01
Open Pit Bench Blasting
Pattern, charge and delay design to the production target; controlled bench shots.
Drilling & Blasting Engineering
Drilling & blasting engineered for the rock: one team from design to firing
Blast pattern design, drilling, charging and delay firing for open pits, tunnels and excavation sites; every shot is verified with vibration monitoring and fed back into the next design in a closed loop.
Open Pit + TunnelDrilling & blasting capability in both settings
Electronic / NonelDelay initiation systems
kg/m³Powder factor designed to the target
PPV MonitoringMeasurement and reporting on every shot
Service Scope
From permits to firing: twelve service lines
The full chain — permits, technical specifications and procurement through site execution, measurement and reporting. Every project is designed to its rock mass, surroundings and fragmentation target; services are available individually or turnkey.
02
Gallery / Tunnel Blasting
Precise advance through face design, cut layout and perimeter hole control.
03
Excavation & Foundation Works
Low-vibration, small-diameter controlled shots near settlements and infrastructure.
04
Blast Design & Modelling
Fragmentation, muckpile and vibration prediction; closed-loop optimisation with post-blast analysis.
05
Vibration Monitoring & Reporting
PPV and air overpressure measurement, standard-based assessment and a signed report.
06
Drilling Service (Rock Drill / DTH)
Holes true to pattern with measured deviation; quality control through drill logs.
07
Explosive Bolt Design
Custom bolt and nut design that releases diversion tunnel gates within seconds in an emergency.
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Engineering Tools & Software
We build project-specific calculation tools and software for blast design, powder factor and cost estimation.
09
Specification & Procurement Consultancy
Technical specifications, contractor agreements and acceptance criteria for explosive procurement by public and private organisations.
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Permits & Licensing
Explosive purchase and use permits; regulation-compliant follow-through from application file to permit delivery.
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Training & Field Support
Crew training on storage, charging and firing practice; on-site supervision during the first shots.
12
Underwater Drilling & Blasting
Specialised blasting for harbours, cofferdams and underwater excavation using waterproof charges and delay firing.
Method & Design
Milliseconds govern the rock
Move your cursor over the panel — in this 4-row × 7-hole bench model, initiation starts at the free face and steps back row by row. As the front row throws rock forward, the rows behind break to the new void: vibration drops, fragmentation and muckpile shape stay under control.
Delay Firing — 3D Bench Model
Move your cursor over the panel
- 01Site survey and designRock unit, discontinuities and surroundings inventory; pattern, charge and delay plan.
- 02Drilling and controlDrilling to pattern; hole depth, deviation and water condition are logged.
- 03Charging and stemmingCharge placement to design, stemming and a hook-up checklist.
- 04Delay firingSequenced initiation with electronic or nonel systems; minimum charge per delay.
- 05Measurement and reportingPPV records, muckpile and fragmentation analysis; results feed the next design.
Specialised Blasting Application
Underwater drilling & blasting
Harbour and berth deepening, excavation inside cofferdams and removal of submerged rock levels are done by delay-firing holes drilled underwater and loaded with waterproof charges. The water column acts as stemming — the design goal is to break the rock at the planned level while keeping water shock and scatter within limits.
- 01Bathymetry and bed profileWater depth, rock-bed profile and excavation level are surveyed; hole depth and pattern follow.
- 02Underwater drillingCasing-guided drilling from a pontoon or platform; level and deviation logged for every hole.
- 03Waterproof chargingCharges and detonators rated for water pressure and sleep time; circuit continuity tested underwater.
- 04Delay firingThe water column acts as stemming; the delay plan limits water shock and heave.
- 05Monitoring and surveyIn-water pressure and vibration measurement; post-blast depth survey verifies the excavation level.
Custom Engineering
Explosive bolt: a design that releases the diversion gate within seconds
When a diversion tunnel must discharge in an emergency, the gate has to open without delay. Mechanical release mechanisms can seize under load at that moment; an explosive bolt instead uses a small charge placed inside the nut to cut it at a designed section and free the bolt instantly.
DTEX designs these bolts: the shear section for the gate load, the charge cavity inside the nut, the charge weight and the firing circuit are calculated per project — and verified with a full-scale trial shot before going to site.
- 01Gate and load analysisGate geometry, water load and the tensile force per bolt are determined.
