Assessment & Evaluation Techniques Flashcards
7 cards from real CES practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Assessment & Evaluation Techniques flashcards as text
Which factor is evaluated when performing a drop weight impact sensitivity test on a primary explosive?
Answer: The minimum energy input required to cause ignition
The drop weight test determines the minimum impact energy (height × weight of drop hammer) that causes ignition, quantifying the explosive's mechanical sensitivity.
During post-blast environmental assessment, the primary contaminant of concern from detonation of ANFO is:
Answer: Ammonium nitrate residue and nitrogen oxides
Incomplete or unbalanced ANFO detonation leaves ammonium nitrate residue and produces nitrogen oxides (NOx), both of which are assessed for environmental and health impact.
The 'powder factor' metric used in blast evaluation expresses which relationship?
Answer: Pounds of explosive used per ton (or cubic yard) of material broken
Powder factor is the ratio of explosive weight to the volume or mass of rock broken, used to evaluate blasting efficiency and compare designs.
When evaluating a blasting contractor's shot record, which entry is MOST critical for post-blast vibration compliance review?
Answer: Maximum instantaneous charge (MIC) per delay interval
The MIC per delay interval determines the ground vibration level via the scaled distance formula; it is the governing variable for regulatory compliance, not total shot weight.
A CES professional uses the 'time-domain' seismograph record to evaluate blasting. What does the frequency content of the waveform indicate?
Answer: The potential for resonant structural response in nearby buildings
Low-frequency vibration waves are more likely to match the natural resonant frequency of structures, increasing damage risk; evaluating frequency content assesses this risk.
Which standard governs the evaluation and classification of explosive materials for DOT hazardous materials transport in the United States?
Answer: 49 CFR Part 173 (DOT Hazardous Materials Regulations)
49 CFR Part 173 establishes the DOT criteria and tests used to classify explosives into divisions (1.1 through 1.6) for transportation safety evaluation.
When evaluating blasthole drilling patterns, 'burden' is defined as:
Answer: The distance from the front row of holes to the free face
Burden is the perpendicular distance from a blasthole to the nearest free face, and is the most critical geometric parameter governing blast performance and fragmentation.