CHAPTER 11: SURVEYING

CONSTRUCTION SURVEYINGDecember 20041105 PRESERVATION OF MONUMENTS AND MARKERS1105-1 GeneralHorizontal and vertical survey controls have been placed at numerous locations throughout the State byseveral Federal agencies. These controls are survey monuments in the form of a concrete monument or aniron pipe with a brass cap. These agencies are the Bureau of Reclamation, Army Map Services, Corps ofEngineers, Forest Service, U.S. General Land Office, Geological Survey, and the Coast and Geodetic Survey;markers of the last three being those most frequently encountered federal markers. There are also surveymarkers set by state, county, city and other local jurisdictions and by utility companies and professional landsurveyors in the private sector. These could be brass caps, iron pipes, steel bars, rebar or just a railroad spikeor large nail.Every effort must be made to recover, protect, and preserve all such monuments, whenever and whereverfound. Federal and State laws provide penalties for the negligent disturbance of all such markers andmonuments. As provided in ARS 33-103 such penalties may also include the cost of surveying to reestablishthe monument or marker and as a result can become very expensive.Location crews, as a part of their preliminary engineering activity, will have located and made ties to allmonuments which they were able to locate in the vicinity of the proposed work. In the case of U.S. GeologicalSurvey or U.S. Coast and Geodetic Survey monuments, the Chief Location Engineer will have madearrangements for their relocation. This relocation will be accomplished by the Federal agency involved and/orPhotogrammetry and Mapping Services prior to the beginning of any construction activities. These crewsmake diligent efforts to locate all in-place monuments but occasionally one may be overlooked. Refer tosubsections 1105-2 and 1105-3 of this Manual in the event that construction crews locate a monument withinthe highway right-of-way or in an area where construction activities may disturb the monument and it has notbeen previously referenced.1105-2 Monuments, Except U.S.G.S. or U.S. Coast & Geodetic SurveyIf the marker is outside the proposed roadway prism, reference and erect suitable protective devices and flagsto insure against disturbance during construction activities. Should it be disturbed, reset in original positionupon completion of project.If it is outside the proposed paved area but within the roadway prism, establish witness corners which willenable relocation of the marker position at any future time. These points shall be iron pins approximately 18inches (0.5 meters) in length, imbedded in concrete. By use of an instrument, set up over the original marker,locate two witness corners on a straight line passing through the original marker. Locate the other two cornerssimilarly on another straight line turned 90 degrees off the first line. Three points shall be set at a locationwhere they will not be disturbed during construction activities. An accurate measurement from the monumentto each witness corner must be made and the distance to each recorded as a permanent project record. Senda complete diagram of the referenced monument, in duplicate, to ADOT Location Division, Phoenix. Themonument and its references shall be tied to the survey centerline stationing of the roadway.If the original monument is within the proposed paved area, it shall be preserved with a Standard Drawing C21.10 Survey Monument and Cover. If the original corner is one established by the U.S. Land Office, thefollowing procedure shall be used: If a stone, encase in concrete, leaving the top exposed, drilling a small holein the stone to mark the true point. If an iron pipe with a brass cap, imbed a portion of the pipe in concrete,letting the original brass cap substitute for the one indicated in Standard Drawing C-21.10. The brass cap shallbe oriented to read from south to north.Construction Manual1105 - 1

CONSTRUCTION SURVEYINGDecember 20041105-3 Monuments, U.S. Geological Survey and U.S. Coast & Geodetic SurveyIn the event such a monument has been overlooked every effort must be made to protect it in its originallocation. Immediate notice of location of the monument must be sent to the ADOT Chief Location Engineer,Phoenix, giving a detailed description of the marker. Enclose an impression of the marker obtained by holdinga sheet of paper tightly over the face of the disk and running a soft lead pencil across the area until the imprintis transferred. The Chief Location Engineer will make prompt reply as to the action which must be taken.Construction Manual1105 - 2

