Section 2526. Construction Survey
Perform survey for construction projects.
None.
A. Furnish all survey necessary for construction of the project before work begins in the area. Comply with Iowa Code requirements, including monument preservation, under the direct supervision of an Iowa licensed land surveyor. Do not apply the provisions of Article 1105.14 to this work, except to preserve the original stakes set by the Engineer. Refer to Article 1105.15 for requirements when AMG is utilized. If, in the opinion of the Engineer, the Contractor has destroyed or disturbed any of the original survey stakes or benchmarks, the cost of replacing will be charged to the Contractor. Bring design errors discovered to the Engineer's attention for review prior to staking. Construction survey includes qualified personnel, equipment, and supplies required for, but not limited to, the following items:
1. Monument Preservation
Preserve existing monuments as required by Iowa Code.
2. Project Control.
a. Primary Control Monuments.
A primary control monument is a survey point the Contracting Authority establishes prior to project commencement. The point will be established by placing a monument in the ground.
b. Secondary Control Monuments.
A secondary control monument is a survey point the Contractor establishes on grading or other projects specified in the plans, and preserves on all other projects.
1) The Engineer will provide monuments, similar to those the Department uses for GPS control.
2) Place secondary permanent horizontal control monuments, under the Engineer’s direction, at locations likely to survive project construction and at intervals not to exceed 2640 feet. Place the monuments in the ground along the project corridor. Place at higher elevations along the corridor to provide a view of the immediate project topography and to provide for visible clear line of sight to the nearest secondary permanent control monument in either direction. Primary project monuments may be substituted if appropriate.
3) Plant secondary control monuments 1 to 4 inches below existing ground. Drive a metal fence post within 1 foot to mark their location.
4) Carefully determine project coordinates relative to the nearest primary project control monument using project coordinate values the Engineer has provided. Ensure the resulting error radius of the secondary monument does not exceed 0.10 feet ±2 ppm relative to the primary control.
5) Perform an independent traverse check between the secondary control monuments by observing distance and angular measurements or by use of GPS. Provide the Engineer with a diagram indicating horizontal ground distances to nearest 0.01 foot and angles to at least the nearest 10 seconds between each secondary control monument. Ensure inverses between the coordinate pairs as determined in the previous paragraph do not exceed 0.10 feet of the direct measurements.
6) Replace secondary control monuments disturbed during construction activities using procedures outlined above, at no additional cost to the Contracting Authority.
c. Benchmarks.
1) Establish permanent vertical control benchmarks at all bridges and reinforced concrete box culverts within the project. Use an Iowa DOT brass plug on bridge barrier rail or headwall of reinforced concrete box culvert to indicate the benchmark. If the Engineer approves, a sawn “X” on bridge barrier rail or headwall of reinforced concrete box culvert may be used.
2) Transfer all benchmark elevations from construction plan benchmarks to the permanent benchmarks using the three-wire method or by trigonometric leveling. Use temporary benchmarks of reasonable stability to preserve the plan benchmarks.
3) Ensure benchmark level loops do not exceed an error of 0.05 feet times the square root of the loop’s length in miles. Distribute the error equally along the loop on all intermediate traverse/benchmark points.
3. Grading.
a. General.
1) Survey right-of-way line between permanent right-of-way corners at 100 foot intervals, or less if needed, including borrows, temporary easements, and right of entry. Mark these points by placement of a metal pin or wood hub, flat, and lath at the same location as the slope stakes. Clearly mark the flat with the station number, distance from centerline, and elevation (cut or fill) to subgrade.
2) Take
original and final elevations of all borrows. Provide original and final digital terrain model (DTM) in LandXML format, suitable for use by the Engineer to calculate
excavation quantities.
3) Set bridge berm slope stakes to establish all transitions, including the face of the berm. Set finish grade stakes (blue tops) on all roadway shoulder lines and roadway centerlines to project down the face of the bridge berm at the top, face of berm bench, and toe.
4) When Class 12 excavation is an item, provide original and final DTM in LandXML format for use by the Engineer to calculate the excavation quantities.
5) Use a lath to locate, on each side of roadway at the right-of-way line, agricultural drain tile shown in the contract documents. Clearly mark lath to show station location, distance from centerline, tile size and type, and flowline elevation.
b. Areas Constructed Without AMG.
1) Set slope stakes at 100 foot intervals, or less if needed, for embankment and excavation work including roadway, channel changes, and borrow areas. Interpolations may be necessary to match cross-sections. Set stakes at toe of foreslope or top of backslope, or both. Mark slope stakes with a flat and lath. Clearly mark flat with station location, distance, slope, and cut or fill information.
2) Set grade check stakes at 100 foot intervals for bottoms of subgrade treatments. Set stakes on centerline for two-lane roads and in median for four-lane roads. Mark grade check stakes with a lath. Clearly mark lath with station location and cut or fill information.
