Dagnabbit, this is good stuff !!! SURVEYING ENGINEERING SURVEYS USDA - NRCS Construction Inspection for Field Office Activities 1
Objectives u Review of policy and guidance for proper note keeping and surveying procedure u Understand proper note keeping requirements u Understand the different types of surveys and the requirements for each of them u Understand layout and checkout procedures for different conservation practices Objectives 2
NRCS Policy National Engineering Manual (NEM) –Part 540 – Field Surveys National Engineering Handbook (NEH) –Part 650 – Engineering Field Handbook (EFH) – Chapter 1, “Engineering Surveys” 3 NRCS Policy
NEM General 4 “ Concise, accurate, and legible engineering notes are necessary to document planning, design, and construction. They provide the basis for expenditure of Federal and other funds for conservation installations. The National Engineering Handbook (NEH), Part 650, Chapter 1, “Engineering Surveys” provide the recommended format for engineering notes and related staking. ” NRCS Policy
NEM Responsibility 5 B. “ The information from basic staking of earthwork normally becomes the basis for measurement of payment quantities. ” NRCS Policy
NEM Format 6 “Each State Conservation Engineer (SCE) is to establish the format and minimum requirements for engineering note keeping based on the NEH. Engineering records are to be uniform to simplify training, improve clarity and overall efficiency, and allow consistency if personnel change through the course of a project.” NRCS Policy
NEM Format - continued 7 “B. Loose-leaf notebooks, special forms, or hard copies of downloaded electronic data may be used for recording engineering surveys, notes, and design data for onfarm conservation practices (Class I - V jobs) such as ponds, terraces, diversions, waterways, and animal waste management facilities. The documentation for the engineering surveys for conservation practices must provide the minimum information as outlined in the NEH.” NRCS Policy
NEM Staking 8 “A. Basic Stakes.—Basic staking is defined as alignment and grade stakes for structures other than embankments and channels. For channels and embankments, basic staking includes alignment and grade stakes plus slope stakes at the normal interval for the work. Normal interval is 100-foot stations on tangents and may decrease to as little as 25 feet on sharp curves. When construction pay quantities are determined from basic staking, a fair and equitable description of the ground surface is needed for the calculation of performance quantities. NRCS Policy
EFH Chapter 1, Engineering Surveys u Defined for Federal Government in 1925 as –1 st, 2 nd, 3 rd, and 4 th order accuracy –Generally, 3 rd and 4 th order accuracy is required for conservation work u 3 rd order accuracy is generally required for “Ordinary Surveys” u 4 th order accuracy is generally required for “Rough Surveys”
EFH Chapter 1, “Engineering Surveys”
Surveying Accuracy u Ordinary survey accuracy –Establishing Bench marks –Level circuits with 6 or more set ups –Surveys for complex structures such as concrete manure tanks u Rough survey accuracy –Generally used for most conservation work u Reference is Table 1-1, EFH Part 650, Chapter 1, “Engineering Surveys”
EFH Chapter 1, “Engineering Surveys”
Surveying Accuracy Terms u Survey Accuracy – The allowable error of closure of your survey notes. u Closure – Closing the survey at its origin or a point of known elevation in reference to the point of origin. u Proving the Elevation –Mathematical
Engineering Surveys
Engineering Surveys
Total Length of Circuit = 1 mile Allowable Error = 0.10 feet
Classroom Exercise #1 BM # TP # TP # TP # TP #4 2.08TBM #1 Error of Closure = Total Length of Circuit = 1800 ft Allowable Error = Complete Construction Surveys – Exercise #1 “Bench Level Circuit Note Keeping” exercise in the class problems section of the workbook. Assumed elevation of BM #1 is Find first HI by adding BS on BM #1. Find elevation of TP #1 by subtracting FS BM #
Level Circuit Example showing closure
Objectives u Review of policy and guidance for proper note keeping and surveying procedure u Understand proper note keeping requirements u Understand the different types of surveys and the requirements for each of them u Understand layout and checkout procedures for different conservation practices Objectives 20
Survey Field Notes u REMEMBER THIS! –YOU ARE DEVELOPING FIELD NOTES SO THAT SOMEONE NOT INVOLVED IN THE SURVEY, CAN READ, UNDERSTAND, AND UTILIZE THE NOTES FOR DRAFTING, DESIGN OR THEIR INTENDED PURPOSE. u Reference – EFH , Page 1-5
Developing Field Notes u Fill out a cover page u Fill in the top right hand side of page 2 with: Who and What they are doing, When, Where, Why, Weather, and Page #. u Use a 2H or 3H pencil or pen u Letter NEATLY! write as small as is legible, SKIP SPACES! DO NOT CROWD NOTES! u Do NOT erase, STRIKE ONE LINE THROUGH AN ERROR AND CONTINUE u Your notes MAY become a legal document or evidence. Take Pride In Your Work And Do It Correctly.
