Rock Blasting Presplitting

Precision Presplitting: The Basics - Rock Products

May 26, 2016 · The normal presplitting used in quarries and construction projects involves loading a drillhole with a presplit powder, small-cartridge emulsion or dynamite. This is done with little consideration to the rock types and the geologic depositional environment with typical presplit powder loads able to break the strongest of granites and limestones.

PRESPLITTING ROCK IN THE PRESENCE OF A STATIC STRESS …

An electric blasting cap is used to initiate a detonating fuse trunk line which ties the branch of each hole together, Presplitting is useful where cleanJ smooth rock walls are a requisite.

FHWA - Center for Local Aid Support - Publications

Presplit blasting, or presplitting, is used before production blasting to protect the final rock face from damage caused by the production blasting.

Presplitting | excavation technique | Britannica

…met by the technique of presplitting, developed in the United States in the late 1950s. Basically, this technique consists of creating a continuous crack (or presplit) at a desired finished excavation line by initially firing a line of closely spaced, lightly loaded holes drilled there. Next, the interior rock mass…

Blasting a presplit in Granite - YouTube

Feb 19, 2017 · The presplit was drilled 38mm diameter, 4m deep and loaded with 70 gram shear cord, we could not fire it all together as the vibration would have been huge so it was configured to fire three holes...

Study on crack propagation of the CO2 presplitting ...

Abstract CO2 presplitting blasting is an effective method to increase coal seams permeability and improve gas drainage efficiency. During the blasting process, the empty holes in the coal and rock ...

ITEM 208 rock blasting

rock or shale and to construct stable final rock cut faces. Controlled blasting refers to the controlled use of explosives and blasting accessories in carefully spaced and aligned drill holes to produce a free surface or shear plane in the rock along the specified

Pre splitting Granite with det cord - YouTube

Apr 19, 2018 · Breaking rock with Expando and Blasting a pit hole - Duration: 13:11. Demolition Dave Drilling and Blasting 29,690 views. 13:11. Granitte quarry blasting 14 - may - 2012 - Duration: 9:56.

Rock Drilling Tools Function In Open Mine Pit - BD Drill ...

Explosives are employed throughout the mining industry for primary rock breakage. There are a number of controlled blasting techniques that can be implemented to improve highwall stability. These include line drilling, smooth wall blasting, trim blasting, buffer blasting, air decking, and presplitting.

Blasting | Britannica

Blasting, process of reducing a solid body, such as rock, to fragments by using an explosive. Conventional blasting operations include (1) drilling holes, (2) placing a charge and detonator in each hole, (3) detonating the charge, and (4) clearing away the broken material. rock blasting Rock blasting.

Research on the Deformation Mechanism and Directional ...

Affected by the mining activities of the working face, the surrounding rock of the roadway is easily deformed and destroyed. For deep buried roadways, the deformation and destruction of the surrounding rock is particularly prominent. Under the influence of in situ stress fluctuation, 3 −1 103 tailgate of the Hongqinghe coal mine was in a complex stress environment with a maximum stress ...

FHWA - Center for Local Aid Support - Publications

Smooth blasting is a type of controlled blasting thats done either before production blasting, as an alternative to presplitting, or afterwards, either as an entirely different event or as the last delay of the production blast. Table 5 shows recommended borehole diameters, burden, spacing, and explosive charges for smooth blasting.

(PDF) Design of controlled blasting (pre-splitting) in ...

Pre-splitting blasting experiments were carried out to obtain normal pre-splitting blasting parameters such as hole diameter, hole space, gunpowder charge line density, and uncoupling factor.

PROCEDURES FOR BLASTING

Presplit blasting is required on State ROW when the design rock slope is one vertical on one horizontal or steeper and the vertical height of the exposed rock slope exceeds 5 ft. (1.5 m). The contract documents may also specify blasting.

A better way to presplit - Mining & Construction online

Unfortunately at other mines, the opposite is a common experience; presplit holes that take off in different directions, a lot of waste rock that has to be blasted and hauled away at great cost and uneven slope walls that crumble and collapse over time. Large rigs versus ROC

Drilling and blasting - Wikipedia

Rock blasting in Finland Drilling and blasting is the controlled use of explosives and other methods such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut.

Road Cut drilling, presplitting and Blasting - Dykon Blasting

Presplitting is often used to control the highwalls. Millions of pounds of explosives are used every year for this. Dykon Blasting Corp. is a rock blasting contractor and offers drilling and blasting programs for all these highway projects both large and small.