3) Set finish grade stakes (blue tops) at 100 foot intervals, or less if needed. Set blue tops at each shoulder line and each point where there is a change in cross slope. Mark blue tops with a wood hub and stake chaser or similar type tassel.
c. Areas Constructed with AMG.
1) Establish elevation of secondary control points using differential leveling from project benchmarks, forming closed loops. Provide a copy of new control point information to Engineer prior to construction work. Contractor is responsible for errors resulting from their efforts. Correct deficiencies to the satisfaction of the Engineer at no additional cost to Contracting Authority.
2) Set hubs at top of finished subgrade at hinge points on cross section at 1000 foot intervals on mainline and at least two cross sections on side roads and ramps. Establish these hubs, using means other than the machine guidance surface (such as plan typicals and cross sections, for use by Engineer to check accuracy of construction.
3) Provide grade stakes at critical transition points such as, but not limited to, PC’s, PT’s, super elevation points, and other critical points required for construction of drainage and roadway structures.
4. Bridges.
a. Mark locations and elevations with metal pin or tack in a wood hub, flat, and lath. Clearly mark flat with the pier/abutment station location, design number, and offset distance from centerline of the approach roadway.
b. Establish a minimum of three temporary benchmarks.
c. Mark location of test pile with a wood hub.
d. Perform an independent check of the above stakes. Independent check shall be performed by a second survey crew using their own calculations and equipment entries for staking bridge. Results and staking layout shall be sent to the Engineer prior to starting structure construction.
e. Submit elevations of all completed substructure beam seats to the Engineer for review prior to installation of bearings and superstructure elements.
f. Take elevations of beams as erected. Develop proposed final deck grades for review by the Engineer on an Excel spreadsheet format. Provide proposed final deck grades to the Engineer for determination of required deck grade adjustments and approval of final deck grades for deck construction. Locations for determining beam elevations are to be according to the plans.
g. Provide the Engineer with a copy of the staking diagram prior to commencing work.
h. For bridges on Primary and Interstate routes, submit required information from Articles 2526.03, A, 4, e and f to the Engineer on the provided bridge e-File spreadsheet.
5. Reinforced Concrete Box Culverts.
a. Mark locations and elevations with metal pin or tack in a wood hub, flat, and lath. Clearly mark the flat with the station location, design number, cut/fill elevation, and offset distance from the centerline of the culvert and back of parapet.
b. Perform an independent check of the above stakes.
c. Provide the Engineer with a copy of the staking diagram prior to commencing work.
d. Report to the Engineer questionable flow lines and alignments that do not match existing drainage.
6. Pipe Culverts.
a. Mark locations and elevations with metal pin or a wood hub, flat, and lath. Clearly mark the flat with the station location, cut/fill elevation, and offset distance to both ends or centerline of pipe.
b. Report to the Engineer questionable flow lines and alignments that do not match existing drainage.
7. Sanitary and Storm Sewers.
Mark locations and elevations with metal pin or tack in a wood hub, flat, and lath. Clearly mark the flat with the station location, pipe number, cut/fill elevation, and offset distance to centerline of pipe.
8. Water Mains.
Mark locations and elevations with metal pin or tack in a wood hub, flat, and lath. Clearly mark the flat with the station location, pipe number, cut/fill elevation, and offset distance to centerline of pipe.
9. Intakes and Utility Accesses.
Mark locations and elevations with metal pin or tack in a wood hub, flat, and lath. Clearly mark the flat with the station location, intake or utility access number, cut/fill elevation (including bottom of well and form grade), and offset distance to the Station Location.
10. Pavements (PCC & HMA).
a. General.
1) Obtain elevations of adjacent pavement and bridges at centerline, edge of pavement, and other locations necessary to characterize existing profile and cross slope. Obtain elevations at maximum 10 foot intervals for a minimum of 100 feet. Adjust design profile grade and cross slope to provide a smooth transition, free of bumps and dips, from the new pavement to the existing pavement or bridge. Notify the Engineer when a smooth profile cannot be provided. Submit final elevations to the Engineer before paving begins.
2) For PCC and HMA pavements, when a new profile grade is not included in the contract documents:
a) Obtain elevations of the existing pavement and bridges at 100 foot intervals on straight and level sections and 50 foot intervals on horizontal and vertical curves.
b) Using these elevations, design a profile grade and cross slopes to provide a smooth transition, free of bumps and dips, from the new pavement to the existing pavement or bridge. Design a smooth profile grade line to provide the required pavement or shoulder thickness as detailed in the contract documents. Notify the Engineer when a smooth profile cannot be provided. Submit final elevations to the Engineer before paving begins.