Typical survey plan for a Waterway or Channel R L Centerline WW Always look at increasing Stations to determine Left and Right from centerline
Actual survey notes from FO survey for waterways Anything Missing??
Topographic Surveys and Notes u Use a grid survey for simple areas on flat topography u Use handheld GPS and laser level in combination to map contour lines u Use total station or RTK GPS u Other? (LIDAR)
Objectives u Review of policy and guidance for proper note keeping and surveying procedure u Understand proper note keeping requirements u Understand the different types of surveys and the requirements for each of them u Understand layout and checkout procedures for different conservation practices Objectives 29
Why do we survey? u Conservation Practices –Inventory and Evaluation –Design and Layout u Guide for Construction/Quality Control –Construction Inspection u Measure Quantities/Certify for Payment –As-Built Plans
Technical Release (TR) 62 u No longer mentioned in the NEM or EFH Chapter 1 as a reference, but other chapters still refer to it: –Good reference for note keeping and layout –May be referenced in SOW or Documentation Requirements for practices –Some information has been incorporated into EFH chapter 1
Objectives u Review of policy and guidance for proper note keeping and surveying procedure u Understand proper note keeping requirements u Understand the different types of surveys and the requirements for each of them u Understand layout and checkout procedures for different conservation practices Objectives 32
Technical Release (TR) 62 u Layout of conservation practices –Based on practice measurement –Location only – flag line –Location by slope stake at no cut/no fill requires a baseline and elevation readings –Grid layout –Boundary layout
Class Exercise Practice nameSurvey accuracy (R or O) Layout method Irrigation Pipeline Pipeline Sprinkler Irr Waste Storage Micro-irrigation Pond Water Control Structure OrdinaryLocation Ordinary Location Rough? Ordinary Rough Slope stake Slope stake? Hint: From NEH Chapter 1, Ordinary Survey accuracy should be attained in establishing benchmarks, level circuits involving six or more setups, and surveys for drainage, irrigation, large channels, and other major structural practices.
Checkout of Practices u Checkout of conservation practices –Based on practice measurement –Found in Statement of Work (SOW) or documentation requirements –Unit of measurement and how to measure are usually detailed in specifications –Surveys for quantities
Slope staking procedures u Grade rod or elevation difference –Grade rod is HI – planned elevation –Grade rod is positive or negative (Important) –Grade rod – rod reading = Fill or Cut (negative is fill and positive is cut) u Trial and error to find toe location based on rod reading –Take rod reading at centerline u RTK GPS and slope staking software
Grade Rod
Construction Surveys Stakeout Example u Slope staking for a small embankment u Reference EFH Chapter 1, pgs 1-74 thru 1-86 and NEH 645 Appendix D, pg D-4 –Toe Dist = tw/2 + hs where –tw is top width – h is height of fill and – s is side slope
Slope staking example – Friendly Farmer GSS
Slope staking problem Construction Surveys – Stakeout Exercise BM #2 = BS = 6.04 HI = , Use Station 0+50 DS RR = 4.6 Fill Ht = 1.7 – 4.6 = -2.9 Since negative it is a fill Fill 2.9’ Offset distance = TW/2 +(SS * Fill) = 8/2 + (3*2.9) = = 12.7’ Grade Rod = HI – TOD – =
Example of Notes for Embankment Stakeout
Summary u See if you can answer the following: –Name 2 reasons you may need a turning point. –Do you add or subtract back sites? –(T or F) You take a back site to establish the height of the turning point or benchmark. –(T or F) For turning points or BM’s, you read the rod to the hundredth. Ground shots are read to the tenth. –(T or F) You always go R or L of a BL or CL looking toward increasing stations.