CONSTRUCTION SURVEYINGDecember 20041106 CHECK LEVELS AND BENCH MARKSCheck levels must be run to verify the elevations of the bench marks shown on the plans. Check levels shallbegin at the nearest original bench mark just outside the beginning station of the project. Bear in mind that allbench marks are turning points, and it is important that the level person turn through each bench as they arebeing checked. It is equally important that the rod person is provided with a peg book to check with the levelperson throughout the procedure of the work.At the time check levels are being run, establish all necessary construction bench marks. See Exhibit 1107-2for typical example of check levels. The bench marks, set on the location survey, establish the vertical controlof the construction projects.The plans show all location bench marks, but they are too far apart and not established at strategic places forconstruction work; therefore, the following are a few established practices that can be performed at the timecheck levels are run that will expedite the staking of a project:1. Establish a bench mark at each end of a large structure; one bench mark at the high ground elevationand one at the low ground elevation of the structure. One bench is sufficient at a small structure.2. Establish bench marks at frequent intervals and convenient locations for checking during crosssectioning and setting of blue tops. As a general rule, a maximum of 500 feet (150 meters) betweenbench marks should be observed.3. In rough terrain, establish bench marks at points of change from cut to fill and vice-versa or at highpoint of fill.4. Establish new guard stakes at all old bench marks and all newly established bench marks. The backface of the guard stake will be marked with the abbreviation "B.M." and the B.M. number. The insideface will bear the actual elevation of the bench mark. The guard shall be driven over the bench markat a slant with the inside face of the guard facing the iron pipe.5. In placing new bench marks, a sound, firm ground location should be sought and a 5/8 in. X 18 in. or24in. (1.6 cm X 0.5 m or 0.6 m ) iron pin driven into the ground allowing approximately 2 inches (5centimeters) to protrude. See Exhibit 1107-3 for marking of B.M. stakes.Construction Manual1106 - 1

CONSTRUCTION SURVEYINGJanuary 20051107 CONSTRUCTION STAKESThroughout the work, the Surveyor should see that survey stakes are always provided far enough ahead toenable the Contractor to plan his work. The location and message transmitted by these stakes shall berecorded so that the stakes may be easily replaced if destroyed.Use a beginner's drawing pencil to mark all stakes. The pencil should be blunt enough that sufficient pressurecan be applied to impress the markings slightly into the wood. All writing on stakes shall be large enough foreasy reading. Stakes shall be driven firmly into the ground.Exhibit 1107-1. References of Control PointsConstruction Manual1107 - 1

CONSTRUCTION SURVEYINGJanuary 2005Exhibit 1107-2. Check Level BookConstruction Manual1107 - 2

CONSTRUCTION SURVEYINGJanuary 2005Exhibit 1107-3. Bench Mark StakesConstruction Manual1107 - 3

