Civil Engineering Surveying

Roy Frank

Planning A Survey Planning requires a well rounded

understanding of surveying practices Process:

1. Choice of accuracy required (depends on use to be made)

1. Basic Control2. Topographic3. Photogrammetry

Planning A Survey2. Existing Control

1. Search records for existing control in area1. Illinois Geological Survey – Urbana, IL2. National Geodetic Survey – Rolla, MO or Rockville,

Maryland

3. Reconnaissance:1. Search Procedure:

1. Description often dated2. Can use GPS receiver (Lat. And Long)3. Probe, detectors – often problems - brass

Planning A Survey4. Choice of Instruments and Methods

1. Depends on availability, location, existing features, and accuracy

5. Computation and Drafting

Accuracy and Errors Accuracy depends on:

1. Precise instruments2. Precise Methods3. Good Planning

Example: Angle turned with theodolite, pointed with care; readings checked thus good precision. Angle’s of 2-3” expected, real results angle’s 15” = accuracy

Errors 3 Types

1. Blunders 2. Systematic Error3. Accidental Error

Blunder is a mistake, to help eliminate:1. Every value to be recorded must be checked

by some independent field observation

Errors2. Once check indicates that there is no blunder,

field record must never be changed or destroyed

3. An overall check must be applied to every control survey. Make as many overall checks as possible.

Errors Systematic Error – an error that under the same

conditions will always be of same size and sign. Basic Rules to Eliminate:

1. All surveying equipment must be designed and used so that whenever possible systematic errors will be eliminated automatically

2. Systematic error which can not be eliminated must be evaluated and their relationship to conditions that cause them must be determined.

Example: Temperature Corrections

Errors Accidental Errors – (random errors)

represent the limit of precision in the determination of a value

Corrected be laws of probability Compass Rule and Least Squares

Hydrographic Surveys1. Surveys and mapping of bodies of water and

shorelines 2. Rivers and Lakes – Process different

2. Rivers 2. Normal process is to establish 2 parallel lines of control

points on opposite sides3. River Portion: 2 processes

2. EDM similar to radial3. Dual instrument with position by angle and intersection

3. Lakes2. Normal process same as river but generally do not have

current problems

Overall Process:1. Establish control points both horizontal and

vertical2. Preplan where sections are to be taken (this is

basis for control points on shore)3. Cross sections taken4. If EDM, radials taken from control points due to

difficulty in obtaining shots under 300’5. May have to combine cross sections and radial

location to pick up anomalies not covered by cross sections

Gauging Stations Purpose is to install either manually read or

automatic gauges to determine stream, river, lake, or ocean elevations

Process:1. Establish system of BM’s throughout area gauges

will be installed2. Establish elevation mark at site for installation3. After gauges are installed, check elevation of

each

Topographic Surveys 6 Basic Methods1. Radial2. Plus/Offset

2. Plus Offset2. Establish baseline (Often centerline), establish

points at station interval 50’, 100’, 200’3. Tie planimetric data by distance down line plus

distance right or left (looking up stationing)4. Establish elevations on station points then elevation

out a predetermined distance with shots at breaks

Topographic Surveys4. Due additional section to locate features in between

stations5. Equipment: Tape, Level, Rod, Transit, - Right Angle

Prism?2. Grid Method

1. Take cross Section Groups and Combine2. Establish Grid baseline – often property line3. Establish Perpendicular line4. Both Marked at grid interval (25’, 50’)5. Planimetric tied plus/offset in each grid6. Grid laid out by double taping7. Field notes 1 – 2 grids/page

Topographic Surveys3. Photogrammetry

1. Limitations1. Trees – Leaves off – no large growths of coniferous2. Ground Cover – grass, thick weeds and vines, snow3. Clear Sky4. Tall Buildings Due to these Limitations Illinois only has on the

average of 2 weeks flying time

Topographic Surveys Scale – Photo S = (f/H’) Coordinates From Photos XA = (xa/f)(H-ha) YA = (ya/f)(H-ha) Height of an object r = radial dist. to top d = radial dist. to top – radial

dist. to bottom h= d (H’) / r

Topographic Surveys4. GPS: Total Station System

1. Basic of GPS1. Topo with GPS2. Topo: Trimble Total Station (RTK)

2. Limitations:1. Must be able to maintain satellite signal – Trees,

Building2. Signal Reflection (Multipath) – Buildings, Fences,

Roofs3. Debate over elevation (0.15’ +/- my belief)

