Construction Surveying & Layout

Contents

1 Introduction to Land Surveying, 9

The History of the U.S. Land Surveys, 10

Land Deeds, 14

2 The Building Site, 19

Type of Development, 20

Choosing a Site, 20

The Next Step, 24

3 The Survey, 25

Surveying Instruments, 26

A Practice Survey, 27

Closing, 30

Economizing in the Field, 34

4 Using a Transit and Tape, 43

Reference Lines, 44

Laying Out Roads, 51

Laying Out a Line, 51

Setting Parallel Lines, 58

Planning a Bridge, 61

5 Applied Geometry Using a Transit, 65

Using an Established Point, 66

Finding a Perpendicular Line, 66

Establishing Parallel Lines, 67

Dividing a Line Into Equal Parts, 68

Drawing a Tangent Circle, 69

Laying Out Angles, 70

Drawing a Circle Through Three Points, 73

Drawing a Hexagon, 74

Ellipses, 75

Pentagons, 77

The Involute of a Circle, 79

6 Stadia Surveying, 83

The Tools, 83

Geometry You'll Need to Know, 85

Practical Considerations, 92

7 Topographic Surveys, 95

Illustrating a Depression, 96

Making a Topographic Survey, 97

8 Leveling, 105

Leveling Instruments, 105

9 Basic Leveling Surveys, 109

Finding Elevations, 110

Types of Leveling, 112

Grade Stakes, 113

Potential for Error, 115

10 Complex Leveling, 117

Evaluating a Site, 118

Planning the Streets, 118

Grading, 123

Necessary Curves, 128

11 Surveying Notes, 145

12 Special Problems, 147

Finding Missing Measurements, 148

Subdividing Land, 162

13 Mapping the Site, 167

Mapping Procedure, 168

General Points, 169

Before Construction Begins, 170

14 Plotting Angles, 171

Using a Protractor, 172

Using Trigonometry, 172

15 True North, Latitude, and Longitude, 177

Locating True North, 178

Locating by Latitude and Longitude, 182

Appendix

A The Transit, 185

B Geometry for Construction, 193

C Trigonometry for Construction, 225

D More Practical Examples, 231

Index, 241

Preface

Your community library probably has several books on surveying. Many have been written. But nearly all are technical and detailed, offering far more theory and much greater depth than builders and contractors need. That's too bad, because most builders and many tradesmen need a working knowledge of basic survey principles.

On every job someone has to find or verify the location of lot corners, align foundation, walls and floors, lay out perpendicular and parallel lines, mark angles, set grade or calculate cut and fill quantities. Professional surveyors can do this work, of course. But you don't need to hire a professional to check a boundary line or lay out a driveway. After reading this manual, I think you'll agree that most of the survey and layout work on a construction site is relatively easy. Anyone with the desire and time available can master the skills required.

This manual should meet your needs precisely if you want to learn construction surveying and layout, but don't have the patience to wade through a detailed, theoretical surveying text. I'll emphasize the practical rather than the theoretical and focus on the type of survey and layout problems you're likely to face on your next job.

If knowing how to make a simple survey will help in your construction work, you're reading the right book. I'll cover all the practical surveying and layout you're likely to need for any construction project. If you're concerned that your math skills may not meet the challenge presented by the more complex survey problems, don't worry. I've simplified the trigonometry, geometry and mathematics throughout this volume. If you come to a symbol or calculation you don't understand, a little study of the appendix should clarify the point. Appendix B summarizes all the geometry you need to know and Appendix C explains the essentials of trigonometry.

Before we get into the first chapter, let me emphasize how important good survey practice is in construction. We've all heard sad stories about homes, apartments or garages that have been built on the wrong lot or straddling a property line. Fortunately, that's not a common error. But it's nearly always a very expensive mistake. Much more usual are foundations that aren't level, slab corners that aren't square, circles that are more like ellipses and ellipses that aren't like anything at all. These all begin with survey mistakes. But that's just the beginning. Anything that's not level, square and true in construction tends to affect every part of the job that follows. You begin with a foundation wall that isn't square at a corner and end up with roof sheathing panels that don't fit right.

The surveyor on the job has the first chance to make a mistake. If he (or she) does it right, the first error has to be made by someone else. Survey and layout that are done with care and professionalism promote craftsmanship throughout the project. What's the best way to be sure the survey and layout are done right? It's to do it yourself, or at least check it yourself. Maybe that's why some of the best, most successful contractors and builders I know have taken the time and trouble to learn construction surveying and layout.

