Civil Engineering Surveying

Name: Civil Engineering Surveying
Uploaded: 2017-08-20T14:54:55+00:00
Duration: PTM32S6
Channel: Shon Allen
Description: Civil Engineering Surveying

Civil Engineering Surveying
Adapted from: Roy Frank

Planning A Survey Planning requires a well rounded understanding of surveying practices Process: Choice of accuracy required (depends on use to be made) Basic Control Topographic Photogrammetry

Planning A Survey Existing Control Reconnaissance:
Search records for existing control in area Illinois Geological Survey – Urbana, IL National Geodetic Survey – Rolla, MO or Rockville, Maryland Reconnaissance: Search Procedure: Description often dated Can use GPS receiver (Lat. And Long) Probe, detectors – often problems - brass

Planning A Survey Choice of Instruments and Methods
Depends on availability, location, existing features, and accuracy Computation and Drafting

Accuracy and Errors Accuracy depends on:
Precise instruments Precise Methods 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 Blunder is a mistake, to help eliminate: Blunders
Systematic Error Accidental Error Blunder is a mistake, to help eliminate: Every value to be recorded must be checked by some independent field observation

Errors Once check indicates that there is no blunder, field record must never be changed or destroyed 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: All surveying equipment must be designed and used so that whenever possible systematic errors will be eliminated automatically 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 Surveys Surveys and mapping of bodies of water and shorelines Rivers and Lakes – Process different Rivers Normal process is to establish 2 parallel lines of control points on opposite sides River Portion: 2 processes EDM similar to radial Dual instrument with position by angle and intersection Lakes Normal process same as river but generally do not have current problems

Overall Process: Establish control points both horizontal and vertical
Preplan where sections are to be taken (this is basis for control points on shore) Cross sections taken If EDM, radials taken from control points due to difficulty in obtaining shots under 300’ 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: Establish system of BM’s throughout area gauges will be installed Establish elevation mark at site for installation After gauges are installed, check elevation of each

Topographic Surveys 6 Basic Methods Radial Plus/Offset Plus Offset
Establish baseline (Often centerline), establish points at station interval 50’, 100’, 200’ Tie planimetric data by distance down line plus distance right or left (looking up stationing) Establish elevations on station points then elevation out a predetermined distance with shots at breaks

Topographic Surveys Grid Method
Due additional section to locate features in between stations Equipment: Tape, Level, Rod, Transit, - Right Angle Prism? Grid Method Take cross Section Groups and Combine Establish Grid baseline – often property line Establish Perpendicular line Both Marked at grid interval (25’, 50’) Planimetric tied plus/offset in each grid Grid laid out by double taping Field notes 1 – 2 grids/page

Topographic Surveys Photogrammetry Limitations
Trees – Leaves off – no large growths of coniferous Ground Cover – grass, thick weeds and vines, snow Clear Sky 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 Surveys GPS: Total Station System Basic of GPS
Topo with GPS Topo: Trimble Total Station (RTK) Limitations: Must be able to maintain satellite signal – Trees, Building Signal Reflection (Multipath) – Buildings, Fences, Roofs Debate over elevation (0.15’ +/- my belief)

Topographic Surveys Trace Contour Plane Table Surveys
Used to identify several contours around an area Plane Table Surveys Rarely used Method prepares a manuscript map in the field

Mapping and Map Drafting
2 Basic Types of Maps used in Engineering Line Drawing Photogrametrically prepared manuscript or orthophoto map

Datum in Mapping: Datum used to correlate measurements, to determine elevations and horizontal positions for points at different locations Topographic Maps using Symbols Show: Spatial configuration of Earths surface (contours) Natural Features (Lakes, Rivers, etc.) Physical Changes caused by man

Planning Maps Used in planning Engineering work or overall planning at the urban, Regional, or National Levels Plotting Contours: Interpolation: Estimation Computation

Contours Characteristics of Contours: Horizontal distance between contour lines is inversely proportionate to the slope Uniform slopes have contours evenly spaced Along plane surfaces (manmade) contour lines are straight and parallel Contour lines are perpendicular to lines of steepest slope All contours close upon themselves Different contours do not merge or cross one another (except vertical walls, overhangs, cliffs) on map

Factors that influence choice of map scale Clarity with which features can be shown Cost (larger scale – higher cost) Correlation of Map data with related maps Desired size of map sheet Physical factors (number and character), nature of terrain, required contour interval