Topographic Surveys5. Trace Contour

1. Used to identify several contours around an area

6. Plane Table Surveys1. Rarely used2. Method prepares a manuscript map in the field

Mapping and Map Drafting 2 Basic Types of Maps used in

Engineering1. Line Drawing2. Photogrametrically prepared manuscript or

orthophoto map

Mapping and Map Drafting1. Datum in Mapping:

Datum used to correlate measurements, to determine elevations and horizontal positions for points at different locations

Topographic Maps using Symbols Show:1. Spatial configuration of Earths surface

(contours)2. Natural Features (Lakes, Rivers, etc.)3. Physical Changes caused by man

Mapping and Map Drafting2. Planning Maps

Used in planning Engineering work or overall planning at the urban, Regional, or National Levels

3. Plotting Contours: Interpolation:

1. Estimation2. Computation

Mapping and Map Drafting4. Contours

Characteristics of Contours:1. Horizontal distance between contour lines is inversely

proportionate to the slope2. Uniform slopes have contours evenly spaced 3. Along plane surfaces (manmade) contour lines are

straight and parallel4. Contour lines are perpendicular to lines of steepest slope 5. All contours close upon themselves6. Different contours do not merge or cross one another

(except vertical walls, overhangs, cliffs) on map

Mapping and Map Drafting Factors that influence choice of map scale

1. Clarity with which features can be shown2. Cost (larger scale – higher cost) 3. Correlation of Map data with related maps4. Desired size of map sheet5. Physical factors (number and character), nature

of terrain, required contour interval

Mapping and Map Drafting5. Map Classifications

Based on American Society of Civil Engineering, Surveying, and Mapping Division

1. Design Maps: Used to design and construct

6. Information shown on Maps:

Mapping and Map Drafting1. The following should be on a map:

1. Direction of Meridian (North)2. Graphical Scale (Bar in case of reduction)3. Legend or key of symbols4. Title Block (identifiers)5. Contour Interval6. Datum to which both Horizontal and Vertical are

Referenced7. If coordinate base used – what system

Mapping and Map Drafting2. If map is to become public record (subdivision).

It must contain in addition to the above:1. Length of each line2. Direction of each line (bearing or angles)3. Subdivision numbering system (lot and block)4. Location and Kind of monuments5. Names of property owners (on site and adjacent)6. Full description of Boundary7. Certificate of Surveyor that map is correct

Planning and Estimating from Topo Maps1. Purpose of Topo maps2. Profiles3. Grade contour4. Drainage Area

Limits determined by following characteristics:1. Begins and ends at the point in the stream to which it applies2. Passes through every saddle that divides drainage area3. Often follows ridges

5. Reservoir Capacity

Earthwork Computations by Average End AreaPrepare Cross Sections Differentiate between existing & proposed

Planimeter Cross Sections Amount of cut & fill for each cross section Beginning and end stations have 0 value

Compute Volume Conversion Constant: 1.852 = (100/27)/ 2 = {(Sta. Dist.)/ [CF/CY]} / 2

Earthwork by Average End Area EARTHWORK BY AVERAGE END AREA

(EXAMPLE) END AREAS: STATION CUT EMBANKMENT 0+00 0 0 1+00 10 156 2+60 50 795 3+00 197 1526 4+80 5 110 5+00 0 0

SAMPLE END AREASTATION SUM SUM CUT FILL CUT FILL D/100 CUT FILL CUT FILL 0+00 0 0 10 156 1.0 10 156 10 156 1+00 10 156 60 951 1.6 96 1522 106 1678 2+60 50 795 247 2321 0.4 99 929 205 2607 3+00 197 1526 202 1636 1.8 364 2945 569 5552 4+80 5 110 5 110 0.2 1 22 570 5574