- 02Bolt–nut geometryThe cavity machined into the nut, the shear section and the notch geometry define the plane where separation will occur.
- 03Charge and detonator placementThe smallest charge that defeats the shear section is selected; detonator and firing line are routed out through the nut.
- 04Verification by trial shotA full-scale assembly is fired on steel plate of the same thickness; separation at the designed section is inspected and confirmed.
- 05Installation and commissioningTorque-controlled installation on site, circuit continuity testing and safe handover of the firing circuit.
Preliminary Assessment
Try the powder factor yourself
Adjust the pattern and charge to pre-assess the explosive consumed per cubic metre of rock (powder factor).
q = Q / (B · S · H)
0.52kg/m³
Rock volume per hole: 105 m³
0lighttypical open pithard rock1.5
This calculation is for preliminary assessment. The final pattern is designed on site to the rock unit, discontinuities, hole diameter and fragmentation target.
Engineering ToolsInternational Framework
Design and monitoring follow recognised international standards
Blast-induced vibration is assessed and reported against whichever of the standards below fits the project geography, structure type and employer specification.
USBM RI 8507
Structure response limit curves
Frequency-dependent PPV limit curves; the common reference for residential structures.
OSMRE 30 CFR 816.67
Blasting control criteria
Distance-based maximum allowable PPV and scaled distance application rules.
DIN 4150-3
Vibration effects on structures
Short-term vibration thresholds by structure type and frequency band.
BS 7385-2
Building damage assessment
Setting cosmetic damage thresholds for transient vibration.
ISO 4866
Measurement and evaluation principles
Sensor placement, recording and data processing principles.
EN 13630 / EN 13763
Explosive product standards
Conformity requirements for safety fuse, detonators and initiation systems.
Field Media
Frames from the operation
Videos play on hover; every frame enlarges on click. All footage is from the DTEX archive.
Which permits are required for blasting?
An explosive purchase and use permit, certified blaster qualifications and a site-specific safety plan are required. After the project survey we provide you with the permit list and its timeline.
Can blasting be done near settlements?
Yes — a structure inventory is compiled, site constants are established with a trial shot, and the charge and delay design is set to the limit of the selected standard. Every shot is recorded with a vibration monitor.
Why does delay firing matter?
When holes fire in sequence at millisecond intervals, the charge detonating at any instant is smaller; vibration drops, rock is thrown forward in a controlled way and fragmentation improves.
How is flyrock prevented?
Through correct bottom charge, adequate stemming, pattern discipline and shot direction control; blast mats are used where needed and safety distances are defined in the site plan.
Can fragment size be guaranteed?
Fragmentation is a function of rock mass, pattern and powder factor. The target size is set to crusher/screen capacity, measured with post-blast image analysis, and the design improves with every shot.
Do you obtain the explosive permits?
Yes. We run the explosive purchase and use permit process in line with national legislation and the international rules the project is subject to — from preparing the application file to delivery of the permit.
What do you prepare for specifications and contracts?
For explosive procurement by public and private organisations we prepare regulation-compliant technical specifications and contract annexes covering needs definition, product and equipment characteristics, acceptance criteria, safety and storage conditions and contractor obligations.
What does training and field support cover?
It spans the process from explosive supply to the final application on site: crew training on storage and transport rules, charging and firing practice, safety instructions and record keeping; on-site supervision during the first shots and ongoing consultancy afterwards.
How is the charge protected in underwater blasting?
Because the hole is full of water, waterproof charges and detonators rated for water pressure and sleep time are used. Circuit continuity is tested underwater, and the time from charging to firing is limited in the design.
What about effects on marine life?
The impact is assessed through the in-water pressure wave (overpressure). The delay plan reduces the charge firing at any instant, damping measures such as bubble curtains are applied where needed, and measurement records are reported.
What is an explosive bolt and why use one?
Diversion tunnel gates must be released within seconds in an emergency. Mechanical release mechanisms may not operate reliably in that window; in an explosive bolt, a small charge placed inside the nut cuts it at a designed section and frees the bolt instantly.
How is an explosive bolt verified?
Before installation, a full-scale assembly is mounted on steel plate of the same thickness and trial-fired. Separation at the designed section, absence of plate damage and fragment scatter contained by the blast mat are inspected and confirmed.
Can I get only drilling or only monitoring?
Yes. Drilling, blast design and vibration monitoring services are also available separately.