Map Classifications Based on American Society of Civil Engineering, Surveying, and Mapping Division Design Maps: Used to design and construct Information shown on Maps:

The following should be on a map: Direction of Meridian (North) Graphical Scale (Bar in case of reduction) Legend or key of symbols Title Block (identifiers) Contour Interval Datum to which both Horizontal and Vertical are Referenced If coordinate base used – what system

If map is to become public record (subdivision). It must contain in addition to the above: Length of each line Direction of each line (bearing or angles) Subdivision numbering system (lot and block) Location and Kind of monuments Names of property owners (on site and adjacent) Full description of Boundary Certificate of Surveyor that map is correct

Planning and Estimating from Topo Maps
Purpose of Topo maps Profiles Grade contour Drainage Area Limits determined by following characteristics: Begins and ends at the point in the stream to which it applies Passes through every saddle that divides drainage area Often follows ridges Reservoir Capacity

Earthwork Computations by Average End Area
Prepare 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: = (100/27)/ 2 = {(Sta. Dist.)/ [CF/CY]} / 2

Earthwork by Average End Area
EARTHWORK BY AVERAGE END AREA (EXAMPLE) END AREAS: STATION CUT EMBANKMENT

SAMPLE END AREA STATION SUM SUM
CUT FILL CUT FILL D/ CUT FILL CUT FILL CUT: 570 X = 1056 Cubic Yards EMBANKMENT: 5574 X = Cubic Yards Compaction Factor = 25%, CY X 1.25 = CY Fill

U.S. Rectangular System “IDEAL” Process:
Area divided by establishment of Principal Meridians and Baselines Area divided into 24 mile square tracts quadrangle using guide meridians and Standards of Parallel (correction lines) Divide 24 mile² tracts into 16 townships each 6 miles square 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: Access (ingress/egress) Construction Water rights Utility

Easement must Describe
What it is for (purpose) Who between Must be signed by all who’s name appears on deed Width of easement Duration – specified number of years or perpetual or life 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: Professional Commercial Recreational

Provides info in 4 categories: Planning information Current status information Historical information Responses to user questions

Information may be obtained from: DOT/RSPA ATTN DMA 26 Room 8405 Washington, DC 20590 Commandant USCG Headquarters G-NRN-2 2100 2nd Street SW Washington, DC 20593

Information may be obtained from: National Geodetic Survey NOAA; N/CG 142 Rockwall 306 Rockville, Maryland 20852

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

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

Reconnaissance (presurvey) Important to minimize delays or changes in observing schedule Office planning Obtain station descriptions Prepare control diagrams Preliminary Reconnaissance Determine recoverability of existing control stations Provide sketch showing existing and proposed stations Suitability of existing stations for use by GPS

Station site Selection (critical factors) Obstructions with elevations greater than 15º-20º above horizontal should be avoided Station mark must be suitable for occupation by tripod

Networks Design Design depends on Surveys order and purpose Number of receivers available Desired spacing between stations It is best to connect at least 3 existing geodetic control stations

Field Operations Survey team structure – determined totally by operation method Numbers depends on: Number of receivers Number and length of observation stations Time spent transporting equipment Logistics and administrative needs

Transportation Monumentation Power supply Weather

Total Process: Establish receivers and have all track simultaneously Data cleaned – search for ambiguities in data to identify correct integer values All vector solutions are computed 2-3 are accomplished by built in receiver computer Data given by longitude and latitude

New System: NAVSTAR L2C – civil signal – added to L2 with P code
Block II RM Satellites – Launch 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 Techniques
Static – minimum 3 receivers Occupation/session 1-3 hours PDOP < 6 with 4 satellites Occupy 3 stations then move 2, leap frog techniques 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 Techniques
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 repeat Stop and Go Kinematics – 2 bases and 1 rover Occupation time 1-10 sec PDOP < 6 with 4 satellites Real Time (RTK) – base with radio transmitter and rover with radio receiver Occupation 1-10 sec. PDOP < 6

Municipal Surveys Control Monuments and Associated Maps Planning Maps
Value: used by planners, engineers, architects, utilities, and surveyors Planning Maps Steps of Fieldwork Establish Network of Major Control Mon. Run traverse connecting major control points 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: Base Map – shows all control station, traverse stations, BM’s, Streets, ROW, and Public Property Topo Map City Property Survey (location of all existing monuments) Underground Map (utility map)