CUT: 570 X 1.852 = 1056 Cubic YardsEMBANKMENT: 5574 X 1.852 = 10324 Cubic Yards Compaction Factor = 25%, 10324 CY X 1.25 = 12905 CY Fill

U.S. Rectangular System “IDEAL” Process:1. Area divided by establishment of Principal

Meridians and Baselines2. Area divided into 24 mile square tracts

quadrangle using guide meridians and Standards of Parallel (correction lines)

3. Divide 24 mile² tracts into 16 townships each 6 miles square

4. Divide townships into 36 one mile square sections

U.S. Rectangular System “IDEAL” Process:1. Area divided by establishment of Principal

Meridians and Baselines2. Area divided into 24 mile square tracts

quadrangle using guide meridians and Standards of Parallel (correction lines)

3. Divide 24 mile² tracts into 16 townships each 6 miles square

4. Divide townships into 36 one mile square sections

Easements Easement is a Legal document which allows

someone to do something to and or through your property

Types:1. Access (ingress/egress)2. Construction3. Water rights4. Utility

Easement must Describe1. What it is for (purpose)2. Who between

Must be signed by all who’s name appears on deed

3. Width of easement4. Duration – specified number of years or

perpetual or life5. Description of where located

Based on Rectangular system unless subdivision

Description Method for Waterline Easements A strip 30 feet wide over, under, and across

the _____ side of the _____ ¼ of the _____¼ of Section, ___, T__ __, R__ __of the ___ P.M., __________ County, Illinois said strip lying ______ of and adjacent to the _______ right of way line of the existing public road.

Global Positioning System(GPS) Worldwide system of navigation satellites

by U.S. Department of Defense Started in 1982 Civil GPS Service (CGS)

Views civil users in 3 groups:1. Professional 2. Commercial3. Recreational

Global Positioning System(GPS)

Provides info in 4 categories:1. Planning information2. Current status information 3. Historical information4. Responses to user questions

Global Positioning System(GPS) Information may be obtained from:

1. DOT/RSPA ATTN DMA 26 Room 8405 Washington, DC 205902. Commandant USCG Headquarters G-NRN-2 2100 2nd Street SW Washington, DC 20593

Global Positioning System(GPS) Information may be obtained from:

3. National Geodetic Survey NOAA; N/CG 142 Rockwall 306 Rockville, Maryland 20852

Global Positioning System(GPS) Satellites broadcast on 2 bands

L1 modulated with P code (Precise Positioning Service – PPS)

L2 modulated with C/A code (Standard Positioning Service – SPS)

C/A mode intended for general use and capable of providing single point positioning

P mode is much more accurate but is reserved for military and government use

Global Positioning System(GPS) Planning GPS Surveys – as important as

the sophisticated needed to collect the data

Planning Phases:Presurvey reconnaissance; 2 stations site requirements; 3 connections to existing geodetic control; 4 network design; 5 satellite availability; 6 observing schedule

Global Positioning System(GPS) Reconnaissance (presurvey)

Important to minimize delays or changes in observing schedule

1. Office planning1. Obtain station descriptions2. Prepare control diagrams

2. Preliminary Reconnaissance1. Determine recoverability of existing control stations2. Provide sketch showing existing and proposed

stations3. Suitability of existing stations for use by GPS

Global Positioning System(GPS) Station site Selection (critical factors)1. Obstructions with elevations greater than

15º-20º above horizontal should be avoided

2. Station mark must be suitable for occupation by tripod

Global Positioning System(GPS) Networks Design1. Design depends on

1. Surveys order and purpose2. Number of receivers available3. Desired spacing between stations

2. It is best to connect at least 3 existing geodetic control stations

Global Positioning System(GPS) Field Operations1. Survey team structure – determined

totally by operation method Numbers depends on:1. Number of receivers2. Number and length of observation stations3. Time spent transporting equipment4. Logistics and administrative needs

Global Positioning System(GPS)2. Transportation3. Monumentation4. Power supply5. Weather