3) For PCC overlays, when a new profile grade is not included in the contract documents:
a) Obtain elevations of existing pavement at centerline and both pavement edges for bonded overlays and projects including mainline stress relief course and/or pavement scarification.
b) Obtain elevations of existing pavement at centerline, quarter points, and both pavement edges for unbonded overlays and whitetopping projects when a stress relief course and/or pavement scarification are not included.
c) Obtain elevations at maximum 50 foot intervals on straight and level sections and at maximum 25 foot intervals on horizontal and vertical curves.
d) Using these elevations, design a profile grade and cross slopes to provide a smooth transition, free of bumps and dips, from the new pavement to the existing pavement or bridge. Design a smooth profile grade line to provide the required pavement or shoulder thickness as detailed in the contract documents. Notify the Engineer when a smooth profile cannot be provided. Submit final elevations to the Engineer before paving begins.
b. Areas Constructed Without AMG.
Mark locations and elevations with metal pin or tack in wood hub (only tack one side), flat, and lath. Mark elevations on both sides of pavement at 50 foot intervals on straight and level sections and 25 foot intervals on horizontal and vertical curves. Clearly mark flat with station location, cut or fill information, and offset distance to edge of pavement. Include pavement cross slope information in superelevated curves.
c. Areas Constructed With AMG.
1) When total stations are used for the AMG paving system, set additional control points at maximum 500 foot intervals, 250 foot staggered, on each side of pavement. Control points will be set using a suitable pin or stake, at least 14 inches long, with a flush identifiable location, such as a cap, divot, or tack. Ensure local point to point tolerance of 0.005 foot for elevation and 0.02 foot for position. Furnish x,y,z coordinates rounded to nearest 0.005 foot. Mark each control point with lath indicating point number and station. Where feasible, recess pin below grade to protect from equipment or weather.
2) Mark with lath at A, B, C, and D points along superelevated curve transitions and at station equation locations. Additional paving hubs will not be required for mainline pavement.
11. Structural Walls.
a. Survey requirements for structural walls includes the following work types:
1) Mechanically Stabilized Earth (MSE) Walls.
2) Cast in Place (CIP) Retaining Walls.
3) Soil Nail Walls.
4) Tie Back Walls.
5) Noise Walls.
6) Modular Block Retaining Walls.
7) Segmental Retaining Walls.
b. Mark locations and elevations with a metal pin or a wood hub, flat, and lath. Clearly mark the flat with the station location, cut/fill elevation, and offset distance to face of wall.
B. Ensure monument preservation work is completed by a Professional Land Surveyor licensed in the State of Iowa in responsible charge, according to the provisions of Iowa Code 542B. Ensure all other survey work is completed by a Professional Engineer licensed in the State of Iowa in responsible charge or a Professional Land Surveyor licensed in the State of Iowa in responsible charge, according to the provisions of Iowa Code 542B. Submit a resume to the Engineer identifying the field survey personnel and their capabilities to perform the intended requirements.
C. Obtain the Engineer’s approval for the method of determining alignments and elevations and the method of preserving control points. This approval does not act to relieve the Contractor of the responsibility for the correctness of the survey work. Do not use plan cross-sections for vertical or horizontal control.
D. Check tie-ins with existing roadways for correctness of alignment prior to construction staking.
E. Establish benchmarks in the adjacent area before installing settlement plates in accordance with Article 2526.03, A, 2, c. Locate and determine elevations of settlement plates daily during construction and weekly during delays and following the completion of embankment construction, unless approved otherwise by the Engineer. Submit elevations to the Engineer on Settlement Plate Data Form (available at the Bureau of Construction and Materials website).
F. All survey work documentation becomes the property of the Contracting Authority. Assemble required documentation into a single electronic package upon completion of the project and furnish to the Engineer. The work of this specification will be considered when complete the following documentation is furnished to and accepted by the Engineer:
1. ASCII comma delineated file of the coordinates formatted as (Point Number, Northing, Easting, Elevation, Point Description, Feature). Identify coordinate system used.
2. Monument preservation certificates.
3. Secondary control monument coordinates including traverse check.
4. Reference monument drawings.
5. Benchmark coordinates.
6. Required DTMs.
7. Bridge and box culvert staking diagrams.
8. Final profile grades.
G. For the purpose of subcontracting, this item will be considered a specialty item.
2526.04 method of measurement.
None. Lump sum item.
A. Payment for Construction Survey will be paid for at the lump sum contract price.
B. Payment is full compensation for the survey work required for the project as let, including any interpolations that may be necessary between cross-section and field staking.
C. Payment for revisions after the letting will be paid for according to Article 1109.03, B.
D. Verifying form work slopes according to Article 2511.03, B, 1, b, shall be incidental to Construction Survey and will not be paid for separately.