CONSTRUCTION SURVEYINGJanuary 20051108 STAKING STRUCTURES1108-1 GeneralConsiderable preliminary paper layout work and computing can be performed in the construction field officebefore ground layout of structures is started. The extent of the preliminary work will depend on the complexityof the structure.Generally speaking, there are three distinct types of structures which will require staking. They are pipeculverts, concrete box culverts, and large bridge type structures. The following subsections are guides whichmay be used in the layout of these structures.1108-2 Pipe CulvertsA study of the normal flow of the drainage should be made before staking is done. It is always possible thatthe normal drainage pattern may have changed between the time of design and construction which mayrequire a change in the location of pipe culverts.If possible, all pipe should be staked with length and alignment verified prior to the Contractor placing his orderfor the pipe.In staking pipe culverts, in order to attain proper placement of the pipe, it is often necessary that the roadwaysections adjacent to the pipe be slope staked. If this practice is employed, no error should occur in length orproper placement of the pipe. In the event that the slope staking cannot be done, the distance that the pipeshould extend each side of centerline may be determined by plotting the pipe and the road, the cross-sectionat the structure location, and scaling the distance from centerline to each end of the pipe.The centerline station through which the centerline of the culvert pipe will pass is located and marked with astake or guinea. Set the instrument on this point, take a sight tangent to the centerline and turn the requiredangle for the centerline of the pipe. Along the line thus established, measure off the culvert lengths right andleft of centerline and place a hub at each end of the pipe location.After the two ends of the pipe are established, references to these points are set. If there is an inlet or outletchannel, or both, the pipe should be referenced to the sides. If no channel excavation is necessary, it ispossible to reference straight out from the ends. With an elevation from the nearest bench mark, determinethe elevation of the top of each reference hub, and compute the cut or fill from it to the flow line point at eachend of the pipe. Behind each reference hub, set a guard stake on which has been marked the hub's identity,the offset distance, and amount of cut or fill from the reference hub to the flow line point.Take necessary notes and make structural excavation diagrams in order to compute structural excavation. Ifdrainage excavation is required, the inlet and outlet channels should be slope staked at the time the pipe isstaked. (See Exhibit 1108-2-1.)When elevations are provided to the Contractor for setting of pipe, or for any points on any structure, the levelnotes should record the bench mark elevation. The level circuit notes should always show closure on thesame, or another, B.M. The purpose obviously is to reduce the chance of error.In addition to pipe culverts, long horizontal pipe runs will also be staked for construction. These runs may gofrom manhole to manhole or to catch basins. These grades must be checked using manhole or catch basininverts as the control and figuring the grade in between the structures. Pipe should be staked on anConstruction Manual1108 - 1

CONSTRUCTION SURVEYINGJanuary 2005appropriate offset line at no greater than 50 foot (15 meter) intervals. Where flow is critical, such as in sanitarysewer installations, then pipe should be staked with a cut to flow line of pipe every 25 feet (7.5 meters). Aguard lath should be provided indicating cut to flow line, offset to the centerline of the pipe and station.1108-3 Concrete Boxes and Bridge CulvertsThe size and type of box culvert to be staked will be designated on the plans. Particular attention must begiven to the type of wing walls called for on the plans.Since concrete culvert stakes are used for more precise measurements than in the case with pipe culverts, thelayout points are marked with hubs and tacks. Wingwalls are staked according to the standard drawing orspecial details designated in the plans.Basically, the same method is used in staking box culverts as for pipe culverts. Additionally, stakes must beset to locate the intersection of the barrel and the back face of the wing and the end of the wing. Referencecontrol lines for each wing wall and wing to barrel intersection point should be set using two tacked hubsappropriate distances outside of the construction area from the end of the wing, 15 to 25 feet (4.5 to 7.5meters) are usually satisfactory. All tacked hubs shall be referenced as to the fill or cut to the bottom of thefooting elevation.Guard stakes shall be well marked. Box culverts should be checked for necessary revisions to meet drainagerequirements. (See Exhibit 1108-3-1.)1108-4 Large Structures (Bridges)Prior to commencing the actual field layout of a major structure, considerable preliminary work is necessary.The first step should be a complete check of all distances and elevations shown on the plans. Likewise, allsurvey instruments should be checked and any necessary adjustments made.It is always sound engineering practice to be certain that elevations given for bottom of footings and otherelevations shown on the construction plans are computed correctly from finished grade down or from bottom offooting to finished grade.After determining that the plans are correct, it is good practice to make a rough paper layout of how you intendto stake and reference the structure at the construction site. Exhibit 1108-4-1 will illustrate one acceptablemethod of laying out and referencing a structure of this type. Remember that all centerlines and bearing linesmust be staked and referenced so that a minimum of time and effort are necessary in replacing any disturbedcontrol lines as construction progresses.After staking of the structure has been completed, a thorough check of all measurements, angles, andelevations should be made to make certain that no errors exist. This checking should, if possible, be done by adifferent party than the one which performed the original staking. Checking should be by a different method ifpractical to do so. An example of using two methods of staking the centerline of piers, bents, or abutments is:1. Stake the original layout using the dimensions between the substructure units as shown on the bridgesheets of the plans.2. Compute the station distances for the centerline of each substructure unit and locate them bystationing. Always make certain that the staking is correct, never take anything for granted whenstaking a bridge.Construction Manual1108 - 2

