class objectives - university of idaho notes/class...example of profile-leveling field notes....

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CE 211 – SURVEYING ENGINEERING CLASS 09: LEVELING (3)

Ahmed Abdel-Rahim, Ph.D, P.E.

Associate Professor, Civil Engineering

Class Objectives

• Identify benchmark leveling procedures

• Develop field notes for benchmark leveling and computation and adjust benchmark elevations

• Identify profile leveling procedures

• Develop field notes for profile leveling and computation and adjust benchmark elevations.

VERTICAL CONTROL (BENCHMARK) SURVEYS

• Benchmark Leveling and Field Notes

– Field Procedure

– Checking for Mistakes

• Error of Closure and Precise Leveling

– Precise Leveling

– Benchmark Monuments

• Adjusting Benchmark Elevations


FIGURE 5-21. (a) Plan of benchmark leveling.

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FIGURE 5-21. (Continued) (b) Side view of the benchmark leveling run in (a).


FIGURE 5-21. (Continued) (c) Form of field notes used with benchmark leveling.


FIGURE 5-22. (a) Level set up too low. (b) Level set up too high.

Example-1

• A differential leveling loop began and closed on BM Bridge (elevation 814.687 m).

• Readings (in meters) listed in the order taken are 0.548 (BS) on BM Bridge, 1.208 (FS) and 0.843 (BS) on TP1, 1.287 (FS) and 1.482 (BS) on BM X, 0.743 (FS) and 0.944 (BS) on TP2, and 0.571 (FS) on BM Bridge.

• Prepare, check, and adjust the notes.

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Example-1

Example -2

• A leve1ing circuit began on BM Hydrant (elevation 85.35 ft) and closed on BM Rock (elevation 96.17 ft).

• Readings (in feet) given in the order taken are 2.65 (BS) on BM Hydrant, 3.51 (FS) and 7.23 (BS) on TPl, 5.04 (FS) and 11.41 (BS) on BM 1, 8.58 (FS) and 7.65 (BS) on BM 2, 4.23 (FS) and 7.53 (BS) on TP2, and 4.34 (FS) on BM Rock.


Example 2

Example 3

• A differential leveling circuit began on BM Rock (elevation 543.202 m) and closed on BM Manhole (elevation 545.551 m).

• Readings (in meters) listed in the order taken are 1.559 (BS) on BM Rock, 0.987 (FS) and 1.105 (BS) on TPl, 0.842 (FS) and 0.679 (BS) on BM 1, 1.846 (FS) and 0.849 (BS) on BM 2, 1.895 (FS) and 1.436 (BS) on TP2, and 0.704 (FS) on BM Manhole.


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Example 3


Table 5-1. Accuracy Standards for Vertical Control Surveys

Example -4

• A leveling loop with a total length of 900 m had a misclosure of 0.010 m, what order of leveling is represented

Example -4

• A leveling loop with a total length of 900 m had a misclosure of 0.010 m, what order of leveling is represented

• Order of leveling: C= 12mm 0.90 =11.4 𝑚𝑚

• Meets third order

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FIGURE 5-23. A precise level with parallel plate micrometer enables vertical displacement to be measured to 0.1 mm. An accuracy of + or - 0.2 mm in 1 km of leveling (;0.001 ft/ml) can be obtained. (Courtesy of The Lietz Company.)


FIGURE 5-24. Illustration for Example 5-1.


Table 5-2. Adjusting (Closing) a Line of Benchmark Elevations

PROFILE LEVELING

• Profile leveling is one of the most common applications of running levels and vertical distance measurement for the surveyor.

– The results are plotted in the form of a profile, which is a drawing that shows a vertical section or “side view” of the earth’s surface.

– Profiles are required for the design and construction of roads, curbs, sidewalks, storm drainage systems, water supply or sewer pipelines, and many other types of public infrastructure.

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PROFILE LEVELING

• Field Procedure

• Plotting the Profile

• Cross-Section Leveling

PROFILE LEVELING

FIGURE 5-25. Profile leveling; several rod shots are taken from each instrument position.

PROFILE LEVELING

FIGURE 5-26. Example of profile-leveling field notes.

PROFILE LEVELING

FIGURE 5-27. (a) Top view showing the route centerline and the line for cross-section leveling at station 1 + 50. (b) The cross section, showing ground elevations at points left and right of the centerline.

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PROFILE LEVELING

FIGURE 5-28. Cross-section field notes.

Example • Below are rod readings in the order in which they were taken. The elevation of

the starting benchmark is listed at the top of the column. The last reading is taken on the starting benchmark. Put into proper field note form, include arithmetic check. If the B.S. & F.S. distances are 150 feet, what is the order of accuracy? Balance the bench run error

Example • Reduce and plot at a scale of 1”=200’ horizontal and 1”=20’

vertical, the following set of profile notes.

class objectives - university of idaho notes/class...example of profile-leveling field notes....

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