GeoBlast has available a number of tools designed to control and monitor variables that can affect the results of the mining or civil engineering activities.
Monitoring of blast induced vibration in mining activities (Particle Velocity, Peak frequency, Dominant Frequency). These services are offered in both closer and remote field, and oriented to damage control at bench and / or slope level or over tunnels, pillars, slabs or sensitive infrastructure.
We offer services in ambient vibration monitoring and assessment in the case of construction projects and other non mining related industrial activities where blasting is required and where direct and indirect impact of blasting must be evaluated, whether is manifested as damage to surrounding infrastructure, induced negative externalities on residents (human perception) or disturbance as an environmental impact assessment (protected fauna, national monuments, etc.). As a response to this reality our offer includes monitor and control of the environmental impact caused by vibrations and waves of air pressure and if necessary, redesign of the blasting program to mitigate its effects.
Mining activities produce a series of emissions to the atmosphere, in different ways, such as solid (dust, fly-rock), gas (pyrometallurgy, vehicle exhaust, gas fumes during some specific processes), noise (blasting, machinery) and aerial wave. GeoBlast offers its experience in assessment of blasting and drilling impacts and in the design of appropriate measures of mitigation.
The seismicity analysis of a particular area is intended, in simple words to determine the seismic risk an engineering work is exposed to. With this in mind, gene-seismic zones associated to the area of work are first identified and acceleration maximum values are estimated. In general terms values for an earthquake of operation and maximum probable intensity earthquake are estimated. This estimated information is also useful to determine the margins of response for rocks or solid ground.
Using various techniques, such as seismic refraction, the application of tomographies, etc. is possible to characterize the rock mass, either for exploration, damage control or for construction projects where the dimension of specific requirements its necessary, such as the location of foundations. These techniques, separately or in combination, can increase the level of knowledge in relation to geomechanical properties of interest, depth of strata present, and so on.
Seismic Refraction Tomography The field operation for the execution of a seismic refraction profile consists in installing a line of geophones on a surface reaching an extension of 3 to 4 times the depth under investigation. By means of knocking on a plank or board close to the ground or by using explosives buried close to the surface (1 meter), seismic waves are generated at various points along the line of sensors (geophones). The seismic energy propagates through the bedrock and is detected by the sensors. Time of travel of seismic waves between every seismic source and every geophone is recorded and processed. An inversion analysis of the data is made, obtaining as a result the spatial distribution of the seismic wave velocities in the section beneath the sensor lines.
Seismic Reflection Tomography In the seismic reflection surveys, the analysis is centered on the seismic energy that is reflected in the most prominent interfaces. The distribution of geophones, compared to the seismic refraction method, is denser. The seismic reflection method is a very sophisticated version of the echo soundings used by submarines, ships, and radar systems as huge depths are covered. Besides examining the time of arrival, the seismic reflection extracts information on the bedrock and soils based on the amplitude and form of the movement seismic reflection may be applied to investigate complex structural settings through observation of reflected seismic velocities, refracted, and direct waves.
High Definition Crosshole Tomography Cross hole methodology is based fundamentally on propagating elastic waves throughout the geological units and structures within the bedrock. The main technique comprises in generation of elastic waves on the ground surface or at certain depths in a well / shaft, and measuring the time it takes the energy in propagating from the source of origin to the detector-geophones distributed at a certain distances / depths along a well / shaft. By determining the traveling times it is possible to calculate the speed of compression and of cut / slash. Counting both velocities it is possible, additionally, to estimate the elastic modulus of the bedrock under observation.
Downhole Method The downhole method consists in generating of compression and shear of seismic waves on the surface in order to log the seismic energy captured by the geophones located on a single well, uniformly separated at a certain depths. The seismic energy is generated on the surface by knocking a wood board with a claw-hammer; the wood board is located near the well and close to the ground. To obtain seismic waves of compression, the wood board/plank is knocked vertically while the seismic waves of shear are knocked horizontally in opposite directions. That way the register shows different polarities, facilitating the detection of the S wave in the seismograph. By knowing the geometry of the original geophone and the travel times of the seismic waves, it is possible to calculate the velocities of the elastic waves at different depths.