Week 11: Engineering surveying Flashcards
(44 cards)
1
Q
Four terms of engineering surveying as an umbrella term
A
- Setting out
- Construction surveying
- Monitoring surveying
- Surveyor
2
Q
Setting out component
A
- Essential part of construction
- Position (2D) plus height (1D)
3
Q
Construction surveying component
A
- Control surveys to establish H and V control points
- Mark out lines, points
- Ground profiles, grade
4
Q
Monitoring surveying components
A
High precision deformation - e.g dam monitoring
5
Q
Surveyor components
A
- AKA construction surveyor
- AKA site engineer
6
Q
The construction surveyor is often involved with these varying construction phases
A
- Control and layout
- excavation
- Services
- Concrete forming
- Placing and finishing
- Steel erection - this must work
- Project documentation
- As-built surveys
- Quantity (volume) determination
- Invoicing and charge-out times
And much more
7
Q
Characteristics of a good site surveyor
A
- Honest
- Responsible and reliable
- Commitment to quality
- Must not be afraid to ask questions
- Able to learn new things
- Must be a problem solver
- Be prepared for the unexpected
- Be organised
- A supervisor - can lead multiple field crews
- Good communication skills - oral and written
- Be an initiator - thinking and plan ahead
- Know and understand all manners of survey equipment, measurement, theory and associated errors
8
Q
Primary aims of surveying tasks
A
- Set out positions, 2D and/or 3D
- horizontal setout - N, E
- vertical setout - H
- 3D setout - TS / GNSS - Quick and efficient setout done with:
- minimum time and cost
-varying specified accuracies with reliability
9
Q
Characteristics of the survey site environment
A
- Noisy, dusty, outside, little/no shelter from wind, sun, rain
- Lots of time pressure
- a lot of possible errors and $$ to remedy - Terminology (different terms)
- Health and safety
- Many different types of workers
- whos doing what and who to report to - Find your errors before anyone else does
- need time and ability to do your checks
10
Q
Three essential job records
A
- Field notes
- Daily diary
- Job file
11
Q
Components of field notes
A
- Setting out info - setups, points set out
- Dates, instruments
- Regular claibration info
- Show checks (important)
12
Q
Components of daily diary
A
- Talks with subcontractors and decisions made
- Any equipment changes
- Health and safety issues
13
Q
Components of job file
A
- Field notes copies
- Calculation sheets
- Requests to supervisor/foreperson for changes or clarification and their replies
14
Q
Definition of setting out
A
- The process of transferring marks shown on a plan onto the ground - i.e you aren’t fixing a position, but placing a mark in a fixed position
- Think of it as the opposite of typical surveying
15
Q
Setting out learnings
A
- How things are built
- Ability to work with a variety of people
- laborers, contractors, architects, engineers, developers - Challenging, can be very satisfying, an important skill base to acquire
- Better surveyor, manager and professional
- Reputation on the line every day - it is developed over time
16
Q
Six realities of setting out
A
- Time pressure
- Adverse conditions - dust, noise, space, wet, etc
- Very responsible - errors cause substantial costs nad loss of your reputation
- Read the plans correctly - check/go over the plans first
- Integral part of building team - link between designers and contractors
- Plans and data not absolutely correct nor final
- communication with the designers essential if data is inconsistent, doesn’t fit the site, or any uncertainty exists
17
Q
How is good communication with supervisor/foreperson essential
A
- Busy people, but you need to communicate with them, you are an important part of the site
- Meaning of marks must be understood
- Ask that certain control marks not be destroyed
- Talk to them before and after set out
- Show them what you have done
18
Q
Accuracy requirements for roads, houses and large factory, high rise buildings, bridges
A
Roads - small to large(ish) inaccuracies depending upon the work and end result (but consider machine control - later)
Houses - small inaccuracies may be tolerated
Large structures - typically prefabricated design, little tolerance for inaccuracy
19
Q
Three general procedures and techniques for nearly every surveying situation
A
- Both H and V are often required
- often separately at different times - Some setting out processes once, some use iteration: e.g batter staking
- Always produce a good, well laid out fieldnote drawing of what you have set out - must be easily understood by all
- provide a copy to contractor
20
Q
Six specific principles of general surveying
A
- Work from accurate, well sited, well monumented, well identifiable control
- Work to at least 50% of control accuracy you are using (whole to part)
- Use relative accuracy where required rather than absolute - know the difference
- building corners
- kerb lines - Check all setouts (H and V) independently
- RO, level runs and RLs, GNSS, all hanging lines - Keep in touch with the site regularyl checking on their progress (and your future work)
- Keep the fieldnotes and as-built up-to-date, especially underground services
21
Q
GSP means
A
Good survey practice
22
Q
GSP - Adjustment and calibration of instruments
A
Regularly monitored and recorded
23
Q
GSP - Instrument set up
A
Centring and levelling - particularly important on steep sights
24
Q
GSP - Good fieldnotes
A
Book all relevant details (when, who, instrument settings, prisms, meteorological conditions, marks used)
25
GSP - Long lines to ____, short lines to ____
Long lines to orient, short lines to place
26
GSP - Point ID and stability
Use at least two orienting rays, and/or check distances
27
GSP - Instrument stability
Use frequent observations to reference object, watch the plate bubble regularly
28
GSP - Confirm (prove) orientation before ending set up
Last thing you always do
29
GSP - Checks
Independent and not repetitive for directions, distances, heights (both Benchmark and change in height)