Basic Route Survey and Design
Concept for Route Reconnaissance Study Small scale mapping of region (1”-500’ to 1”-200’) Identify Alternative Routes (corridors) Corridor Study Public Hearings on selected corridor

Alignment Design Preliminary medium scale mapping of corridor Paper location study Choose desired alignment Field location survey Set PI’s Measure angle and distance between PI’s Choose and design curves Compute alignment Set centerline stations (Hubs at 100’ STA. + PC & PT) Modify alignment if needed

Roadway Design Supplemental Large Scale Mapping Horizontal mapping Cross section baseline Design typical sections Design roadway items Draft plans Compute quantities Prepare specifications

Right of way surveys Requires parcel and strip maps Determine ROW widths required Perform property surveys Prepare legal descriptions Stake parcels

Construction surveys Reference PI, PT, PC Slope stake for rough grade Stake drainage and structures Layout roadway items BlueTop for subgrade of final grade Progress measurements and cross sections for pay quantities As built surveys

Sewer Projects Firm under contract Preliminary studies
General layout map Buildings located on general layout Treatment site search Preliminary paper layout Make sure every building and potential building site can be served Manhole system placed on general layout

Sewer Projects Preliminary filed work Preliminary profiles
BM system established Manholes set Profiles run Basement elevations acquired Design mapping Final plans Treatment area Boundary survey Complete topo of area

Sewer Projects Design process Sewer line design
Preliminary profiles drawn Basement elevations plotted Manholes placed on profiles Slope between manholes computed Problem areas – alternate service routes selected Manholes set in field Profiles run Revert to 3A

Sewer Projects Treatment plant design Plans drafted Topo map prepared
Type system verified Treatment system sized based on existing and projected population System designed Plans drafted Sewer plans normally prepared on plan/profile sheets

Sewer Projects Bidding procedure
Treatment plant drawn using plan sheets and cross sections Quantities computed Specifications Written instructions on how every item to be built Include contract documents and bid proposal Bidding procedure Notice of bid advertised on local paper Pre-bid meeting

Sewer Projects Bidding Contract awarded
Each contractor submits sealed bid Bids opened and tabulated Engineer reviews proposals Engineer recommends which bid to accept Contract awarded

Sewer Projects Construction As Built Surveying
Contractor required to hire surveyor for stakeout Manholes referenced Staking methods Batterboard method Laser method Measurement of quantities As Built

Water distribution systems
Put under contract – water district formed Preliminary studies General layout prepared Water district signs up users Water source located Waterlines placed on general layout Hydraulic gradient plotted from USGS topo

Pump station and water storage sites Property acquired by perpetual easement or purchased Boundary survey performed for each site Topo each site Field work Plan preparation Normally photogrammetrically Flight plan sent on general layout Take photos and post measure horizontal control Plan sheets marked on photos using template

Waterlines placed on plan sheets Crossings and easements Every location where waterline crosses paved road, railroad – has to be topo, cross sectioned, and tied to nearest stationing or milepost Crossings plotted and permits applied for – railroads, state DOT, township and county roads Easement descriptions prepared

Final design All waterlines and appurtenances on plans, easements, acquired and in docket form, rock excavation on plans Quantities computed System driven to make sure nothing missed Tanks and P.S. Designed and sized

Bidding Construction Water distribution system Waterline stakeout Each easement plotted on plans Crossings as permitted staked Quantities Tanks and PS Foundation staked Must be checked for plumb As built

Architectural Projects
Firm Under contract Preliminary fieldwork Boundary survey Description provided Fieldwork Monument search, traverse site Compute data and analysis Final stakeout Easement and encroachment search Plat of survey

Topo – grid method most common Grid pattern 25’ – 100’ BM – USGS Entire tract topo and adjacent areas to access Utilities – nearest tied in Include all objects above, on or below, ground Prepare topo map Field check map

Construction Control If large building – you may want to establish TBM’s on control Mon. Stakeout Convert architects dimensions to engineering Layout clearing and excavation limits Layout underground piping

Layout footings and foundations Layout building corners and supports Locate roads and parking areas Locate lighting and other project extras As built

Structure and Terrain Movement
Used to monitor: Movement of buildings ( x, y, and z) Movement of bridges Movement of dams Landslides and earthquakes Amusement park rides

Description – error within system must be less than smallest movement to be observed 2 groups of monuments installed Reference or control monuments Deformation or movement monuments

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

Equipment: GPS Turned angles Angle/Distance Leveling

Civil Engineering Surveying

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