Having said that, it's time to get down to business. We'll begin Chapter 1 by introducing land survey terms and concepts. By the time you've worked your way through this manual to the end of Chapter 15, I think you'll agree that construction surveying doesn't have to be difficult. There's nothing technical or theoretical here, but there's a lot to remember. Between Chapter 1 and Chapter 15 I'll explain it all, easily remembered.

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Chapter One
Introduction to Land Surveying

Land surveying allows a surveyor to precisely determine the area of any part of the earth's surface, the lengths and bearings (direction) of all the boundary lines, the contours of features of the land, and to accurately describe all of this information on a map.

A knowledge of surveying is indispensable if you are a builder, contractor, or developer. Not only will you often need to hire surveyors, check their findings, and read survey data and maps, occasionally you may be both the builder and the surveyor on a project. There's certainly no better way to find out about every aspect of the site you're developing.

This book describes the mathematics behind surveying, the instruments used to take measurements, the method for surveying a site, and the procedure for drawing accurate maps. You'll learn how to take complex measurements for roads, buildings, and bridges; how to establish grades for areas of cut and fill; and how to solve problems that may occur during a survey. The first thing you'll find out is how surveys actually started in the United States.

The History of U.S. Land Surveys

Land surveys made by government authority follow a definite system provided by law. These are United States Land Surveys. They began on May 18, 1775, when the Continental Congress called for a method of measuring and disposing of some lands claimed by the state of Virginia, which at that time included areas of West Virginia, Kentucky, and Ohio.

The Rectangular System

Accordingly, the Manual of Instructions for the Survey of the Public Lands of the United States was developed. It describes the conditions of the rectangular system of surveys that is required for U.S. land surveys.

Longitude and Latitude The rectangular system uses the longitude and latitude lines of the earth as its base. The longitude lines, called meridians, run north and south from pole to pole and at 90º to the equator.

Latitude lines, called parallels of latitude, run east and west around the earth parallel to the equator. The equator is 0º. Parallels of latitude are 90º north of the equator (north latitude) and 90º south of the equator (south latitude). Longitude and latitude are stated in degrees, minutes, and seconds.

Initial Points Under this system the initial point of a survey is referenced by longitude and latitude by astronomical methods, and marked accurately, called monumenting. This is done so that it's easy to identify exactly where the survey was started and, thus, exactly which piece of land is being described.

Initial points were established throughout the public domain by monumented meridian lines and baselines. Each meridian is identified by a name and number. These are listed in the manual of instructions.

All of the lines in the rectangular system are tied into or extended from these principal meridians and the baselines. They are identified as guide meridians and standard parallels, township exteriors, section lines, and meander lines (established by the water line of a lake or stream). In recent years, county officials have required that surveys be referenced to the legal comers of townships, and bearings and distances given in the deed (legal description) such that the surveyed area be satisfactorily closed by one of several methods ( which will be explained later).

Land Divisions The rectangular system was first used to survey Ohio. It began at the point where the Ohio River leaves Pennsylvania.

The public lands are divided into counties. Counties are divided into townships. Townships (6 miles square) are divided into 36 sections (1 mile square). Sections are divided further into quarter sections.

And, quarter sections are divided into quarter-quarter sections (see Figure 1-1). As always, there are a few exceptions to the rules. For instance, in Louisiana the word parish is used instead of county. And, sometimes townships aren't divided into exactly 36 sections.

A county contains townships, and a north-south row of townships constitute a range of townships. An east-west row of townships constitute a tier of townships. Figure 1- 2 shows the arrangement of the 36 sections in a township.

Figure 1-3 illustrates the political subdivision of land. The township boundaries running north and south, as ab, are intended to be true meridians and are called meridional boundaries. A series of townships in a north-and-south row constitute a range of townships. Therefore, the meridional boundaries are commonly known as range lines .

Townships are numbered as ranges in both east and west directions. Here they run west from the principal meridian, hence the letter W. Townships also are numbered as tiers both north and south, beginning with number one at the baseline.

You can see that Jackson Town-ship in the northwest corner is in Range 19 West (R-19-W), and in Townships (tier) North (T-7-N).

Look north to south along the west county line. You’ll see an example of mixed section numbering shown along the Jackson and Liberty townships. In Jackson Township, section 19 has a section 20 on either side of it. Section 30 has a section 31 on either side of it. This seemingly odd-numbered section is due to a land trade made with Pike County many years ago. You'll find this jumbled numbering in many places. There are localities in Ohio where the range lines run east and west and the township tiers run north and south. And, some townships there contain 25 sections instead of 36 sections. So, when you're researching area records, look out for the unusual.

