intro civil eng

7/28/2019 Intro Civil Eng

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Civil Engineering is the oldest of all engineering fields. The earliest practices are

believed to be between 4000 and 2000 BC. The construction of Pyramids in Egypt (circa

2700-2500 BC) might be considered the first instances of large structures. CivilEngineering projects help support society or civilians by making roadways, bridges and

dams.

Civil Engineers deal with the design, construction andmaintenance of the environment, both natural and manmade.

Land Development engineering converts raw land into usable

forms.

Much of Civil Engineering begins with a Survey. GPS AERIAL LiDAR- light detection & radar.

Points are imported into CAD to create Triangulated Models – triangles are created to represent ground surface. The DTM – digital

terrain model is then stored in a file called a TIN.

The point information is then used to improve or create: Roadways

Site Development Parking lots Golf Courses

Airports

Subdivision design Hydrology analysis More . . .

Be prepared to learn new terminology. This terminology has remained the same over theyears and perhaps sounds strange at first, but once you understand what it stands for the

rest is easy.

We are going to put in a lot or a home site using Civil Engineering terms.

Open up A+CAD

The first thing we need to do is change our units to

SURVEYERS units.

Type in UNITS at the command line and pressENTER to get the following dialogue box.

http://en.wikipedia.org/wiki/Egyptian_pyramids

http://en.wikipedia.org/wiki/Egyptian_pyramids



Page – 2

Answer 2 for decimal units

Change places to 8 because of theterminology we will use needs that many places.

Change to SURVEYOR’s UNITS or 5with 8 decimal places as well.

Default to E (east) being 0 and measuring

clockwise.

We are going to draw a LOT that is approximately 100 x 150 so we need to set a sheet

size large enough for the LOT.

At the command line type in:

LIMITS and press ENTER.

Leave the lower left hand corner

of the page at 0,0 so just ENTER.

Change the upper right hand corner to 300,250 because we want plenty of space to drawthe lot.

Zoom extents to “home up the screen”.

Select POLYLINE to begin drawing the LOT.

Select a beginning POINTon the screen by using your

LEFT MOUSE BUTTON.

Move away from that point

and tap the f5 for functionkey 5 until your coordinate

display looks like the one at

RIGHT.



Page – 3

We are going to use RELATIVE coordinatesor related to the point we just picked.

Type in at the command line: @100<Nand press enter.

What we are saying is we want to go 100

feet at an angle of NORTH.

Should look like display at right. Note that

the second line is not connected, just rubber banded away.

NEXT POINT:

@150<S81D32”E press enter

which means we want to go 150 at andangle of South 81 Degrees 32 seconds

East.

You are using CIVIL terminology here

and note that the entire earth is setup like

this.

Last line is:@150<S13D33’20”E press enter

This means we are going 150 feet at anangle of South 13 Degrees 33 minutes 20

seconds East. Type in CL to close.



Page – 4

This is also calledLEGAL terminology.

This is from a typical lotdrawing.

Notice the terminology.

With just this shortlesson you can now

understand the

annotation of the

drawing a little bit better.

A great reason to

use a POLYLINEis that you can

EASILY

calculate

GEOMETRYfrom the drawing.

Type in LI (shortfor LIST) and

select the LOT

and press enter.

While this might give you more information that you really want it does give you AREA

and PERIMETER information. So if an ACRE is 43,560 sq feet this lot is less than a half

acre.

Close A+ CAD



Page – 5

Find the Bentley Power Civil Icon and load the program.

Civil Engineers do not usually create the original geometry they work with, but mayimport data from a data collector or work with a drawing that originated elsewhere. Civil

Engineers work with dirt. When a roadway is built, depending on the terrain, they have

to haul dirt to fill in areas and remove dirt in others (this is called cut and fill). In order todetermine slopes and how much dirt to move they get xyz points and store them in a data

collector. This information is then transferred into a computer and with a civil

engineering program. The points are brought into the program and are

TRIANGULATED – like connect a dot, to calculate this information. There will be anerror ratio, but they calculate this in as well.

If you have never done so, today you will see your first TRIANGULATED CivilEngineering file.

We are going to

open an existing filecalled

COUNTOURS.

Your screen shouldlook something like

this one.

If you get themessage on

units just select OK.

The file is really nested. You

need to go to DATA and thenGEO and then SITE and then

SITE1 and then CHAPTER 8

and you should see the

drawing to open as shown atright.



Page – 6

You may see this screen. If so, SELECT NO.

Select OK to change units if youreceive this display and close the

ELEMENT SELECTION dialogue

box.

This is a

contour map

showing

major and

minor countours

of an

island.Think of

this as the

Big Islandin Hawaii.



Page - 7

We need to change thecontours into

information the

program can use or aDTM (digital terrainmodel). In order to do

that we need the DTM

tools.

Select the CIVIL

pulldown and the

DIGITAL TERRAINMODEL

Select DTM from the

SMALL menu bar andthen EXTRACT from the

larger one.

Select GRAPHICS

Type in the name of

our new DTM file weare going to make or

GROUND.DAT

Make sure the

decimal places andeverything matches

as at right.

Select MATCH andthen SELECT a

MINOR contour by

picking it with your left mouse button.



Page – 8

Select MATCH one more

time. This time select aMAJOR contour line.

Select the ICON to theRIGHT of LvNames and

check Exist_Cont_Major

and Exist_Cont Minor.

Select OK.

Select DISPLAY and it will then turn to

UNDISPLAY



Page – 9

Select FIT VIEW to home up the display.

Select APPLY. Make sure

the Extract is set to View 1

Congratulation we have now

made a file calledGROUND.DAT.

Close the EXTRACT

GRAPHICS dialogue box.

As mentioned earlier calculations are made using

a triangulated method. This software cantriangulate using points as well as contours. Let’s

get to work and build some triangles.

Select BUILD TRIANGLES from the DTM tool bar.

We are going to use our ground.dat file to create a

ground.tin (triangulated) file. Make sure everything

matches the dialogue at right and select PROCESS.



Page-10

We will now take a look at our TIN file and assign what

we want to see and colors for that data.

Select the LOAD DTM feature.

Make sure to use our

ground.tin file and that

the information isexactly as shown at

right.

Double click to turn on lines and labels

and then select LOAD.

This is a TRIANGULATED FILE.

Do not CLOSE this DIALOGUE BOX

as we are using in DISPLAY only mode

and the DISPLAY WILL CHANGE.Use the MINUS at the top to diminish

it.



Page-11

At this point the operator couldedit this file and add, move, or

insert more vertexes as needed

and update the file.

You can also do ANALYSIS of this file.

Note how many different options are under

Analysis.

Select PROFILE. WE want to see how the

Island varies in elevation in specific areas.

Civil Engineers usually do a PROFILE of an EXISTING CONDITION and then another

PROFILE of the change.

SELECT the MAGNIFER and then our file

GROUND.TIN and OPEN.



Page – 12

Select ADD FEATURE button

and our file will appear.

Select CREATE PROFILE.

Select PROFILE ELEMENT.

REDRAW the screen.



Page – 13

Choosethe

selection

toolshown atright and

then pick

two points on

contour

as

shown.

That is a steep elevation. Right click on your mouse to try another area.

You can

clearly see

that there

aremountains

that slope

to the sea.

If you find Civil Engineering interesting there are amazing jobs in the public or private

sector. If you want to continue on refer to the PowerCivil Training Guide that came with

The CAD Academy and start on Chapter 9.

Lesson is complete

intro civil eng

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