09/03/2004/Apinya/KMUTTarc354slope analysis031 TOPOGRAPHY earth shape and earthwork Interpreting the...

09/03/2004 /Apinya/KMUTTarc354slope analysis03 1

TOPOGRAPHY earth shape and earth

work Interpreting the topo graphic contour

planSlope analysis

Grading grading for circulation


Topo graphy map Construction of a slo

pe profile from a top ographic contour ma

p

Contour interval: the height between each contour line.

Cross section of that shape

X axis represents distance, Y axis represents level change


Slope profile show s landform

What is landform?

Topography map :

Slope form


Topography map : Slope form

Convex slope Erosion


1. Same elevation on one ccccccc cccc and same level change in between each contour line. (called contour interval)

2. .Every contour closes on itself 3. A summit cc depression ccccccccc cc ccc cccccccc

cccccccc cccccc ccccccc,. 4. .Contour lines never cross 5. c cccccc sloping surface 6. Convex ccccc 7. Concave ccccc 8. ccccccc 9. Steep slope

10. Relatively level. 11. Ridge

Topography map:

contour characteristics


Topo graphic model

Models are good mediums to give the feeling of the earth form and study the natural drain age pattern


Drain age pattern 90Natural drainage pattern : Water always flows in degrees

cc ccccccc ccccc cccccc ccccc ccc cccccccccc cc ccccccc c. - ar ge scal e dr ai nage pat t er n besi des t he on si t e t opogr ap

hy to see how much water flow through the channel .


Grading formula G=D/L or L=D/G or D=GL Gradient percent = D/L*100

Map ping slope from Top ography map


208Slope analysis of . acr ccccc ccccccc cccc. c the usc cc ccccccccc ccccc ccc c cc

ping slopes from a contour m.

Interpret ing slope


Interpret ing slope


Slope criteria

Suitable & recomm ended slope for eac

h use concerningmobility, possible c

-ut fill,maintenance and drainage abilit

y.


Slope criteria

Angles of repose for various types o

f slope materials. ( Angles are given i

n degrees.) What is Angles of repose?

Maximum angle fo r earth material th

at it can be incline d, and it will fail if

beyond.


Grad ingGrading : is the act of remodeling the land form. It is

one of the most important items in site planning, l andscape design and construction. Grading serves

three main purposes: 1.To create a level to put something on; for a hous

e, car, sport play field, a hotel, etc. 2. To create circulation ways; road way, loading ra

mp, handicapped ramp, bicycle track, etc. 3. To create special effect and solve special proble

m; makea mound t o hi de par ki ng l ot or r educe sound, p reventer osi on and l andsl i de, aest het i c or psycholo gicalpur poses.


Grading making an area level to put so

mething on By cut ting only

t he soi l i s st abl e r equi r e l ess cost f or

f oundat i on const r uct i on

be able to do very stee p slope

cost to transport earth from the site


Grading making an area level to put

something on By fill ing only

easier to make a very l evel elevation

good for low land, flood problem area.

cccccccc cccccc ccccc c ccccccccccc Cost of transporting ear

th into the site



something on

By the combi nation of cut an d fill

balance earth in the site, n o transportation cost.


Grading making an area level to put so

mething on By the combi nation of cut and fi

ll: plan of slab on sloping topography


Desi gni ng a l evel pl ane

on steeply slopingsi te.

Source: LANDSCAPE ARC HITECTURE, John Orm

sbee Simands.


something on


Gradingwhen not to grade

Avoid grading on the following conditions 1. Grading that results in radical loss of veget at i

on and t opsoi l 2. Grading that interrupts the natural dr ai nage 3. Grading that results in aest he t i c degr adat i o

n 4. Grading on di ff icult slopes (excess of 25%) 5 . Grading in envccccc ccccc cccccc cccccccccc ccc

odplain, bogs, 6. Grading in areas effected by natural cccccccc ;

mudslides or along earthquake fault lines


Grading for circulation

Circulation routes should be level as possible. c wo ways to travel up ccccc ccccccc ( max imum slope for local street is 8%)


The normal grading method is something between the t wo extremes with roads or paths climbing and falling ge

ntry so as to allow the quickest trip with the least effort.

Gradingfor circulation


Circulation routes crossing level country are relati -- vely easy to grade providing uni form surface and assuring the roadway dr ai n s properly.

Auni f or msur f ace means smoot hi ng out t he bumps by spacingcont our s evenl y.

Drainingthelevelroadsomet i mes r equi r es cr eat i ng ar t i fi ci al hi gh an dlowpointsforwat er fl owdi r ect i on. These can be shown gr aphi c allywithcontours, spot el evat i ons, or sect i ons.


Section through road with CROWN Road sloped from side to side


Shortest distance but results extensive cutting, common design guide is to align the road centerli

ne with or parallel to the contour lines with minim al grading



When gr adi ng byCUTting , begin with t

he lowest contour an d work up, by fill ing,

begin with the top co ntour and work down.

Contours are spaced according to the grad

ient of the proposed r oute typically expres

sed in percent. For 10 % slope, one meter in

terval contours would be spaced 10 m. apar

t



Themost common way i f exi st i ng t opogr aphy i s NOT t o st eep. The procedure is to select the contour in the mid dle of the ro

ad and cut half the contour above, fill half of the contour belo w.



If cut/fill creates a steep bank, a heavy rainfall can induce mudslides and erosion. Alter natives to separate the road w

ay (if it is wide enough) should be considered along with th e use of retaining wall on the high side of the slope.



The r oad cr osses a ser i es of cont our and causes a ver y st eep bank si nce t h

e r oad needs UNI FORMslopedesi gn cr i t er i a. The situationshoul d t hen avoi d or t r y t o compr omi set he cut and fi l l al ong t he cent er l i n e.



Road crosses drainage swal e, the problem concerning t he i nt er section between ro ad and topographical depres

sion, theuse of BOX CULVERT or BRI DGE would be chosen depen

d on the length and depth of the swale and the image of t

he design.



Ref erence books 1. Grade Easy, 2 . Site Planning : Environmental process and developme

- 129171 07632nt P. , R. Gene Brooks, Prentice Hall N.J. 3. Site Planning p.83-106, Assoc.Professor Decha

Boomkum, Lecture sheet , Chulalongkorn University, Thailand

4. Time-Saver standards for Landscape Architecture, Chales W.Harris & Nicholas T.Dines

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