Ground Conditions & Stability Flashcards
6 cards from real CPCS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Ground Conditions & Stability flashcards as text
What is the 'safe standoff distance' from an excavation edge for plant?
Answer: The minimum distance plant must be kept from an excavation edge to prevent edge collapse — determined by soil type, depth, and plant weight
Safe standoff distance is the minimum distance between plant and an excavation edge to prevent collapse. It depends on soil type, excavation depth, and plant weight, and must be calculated by a competent person.
When should the ground conditions assessment be updated during plant operations?
Answer: Whenever conditions change — after rain, after significant plant trafficking, or after excavation work nearby
Ground conditions change with weather, plant trafficking, and nearby excavation works. The assessment must be updated whenever conditions change significantly, not just at the start of a project.
What does the term 'softening' of ground mean in construction plant operations?
Answer: The reduction of ground bearing capacity due to moisture, trafficking, or disturbance
Ground softening is the reduction of bearing capacity caused by moisture absorption, repeated plant trafficking, or excavation-related disturbance. Softened ground cannot support the loads it previously could.
What type of ground is particularly prone to sudden collapse under plant loads?
Answer: Cohesive soils (clays) when wet, filled ground, ground with voids, and ground near excavations
Wet cohesive soils (clays), filled ground, ground containing voids, and ground near excavations are particularly prone to sudden collapse under plant loads, requiring special assessment and precautions.
How should an operator respond if the plant begins to sink into the ground during operation?
Answer: Stop operation immediately, move the plant if it can be done safely, and report to the supervisor
Sinking during operation indicates the ground bearing capacity is being exceeded. The plant must be stopped immediately and moved if possible without worsening the situation. The area must be reassessed before any further use.
What is the significance of a geotechnical report for a site where heavy plant will operate?
Answer: It provides technical data on ground conditions, bearing capacity, and any hazards, enabling safe plant positioning
A geotechnical report provides essential technical data on ground conditions, bearing capacity, underlying geology, and hazards. This information enables competent persons to plan safe plant positioning and load limits.