Global Positioning System(GPS) Total Process:1. Establish receivers and have all track

simultaneously2. Data cleaned – search for ambiguities in

data to identify correct integer values3. All vector solutions are computed

1. 2-3 are accomplished by built in receiver computer4. Data given by longitude and latitude

New System: NAVSTAR L2C – civil signal – added to L2 with P code

Block II RM Satellites – Launch 2005-2009 L5 – New Frequency – more powerful and

larger bandwidth Provides easier signal acquisition and tracking Block IIF Satellites Functional in mid 2013

GPS Field Data Collection Techniques1. Static – minimum 3 receivers

Occupation/session 1-3 hours PDOP < 6 with 4 satellites Occupy 3 stations then move 2, leap frog techniques

2. Pseudo Static – can work with 2 receivers Occupy for 2-5 minutes, each station must be occupied

twice approximately 2 hours apart Can loose satellite lock for short periods PDOP < 5 with 4 satellites

GPS Field Data Collection Techniques3. Kinematics – 2 or more receivers

Occupy 1-3 minutes Must track same 4 satellites minimum prefer 5 1 rec. at base, rover occupies 1 min. move, occupy 1 min.

and at end go back to beginning and repeat4. Stop and Go Kinematics – 2 bases and 1 rover

Occupation time 1-10 sec PDOP < 6 with 4 satellites

5. Real Time (RTK) – base with radio transmitter and rover with radio receiver

Occupation 1-10 sec. PDOP < 6

Municipal Surveys1. Control Monuments and Associated Maps

1. Value: used by planners, engineers, architects, utilities, and surveyors

2. Planning Maps3. Steps of Fieldwork

1. Establish Network of Major Control Mon.2. Run traverse connecting major control points3. Run levels and establish BM’s along traverse

network

Order for project Monuments: Iron pin with bronze cap in 12’ dia

PCC and extending min 18” below frost line (min 48”)

Traverse: 1st order (1:200,000 – 1:500,000) Stations generally 1000’ – 1500’ apart

Leveling: base on NGS datum 3-wire differential most often used Avoid objects that are not permanent (fire hydrants, power

poles, etc.)

Products:1. Base Map – shows all control station,

traverse stations, BM’s, Streets, ROW, and Public Property

2. Topo Map3. City Property Survey (location of all

existing monuments)4. Underground Map (utility map)

Basic Route Survey and Design1. Concept for Route2. Reconnaissance Study

1. Small scale mapping of region (1”-500’ to 1”-200’)

2. Identify Alternative Routes (corridors)3. Corridor Study 4. Public Hearings on selected corridor

Basic Route Survey and Design3. Alignment Design

1. Preliminary medium scale mapping of corridor2. Paper location study3. Choose desired alignment4. Field location survey

1. Set PI’s2. Measure angle and distance between PI’s3. Choose and design curves4. Compute alignment5. Set centerline stations (Hubs at 100’ STA. + PC & PT)

5. Modify alignment if needed

Basic Route Survey and Design4. Roadway Design

1. Supplemental Large Scale Mapping1. Horizontal mapping2. Cross section baseline

2. Design typical sections3. Design roadway items4. Draft plans5. Compute quantities6. Prepare specifications

Basic Route Survey and Design5. Right of way surveys

1. Requires parcel and strip maps1. Determine ROW widths required2. Perform property surveys3. Prepare legal descriptions4. Stake parcels

Basic Route Survey and Design6. Construction surveys

1. Reference PI, PT, PC2. Slope stake for rough grade3. Stake drainage and structures4. Layout roadway items5. BlueTop for subgrade of final grade6. Progress measurements and cross sections for

pay quantities7. As built surveys

Sewer Projects1. Firm under contract2. Preliminary studies

1. General layout map2. Buildings located on general layout3. Treatment site search4. Preliminary paper layout

1. Make sure every building and potential building site can be served

2. Manhole system placed on general layout

Sewer Projects5. Preliminary filed work

1. Preliminary profiles1. BM system established2. Manholes set3. Profiles run4. Basement elevations acquired

2. Design mapping1. Final plans

3. Treatment area4. Boundary survey 5. Complete topo of area

Sewer Projects3. Design process

1. Sewer line design1. Preliminary profiles drawn

1. Basement elevations plotted2. Manholes placed on profiles3. Slope between manholes computed4. Problem areas – alternate service routes selected

