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CE115 - Civil Engineering Drawing and Spatial Analysis

Civil Engineering Drawing Pt 1:Plan Reading & Structural Drawings

Christopher M. Monsere, Ph.D., P.E.Assistant ProfessorPortland State UniversityDepartment of Civil and Environmental Engineeringmonsere@pdx.edu

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Outline

• Plan reading– Scale– Terminology

• Structural drawing– Steel– Concrete

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Plan Reading• Types of scales include:

– Engineers’ • Decimal• 10, 50, 20, 40, 30, 60

– Architects’• 2 scales per edge• Feet-inches• 1, 1/2, 1/4, 1/8, 3/4, 3/8,

3, 11/2, Regular, 3/32, 3/16

– Metric’

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Engineer’s Scale

1"3"30"30'300'

3 miles The Engineer's Scale expresses measurements as a ratio, dependingon the ratio assigned.

Actual Length

NTS: Not to scale

This means 30 gradations in the sale per inch

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Engineer’s Scale

1"

Actual Length

Given SCALE 1”=300’

There are always 10 gradations between units

660 feet

NTS: Not to scale

00 00 00

…then line that measures 1 actual inch represents 300 feet on drawing

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Engineer’s Scale

Given SCALE 1”=300’

NTS: Not to scale

325 feet

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Engineer’s Scale

NTS: Not to scale

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Don’t confuse 1:30 with 1”=30’SCALE 1”=30’

Paper Units : Actual Units

PU

AU=

1”

30’=

1”

360”= 0.0028

Reduction scale in ACAD

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Architectural Scale

• The scale

means how many inches per foot, so a ¾ scale means that ¾ inch equals one foot

• Each scale read from “0” closest definition

• Each unit represents 12 inches

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Architectural ScaleGiven SCALE 3/4”=1’

…this is a reduction scale..

Note this is always divisions of 1 foot. So, since this is sub-divided unit into 24 units. each 2 units is 1 inch.

This means ¾” = 1”

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Architectural ScaleNote that the sub-divided unit is divided into 12 units. Therefore, each unit is 1 inches.

Given SCALE 1/4”=1’

…then line that measures 1 paper inch represents 4 actual feet

It measures approx 14’-5”

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In-class Exercise

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Plan View (Top View)

Shows the horizontal alignment

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Stationing

• Given as:– STA + FT (or m)

• Typically: – stations in 100 ft or 100 m

• So the distance from STA 1+55 to 2+33– (assuming 100 foot stations)– (100-55) + (33) = 78 feet– OR– 233-155 = 78 feet

1 2 3

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Profile View (Front View)

Shows the vertical alignment

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Plan and Profile

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Slopes

• Angles sometimes given as V:H, read as “X on X” slope (RISE:RUN).

1V

5H

1:5

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Percent Slopes• Angles sometime given as % slope. A 2%

means for every 100 unit horizontal, there is a 2 unit change in the vertical.

2’

100’

-2%

2’

100’

+2%

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ElevationsA building elevation is typically labeled in relation to the compass direction it faces; the direction from which a person views it.

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Elevations

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Cross Section

Centerlines (CL) indicate center of alignment of structure

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Cross Section of Deck and HangersSource: Dorman Long (1932) Sydney Harbour Brige. Dorman Long & Co. Ltd., p35, http://sydney-harbour-bridge.bos.nsw.edu.au/engineering-studies/engineering-graphics.php

link

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Section View

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In-class Exercise• What if I don’t know

the scale or the drawing looks to have copied/zoomed, how could use a scale (ruler) to determine an object?

• Task: Make your own scale to measure the distance between DH-3-97 and DH-1-97

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Approximating scale

• Find a dimension on the plan sheet, measure it• Create your conversion based on PU:AU

PU

AU=

3.78”

76 m

So if I measure 3.15” on paper….

AU (m)=76 m

3.78 inPU (in)

AU (m) =76 m

3.78 in3.15 (in)

AU (m) = 63.33

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Structural Drawings• Structural drawings include:

– Foundation plans– Wall sections and framing details– Structural steel framing and details– Beam and column drawings and details

• Materials– Wood– Steel– Concrete– Masonary

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Approach

• Nearly all of the drawing principles that you have learned apply to structural drawing

• AutoCAD has “tools” built-in to help you draw elements faster

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Structural Steel• Two things to

design/draw– Structure

• Beams and columns

• Size, orientation, shape, length, placement

– Connections• Bolted, welded, or

riveted (not really used)

Colu

mn

Beam

Colu

mn

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Engineering design drawings

• Show the overall dimensions of the structure including:– Locations of columns, beams, angles and other

shapes– Sizes of structural members– Detail in the form of cross sections, special

connections required, and notes

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Structural Steel Shapes• Structural steel is

available in many standard shapes

• Most CAD programs have structural shapes symbol libraries available

Video Link

Nominally, depth and mass/unit, so shape is 14” tall 53#/ft

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Manual of Steel Construction

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Structural Steel

Plan View of One Floor

Dimensions in feet and inches, no ” symbol

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Shop drawings

• Consist of detail drawings of all parts of the entire structure showing exactly how the parts are to be made

• These drawings show all dimensions necessary for fabrication, usually calculated to the nearest 1/16”

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Piece Marks• A system is used to mark

each piece that is separately handled

• This mark is called a piece mark and should be shown wherever the member appears on the drawings

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Connections• Main members are joined together in the field

to build a structure and most joints are welded connections to the main members

• Riveting is seldom used as a connection but you may find reference to riveted joints in original plans

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Welding• Welding is a

common method for connecting steel members of buildings and bridges

• The principal methods of welding are:– Gas welding– Arc welding– Resistance welding

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Types of Welded Joints

• Butt joint• Corner joint• T-joint• Lap joint• Edge joint

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Types of Basic Welds & Symbols

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Complete Welding Symbol

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Fillet Welds

The arrow points to the joint where the weld is to be made. If weld symbol is below line, weld is made on leader arrow side. If above, opposite arrow. If both above and below, then both sides of joint.

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CAD Welding Templates

• Welding templates can simplify drawing welding symbols by hand

• They have all the forms needed for drawing the arrow, weld symbols, and supplementary symbols

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Simple Beam Connection

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In-class Exercise

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Has Design Been Constructed?

1. On sheet GW-34, mark locations of welds.

2. Review the WSDOT plans for the bridge. Based on the photos shown here, find as many clues that answer this question

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Concrete • Concrete is made by mixing sand, gravel,

or other aggregates with Portland cement and water

• Concrete is very good in compression, but weak in tension

• To solve this, embedded steel reinforcing bars are added to concrete– “Reinforced concrete”

• Prestressed concrete, – steel is pretensioned before the

superimposed load is applied

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Reinforced Concrete Drawings• Size of and shape of members

• Concrete material pattern shown in section

• Placement of reinforcing steel in section and plan views– Steel reinforcing shown as solid lines or filled

circles depending on view or section

AR-CONC HATCH pattern in ACAD

SOLID HATCH pattern in ACAD

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Reinforced Concrete Drawings

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Spiral Column Reinforcing

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Jackson School Road O’xing

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Jackson School Road O’xing

Bent 2

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Rebar Reinforcing Details