Land Deeds

This rectangular system of surveying with official requirements was created because surveys are used as the basis for the land descriptions used in deeds. A deed is a legal document describing a certain piece of land that you own. So, if everyone used a different method of surveying for describing that land, no one would be sure who owned what.

Deeds describe the initial point of the survey and use bearings to describe the boundaries of the land in question. Figure 1-4 shows how a survey plane is divided into four quadrants, each 90º. The bearing is then referenced for every case, from the north-south line. For instance, bearing N30ºE runs north by east 30º from the north-south line and bearing S30ºW runs south by west 30º from the north-south line.

Suppose that you are about to buy a piece of land in the northwest area of the south half of the township shown in Figure 1-3, which is in Range 19 West of Jackson Township. You and the owner have visited or driven around the area you plan to buy. You then hire a surveyor to describe the boundaries of that piece of land. Your deed to the land will be written from the description made by the surveyor.

Since this parcel of land is in the northwest quarter (NW 1/4) of the southwest quarter (SW 1/4), the introductory paragraph of your land deed will read:

Being a parcel of land in the NW 1/4 of the SW 1/4 of Jackson Township, Jackson County, Ohio, R-19-W, T-8-N.

You can see the T-8-N (Township Eight north) on the south line of the township. This is an accurate legal description, written from a correct survey, that identifies this parcel of land from any other parcel anywhere on earth (See Figure 1-1).

To make it even better identified, the survey is tied to an initial, permanent point (described previously). In this case, the legal comer (any comer of a political subdivision) provided by the northwest comer of the NW 1/4 of the SW 1/4 of Jackson Township, is a perfect reference point for the survey of your land. Therefore, the legal description following the introductory paragraph in your deed reads as follows.

Beginning, for reference, on a stone at the NE comer of the NW 1/4 of the SW 1/4 of Jackson Township,

Thence 500 feet due south along the east line of said 1/4-1/4 to a point in said line;

thence 356 feet due west to an existing fence comer, said comer being the place of beginning for this survey.

thence N84º23'W along a fence line a distance of 165 feet to a point in said fence line;

thence S5º19'25.51";W a distance of 276.66 feet to a point in an open field;

thence S84º23'E a distance of 165 feet to a point in an open field;

thence N5º19'25.51";E a distance of 276.66 feet to a point, said point being the fence comer at the place of beginning for this survey, said survey containing 1.05 acres, more or less.

Notice that in descriptions of a survey bearing, the words north, south, east, and west, are not used alone. For instance, the bearing on the east line of the 1/4-1/4 (Figure 1-5), is described as being "due north." This is the back bearing for the bearing given as "due south" in the deed description. Always use the word "due" with the cardinal direction.

Now you know how surveys began and how they are used to write deeds. The next step is to find out how to do a survey using the instruments and methods described in the following chapters.

Construction Surveying and Layout
by Paul Stull

Every construction project requires leveling, measuring, layout, surveying and setting grade. But until now there was no practical manual for builders that explained construction surveying in simple language. This handy reference was written to help builders, contractors and developers understand this important subject so they can handle more of their own survey and layout work.

If you've been paying professional surveyors to make simple surveys, guessing about boundaries, or have had trouble making accurate layouts, this valuable reference will save you time and money - and help avoid expensive mistakes. It explains all the surveying a construction contractor is likely to need: How land is divided, how to use a transit and tape to find a known point, lay out an angle, curve, circle, perpendicular or parallel lines; how to draw an accurate survey map from your field notes; how to use topographic surveys; the right way to level and set grade; how to align foundations, walls and floors; how to find or check lot corners. It shows how to make a survey for any residential or commercial lot, driveway, road, or bridge - including how to figure cuts and fills and calculate excavation quantities.

Whether you want to make your own layouts and surveys or just read, understand and verify the accuracy of surveys made by others, you should have this practical guide.

Paul Stull, Ph.D, P.E., P.S., is a consulting engineer and land surveyor with over forty years of experience in the construction industry. He's laid out hundreds of subdivisions, roads, bridges, sewer lines, industrial plants and property lines and for eight years taught surveying to tradesmen in Jackson, Ohio. He's active in the Ohio Society of Professional Engineers and Surveyors and has served as chair of the administrative, educational and legislative committees for that organization.