Answer questions
1/13/2020
1
Fieldwork Practices-Part 1
CSMT 345
LECTURE 3
1
Fieldwork Practices
• Safety
• Measurement Principles
2
1/13/2020
2
Fieldwork Practices
3
Fieldwork Practices
4
1/13/2020
3
Fieldwork Practices
5
Safety
• Construction industry is a hazardous industry (costing billion of dollars annually)and Safety is often taken for granted – Work related injuries including fatalities occur more often
• Developing a responsible attitude is key – A field engineer is responsible for observing safe practices
amongst craft people on the site • ideally everyone should be fully responsible
– Attitude is everything!
• Good, positive attitude about safety will get others more concerned and is key to avoiding jobsite accidents
6
1/13/2020
4
Personal Protective Equipment (PPE) • Hardhats
– Select hardhats that is adjustable, fit well, and wont interfere with sighting through the instrument scope
• Eye protection (safety glasses with side shields )
• Hand protection (gloves)
• Fall protection
– Safety belts and harnesses at heights over 6’-especially when surveying and marking points on high or sloping areas
• Safety vests
– Field engineers may be surveying hazardous areas (whether on jobsites where heavy equipment is operating or next to highway where cars are moving fast). They should wear highly visible florescent safety vests at all time
– Vests with pockets to carry small surveying tools are preferred 7
Personal Protective Equipment (PPE) cont..
• Ear protection
– Sites are usually noisy; field engineers should have some ear protection at all times (e.g. ear muffs, plugs)
• Foot protection
– Slips, falls, and trips are common site accidents
– Select shoes that are sturdy and protect against compression, slip and puncture.
– Boots should have ample room to avoid foot problems
– Steel toe safety shoes/boot is always preferred
– Note: When your feet hurt, you hurt all over
8
1/13/2020
5
Crew Protective Equipment • Each crew is responsible for warning other workers and
public that they are working on a site and they need various safety equipment – Warning signs
• ‘Survey Crew ahead!’ sign can tell drivers to slow down
– Survey Cones
• Every survey vehicle has them
• Should be highly visible and reflective even in low light. The bigger (28’’ high) the cones, the more visible they are
– Flashers and barricades
• Used in extremely hazardous areas to prevent crew from harm
• Installation of concrete barriers around surveying control points usually provide the required degree of safety in hazardous areas
9
Crew Protective Equipment
10
1/13/2020
6
Crew Protective Equipment
11
Crew Protective Equipment • Dressing for the environment
– Must be concerned with more than physical hazards, e.g., summer heat or winter weather; skin cancer (using sun screen in summer), drinking plenty of water; moisture control in cold weather is key; avoid frost bites (hypothermia)
– Know the weather conditions and plan accordingly
12
1/13/2020
7
Hand tools hazards • Crew should be trained on proper care, operation and
provided with proper safety equipment to work with in surveying
• Common examples; – Machete
• Make sure no one is close to you when working with it
– Chain saws
• Used for heavy clearing
• Wear proper PPE (hardhat, well fitting clothing, safety boots with protected ankles in the event of tool slip…steel toes will prevent injury from falling logs
• Always wear protective gear when using chain saws
• Note:
– remember that the safest cutting tool is the sharp one 13
Natural Hazards • In addition to weather and equipment hazards, surveying in
the field may expose you to many dangers
– Plants (thorns, poisonous types)
– Wild animals (foxes, dogs)
– Snakes (poisonous snakes)
• Most poisonous snakes have triangular shaped heads.
• When beaten, be calm, identify if poisonous or not and seek for anti-venom treatment. Excitement makes the blood (with venom) speed to the heart and maybe dangerous
• Wear knee high boots or leggings for protection
– Insects
• Wasps, bees, spiders, scorpion
• More people die annually from bee stings than snake bites
• Proper PPE is needed, e.g., gloves, long sleeved shirts, etc. 14
1/13/2020
8
Highway hazards
• Consider man-made dangers when surveying on public roads
• It is your responsibility as field engineer to see that workers are in safe working conditions.
• Include signs, barriers, traffic cones, and orange vests (florescent vests to make crews more visible to average drivers)
• You should have a flag person in addition to signs if need be
15
Construction hazards
16
1/13/2020
9
Construction hazards
17
Construction hazards
• High voltage power lines
– Wooden rods are the safest compared to metallic rods near powerlines
– Caution: never touch any powerline with any surveying rod
• Heavy equipment and trenches
– Proper shoring of trenches and cutting at proper angle of repose
– Conducting survey work in trenches must be within operator’s sight or line of view
• Falls
• Noise
• Note: it is the job of field engineer to observe good safety practices on jobsites 18
1/13/2020
10
Measurement Principles
• A field engineer must have knowledge to perform standard surveying measurements on jobsites
• Standard surveying knowledge includes
– Measuring distances, angles, elevations; and understanding mistakes and errors, proper notetaking and care of equipment
• The field engineer must
– Reduce the size of errors in measurement
– Eliminate mistakes
– Understand rules/principles of measurement
19
Measurement Principles
• Total Honesty Needed
– Report what you measure, not what you have calculated that you should measure, or what you think someone wants to hear
– No cover-up of mistakes as they may be discovered eventually and will cost more to correct
– Be a good communicator and listen to foremen/women and craft people
– You should be able to advise everyone of the meaning of information written on stakes or other survey marks so the correct work is done
20
1/13/2020
11
Measurement Principles
• Mistakes vs Errors
– Errors can be managed but mistakes are bad in surveying
Mistakes (blunders):
– occur due to carelessness, lack of understanding of plans, lack of knowledge about measurement techniques or lack of knowledge of measurement equipment
– Their effects are large
• Forgetting that a foot was cut when using a chain saw
• Setting an instrument a few degrees off
– Note: check and recheck your work to avoid mistakes
Errors
- Usually occur
– Can be because of instrument calibrations/imperfection
– Their effects are usually small
– Human error vs instrument errors 21
Measurement Principles
• Accuracy vs Precision – In measurement, you can have accuracy without precision and
vice versa
– All measurements work must be accurate but try to achieve precision depending on the surveying conditions, i.e., we must work on the precision of the equipment and our measurement to achieve the accuracy required in surveying layout
– Example:
• A building construction with accurate plans, built perfectly with everything straight, leveled and plumb. After completion for it to be discovered that it was incorrectly located on the site. In this case, there was good precision and no accuracy
22
1/13/2020
12
Measurement Principles
• Accuracy vs Precision cont..
– Accuracy
• Being able to obtain the true value with the measurements taken, i.e., 10 measurements taken should be close to the true value on average.
• E,g., bull’s eye aimed but shots hit all around with some hitting the target
– Precision
• The closeness of the measurements to each other, i.e., all the measurements will be nearly the same
• This closeness of the measurements does not mean accuracy
• E.g., bull’s eye aimed but all shots are at one place off the eye
– In construction layout, we want both accuracy and precision
• All shots to hit bull’s eye every time we measure (accurately and precise 23