1. Manholes set in field 2. Profiles run3. Revert to 3A

Sewer Projects2. Treatment plant design

1. Topo map prepared2. Type system verified3. Treatment system sized based on existing and

projected population4. System designed

3. Plans drafted1. Sewer plans normally prepared on plan/profile

sheets

Sewer Projects2. Treatment plant drawn using plan sheets and

cross sections3. Quantities computed4. Specifications

1. Written instructions on how every item to be built2. Include contract documents and bid proposal

4. Bidding procedure1. Notice of bid advertised on local paper2. Pre-bid meeting

Sewer Projects3. Bidding

1. Each contractor submits sealed bid2. Bids opened and tabulated 3. Engineer reviews proposals4. Engineer recommends which bid to accept

4. Contract awarded

Sewer Projects5. Construction

1. Surveying1. Contractor required to hire surveyor for stakeout 2. Manholes referenced3. Staking methods

1. Batterboard method2. Laser method

4. Measurement of quantities

6. As Built

Water distribution systems1. Put under contract – water district formed 2. Preliminary studies

1. General layout prepared2. Water district signs up users3. Water source located4. Waterlines placed on general layout

1. Hydraulic gradient plotted from USGS topo

Water distribution systems5. Pump station and water storage sites

1. Property acquired by perpetual easement or purchased2. Boundary survey performed for each site3. Topo each site

3. Field work1. Plan preparation

1. Normally photogrammetrically1. Flight plan sent on general layout2. Take photos and post measure horizontal control3. Plan sheets marked on photos using template

Water distribution systems2. Waterlines placed on plan sheets

2. Crossings and easements1. Every location where waterline crosses paved

road, railroad – has to be topo, cross sectioned, and tied to nearest stationing or milepost

2. Crossings plotted and permits applied for – railroads, state DOT, township and county roads

3. Easement descriptions prepared

Water distribution systems4. Final design

1. All waterlines and appurtenances on plans, easements, acquired and in docket form, rock excavation on plans1. Quantities computed2. System driven to make sure nothing missed

2. Tanks and P.S.1. Designed and sized2. Quantities computed

Water distribution systems5. Bidding 6. Construction

1. Water distribution system1. Waterline stakeout

1. Each easement plotted on plans2. Crossings as permitted staked

2. Quantities 2. Tanks and PS

1. Foundation staked2. Must be checked for plumb

7. As built

Architectural Projects1. Firm Under contract2. Preliminary fieldwork

1. Boundary survey1. Description provided2. Fieldwork

1. Monument search, traverse site2. Compute data and analysis3. Final stakeout

3. Easement and encroachment search4. Plat of survey

Architectural Projects2. Topo – grid method most common

1. Grid pattern 25’ – 100’2. BM – USGS3. Entire tract topo and adjacent areas to access4. Utilities – nearest tied in5. Include all objects above, on or below, ground6. Prepare topo map7. Field check map

Architectural Projects3. Construction

1. Control1. If large building – you may want to establish

TBM’s on control Mon.2. Stakeout

1. Convert architects dimensions to engineering2. Layout clearing and excavation limits3. Layout underground piping

Architectural Projects4. Layout footings and foundations5. Layout building corners and supports6. Locate roads and parking areas7. Locate lighting and other project extras

3. As built

Structure and Terrain Movement Used to monitor:

1. Movement of buildings ( x, y, and z)2. Movement of bridges3. Movement of dams4. Landslides and earthquakes5. Amusement park rides

Structure and Terrain Movement Description – error within system must be

less than smallest movement to be observed

2 groups of monuments installed1. Reference or control monuments2. Deformation or movement monuments

Structure and Terrain Movement Control – generally concrete pillars

extending 3-4 feet out of ground with tribrach permanently attached

Movement monuments – for earthquake or landslide may be similar deep monuments

Structure and Terrain Movement Equipment:

1. GPS2. Turned angles3. Angle/Distance4. Leveling