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Name the maximum thickness of soil layers when compaction is done by hand - NSC Civil Technology Civil Services - Question 4 - 2023 - Paper 1
Question 4
Name the maximum thickness of soil layers when compaction is done by hand. Give a detailed explanation of the compaction process and its constraints. Explain the r... show full transcript
Worked Solution & Example Answer:Name the maximum thickness of soil layers when compaction is done by hand - NSC Civil Technology Civil Services - Question 4 - 2023 - Paper 1
Step 1
Name the maximum thickness of soil layers when compaction is done by hand.
Answer
The maximum thickness of soil layers that can be compacted by hand typically should not exceed 300 mm. This limit ensures that effective compaction is achieved, preventing any voids or weak spots within the layer.
Step 2
Explain how the lid of a concrete ring manhole deeper than 750 mm should be set to ensure airtightness.
Answer
The lid of a concrete ring manhole that is deeper than 750 mm should be set with a rubber gasket or sealant to ensure airtightness. This prevents water ingress and helps maintain the structural integrity of the manhole. It is crucial to check the alignment and overall fit of the lid to ensure a secure seal.
Step 3
Name the length of the engineered bricks that are used in manhole construction.
Answer
The standard length of engineered bricks used in manhole construction is typically 250 mm. These bricks are specifically designed to withstand the compressive forces and loads encountered in manhole applications.
Step 4
Draw a two-dimensional sketch to show how the sides of excavations in loose and water-logged soil should be supported.
Answer
To support the sides of excavations in loose and water-logged soil, shoring methods such as sheet piling or braces can be used. The sketch should show vertical supports at regular intervals and indicate how they connect to the excavation walls, ensuring stability and preventing collapse.
Step 5
Name the tool and accessory that can be used to test if the slope of a drain pipe is correct over a short distance.
Answer
A leveling instrument or a digital level can be used to test the slope of a drain pipe over a short distance. These tools help verify that the slope meets the required specifications for proper drainage functionality.
Step 6
Who must monitor the free end of the rope attached to the safety harness of the worker?
Answer
A competent safety officer or designated safety supervisor must monitor the free end of the rope attached to the safety harness of the worker. This ensures that the worker is safe and that any potential fall risks are mitigated.
Step 7
Explain TWO safety precautionary measures that must be taken before a worker enters a confined space to work.
Answer
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Conduct a thorough risk assessment of the confined space to identify potential hazards such as toxic gases, oxygen deficiency, or physical hazards. Ensure that all safety protocols are in place before entry.
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Provide appropriate personal protective equipment (PPE) such as respirators, helmets, and harnesses to the worker. Ensure that they receive training on how to properly use this equipment.
Step 8
State TWO regulations that must be adhered to when working in elevated places.
Answer
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Workers must be secured by a harness connected to a reliable fall protection system to prevent falls from height.
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Regular inspections of ladders, scaffolding, and other elevated work platforms must be conducted to ensure they are safe for use.
Step 9