CONSTRUCTION SURVEYINGJanuary 2005If the least doubt arises, consult the plans and double check. Verify the staking carefully and becertain that all distances, angles and elevations are correct, then go over the structure layout in detailwith the Contractor to make sure he or she knows the purpose and location of each stake. SufficientRP's shall be provided for such items as caissons so that drilling and cage placement may bechecked throughout the installation process.1108-5 Structures On CurvesExtreme care must be exercised in staking structures on curves. A very thorough study of the plans should bemade before staking begins. In all cases, a layout of the structure should be made on paper. In some cases, itis also advisable to make an actual layout of the structure on level ground where measurements, staking, andchecking of chords, angles, etc., are facilitated.After being completely satisfied as to the controls needed and all measurements, angles, and elevations havebeen checked, and double checked, you are better able to proceed with an accurate layout of the structure.Layout staking of bridge structures must be checked by another method such as with rectangular coordinateswhich can indicate whether all the angles and distances close and provide diagonal dimensions.Construction Manual1108 - 3

CONSTRUCTION SURVEYINGJanuary 2005Directions:1.Establish station location at point where survey centerline and centerline of pipe intersect (point 1). Mark this point with stake and tack or nail.2.Occupy point 1 with an instrument and backsight or foresight to control point on centerline. Clamp vernier and turn angle that pipe line formswith centerline of roadway. Chain Distances right and left of centerline as per plans or modified pipe lengths and set stake and tack at bothends of pipe (points 2 and 3). If pipe has no channel or headwall, references may be set to ends of pipe on this same line.3.If pipe has channel and/or headwall the following reference procedure should be used: Occupy point 2 and sight point 3. Clamp vernier andturn 90 degrees. Set reference points with hub and tack at 10 feet (3 meters) and 25 feet (7.5 meters). After these references are set, re-sightpoint 3, turn 90 degrees to the opposite side and set similar references.4.Move the instrument to point 3 and repeat procedure using point 2 as a backsight.Exhibit 1108-2-1. C.M.P. OR Pipe Culvert Staking LayoutConstruction Manual1108 - 4

CONSTRUCTION SURVEYINGJanuary 2005Directions1. Locate by stationing the point at which barrel line intersects with roadway centerline (1). Mark this point with 1in. X 2 in. X 14 in. (2.5 cm X 5cm X 36 cm) stake and tack.2. From this point, establish other barrel line intersection (2) and set stake and tack.3. Set transit over point (1), sight back to centerline control point and turn plans angle. Chain off required distance and establish points (3) and(5) with stake and tack.4. Follow same procedure occupying point (2) and establishing points (4) and (6).5. Having established points (3), (4), (5), and (6), the transit is moved to point (3) or (4) and the unoccupied point (3) or (4) is sighted upon andthe vernier locked. Indicated references are then set to points (3) and (4). This procedure will be repeated with points (5) and (6).6. Assume above occupancy was at point (3). After setting references required, the wing angle as indicated on the plans shall be turned andthe end of the wing will be established with stake and tack and referenced with hub and tack. This procedure will be repeated occupyingpoints (4), (5), and (6).7. A quick measurement check of the layout should be made to make certain that structure is properly staked.Exhibit 1108-3-1. Concrete Box Culvert La

1150 contractor construction surveying 1150-1 general instructions 1150-2 study and checking of plans page 1 of 2 . table of contents chapter 11: surveying 1150-3 staking structures 1150-4 slope stakes 1150-5