30
GSP - work form the
Whole to the part
31
GSP - Take ____ measurements
Redundant
32
Four benefits of construction surveying
1. Learn various construction techniques
- different types of equipment
- different building methods, concrete, etc
2. Learn good (and many) surveying methods and different procedures
3. Great satisfaction - something built and knowing you had an important hand in it
4. Meet variety of other workers with other cultures, different values and beliefs - good mates and nice money too.
33
5 pieces of set out surveying equipment
1. Dumpy, level / spirit level / digital level
- All HPC overseas, never rise and fall method
- HPC used sometimes in NZ
2. Laser levels
3. Total station
- Used for set out
- free station
- reference line (= offset line)
- tie distance (= MLM)
- reflectorless TS - nice to have
4. GNSS (RTK)
5. Vertical plummet - spcialized equipment (optical, laser)
34
Four surveying essentials
1. Calibration of equipment very important
2. Calculations important
3. Control
4. Computing
35
Nine examples of earthworks
1. Ground clearance extents/limits
2. Initial and ongoing topo's for quantity calculations
3. Excavations
4. Batter stakes
5. Alignments, levels, crossfalls
6. Drains
7. Base course, paving
8. Asphalt
9. Concrete pads, kerbs, etc
36
Five set out basic guidlines
1. Some aspects require lower accuracy
- Fast setout and wide areas
- Clearing limits
- Batter stakes
2. Common survey techniques, but different equipment
- 90 degree prism, Abney, metal bands, compass, cloth tape, etc
- Whatever suits the job (accuracy and time) requirements
3. GNSS ideal on many open construction sites
- Base station setup
- Checks essential watch for multi path errors
4. Machine guidance increasingly used - both Robotic TS and GNSS
- concrete paving and excavation
5. Plan ahead - especially on long, big projects
- e.g level BMs required before drainage sumps
37
Roles for surveyers in general jobs
1. In small sites, could be in sole charge, in charge of ordering materials and equipment
2. Understand varying accuracies of whta is being built
3. Understand/ learn varying clients
- talk to contractors / builders / designers / engineers / council
4. Good communication skills required
38
The five functions of total stations
1. Reference lines or offsets
2. MLM
3. REM
4. Resection or free station
5. Coordinates - relative, absolute
39
What to do on a new instrument
1. Perform checks and calibrations first
2. Learn all the built in functions so RTM
40
Reference line usage
1. Everday use - simple and effective method of setout or pickup
2. 2 points establish a line
- preset in TS or fixed in field, check to 3rd point if possible
3. Position of prism
- terms of (0,0) at 1st point on line
- change in height from grade between points
4. AKA, offsets, projection line, 2D or 3D
41
Characteristics of MLM
1. Missing line measurement
2. First point entered
- tie to it or enter coordinates
3. Examples: athletics, very good check between pegs (cadastral or engineering)
- javelin, discus, shot put, watch olympics
42
Characteristics of REM
1. Remote elevation measurement
2. Good for inaccessible positional info - OH wires, building heights, etc
3. Good for height checks and recession planes
43
Characteristics of free station
1. Resection with added distances
2. Two targets theoretical min
3. 3+ targets should be your practicing aim
4. 2D or 3D
5. Use the info on quality
- standard error of position
- shows residuals on all observations
6. Always check your result
- How? - check to a different point
7. Always check out and confirm the info stored in the TS memory
44
The four steps in set out procedures
1. Enter all points in office
- establish regular and uniform numbering system
- coords - are they absolute or relative
2. Set out function
- preset direction
- TS gives +- distance required to set out point
- can also give distance to reach setout point
3. Height of prism
- important where RL required - keep it as low as possible - reduces source of error (plumbing)
4. Communication - radio/learn hand signals
- construction sites can be very noisy
- needed to mark stakes (c/fs) as you go
