stress, the greater the risk of rockburst. Therefore, in the joint part of the large fault skew, the core part of the local fold often has frequent rockburst;
3 ) The improper layout of the mining face, resulting in a highly stressful regional fulcrum pressure zone, such as an isolated or peninsular type of pillar zone, greatly promotes the occurrence of rockburst. It is extremely dangerous to excavate roadways in large pillars of extreme size, and the size of existing pillars (with built-in roadways) is extremely dangerous as they shrink as they are mined.
The analysis of rockburst problems can not be limited to the analysis of the roadway itself, but more importantly, the regional stress analysis and analysis of the regional stress conditions of the rock mass where the roadway is located. This type of analysis can be performed using elastic mechanics methods. Predicting and forecasting rockburst requires the help of experience. Using seismic, microseismic and convergence measurements to monitor the danger zone of the Department is of great benefit to perfecting the forecast.

   Round Downpipe Roll Forming Machine is used for building, it can as rain gutter uses. 

   This machine includes one set decoiler, guiding equipment, main roll forming machine, PLC control system, hydraulic cutting and receving table. 

    It has two cutting modes: flying saw cutting and mould cutting. 


Specifications:

Raw material PPGI or GI
Material thickness range 0.2-0.8mm
Rollers 18 rows
Material of forming rollers 45# steel with chromed
Shaft diameter and mateiral 76mm, material is 40Cr
Material of cutting blade Cr12 mould steel with quenched treatment
Forming speed 12-15m/min(excluding cutting stoping time)
Main motor power 4 KW
Hydraulic station power 3KW
Mode of cutting Hydraulic cutting or flying saw cutting or mould cutting
Control system PLC Frequency Control System with touch screen


Working process:

Working process

Decoiler - Feeding guide - Main roll forming machine - PLC control system - Hydraulic cutting - Receiving table


Pictures of machine:

Round gutter

Round Downpipe Roll Forming Machine


Round Downpipe Roll Forming Machine

Round Downpipe Roll Forming Machine



Training and Installation :
1. We offer installation service local in paid, reasonable charge. 
2. QT test is welcome and professional.
3. manual and using guide is optional if no visiting and no installation. 

Certification and after service:

1. Match the technology standard, ISO producing certification 
2. CE certification 
3. 12 months warranty since the delivery. Board. 

Our advantage:

1. Short delivery period. 
2. Effective communication 
3. Interface customized. 

Round Downpipe Roll Forming Machine

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