GEOMETRIK JALAN - Coordination Horizontal and Vertical Alignment

7/23/2019 GEOMETRIK JALAN - Coordination Horizontal and Vertical Alignment

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Vertical Horizontal Alignment

http://www.fhwa.dot.gov/environment/flex/ch05.htm(Chapter 5 from FHWAs Flexibility in Highway Design)
http://www.fhwa.dot.gov/environment/flex/ch05.htmhttp://www.fhwa.dot.gov/environment/flex/ch05.htmhttp://www.fhwa.dot.gov/environment/flex/ch05.htm


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Coordination of Horizontal and Vertical

Alignment

Source: FHWA, Chapter 5hra 2013 coordination


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Coordination of horizontal and

vertical alignment should begin

with preliminary design

Easier to make adjustments atthis stage

Designer should study long,

continuous stretches of

highway in both plan andprofile and visualize the whole

in three dimensions

(FHWA, Chapter 5)

Coordination of Horizontal and Vertical

Alignment

hra 2013 coordination


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Coordination of Vertical and Horizontal Alignment

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Lengkung dan kemiringan harusmemenuhi keseimbangan

Avoid

Excessive curvature to achieve flat grades

Excessive grades to achieve flat curvature

Lengkung Vertical harus dikoordinasikandengan horizontal

Lengkung horizontal tajam tidakdisarankan pada atau dekat puncak dari

lengkung cembung vertical Disarankan pengemudi tidak menerima

perubahan lengkung horizontalkhususnya malam hari.



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Coordination of Vertical and Horizontal Alignment5

Lengkung tajam horizontal disarankan tidak digunakan didaerah dekatlengkung cekung kemiringan tajam mendekati titik penggunaanlengkung cekung

Horizontal curves appear distorted

Vehicle speeds (esp. trucks) are highest at the bottom of a sag vertical

curve

Can result in erratic motion

Pada jalan dua lajur dan menyiap diizinkan, perlu dipertimbangkanruang lajur boleh menyiap.

Difficult to accommodate with certain arrangements of horizontal andvertical curvature

Need long tangent sections to assure sufficient passing sight distance



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Coordination of Vertical and Horizontal Alignment

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Pada areal persimpangan yang membutuhkan jarak pandang cukup,baik lengkung horizontal and vertical harus sedatar mungkin

Di areal pemukiman, alinemen diupayakan seminim mungkingangguannya terhadap lingkungan

Depressed highways are less visible Depressed highways produce less noise

Horizontal alignments can increase the buffer zone between roadway and cluster ofhomes

Bila dimungkinkan alinemen disarankan menghasilkan pemandangan

alam sebaik mungkin, baik lingkungan alamiah maupun buatan Highway should lead into not away from outstanding views Fall towards features of interest at low elevation Rise towards features best seen from below or in silhouette against the sky



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Coordination of Horizontal and Vertical Alignment

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Harus konsisten dengan topography

Persiapkan pengembangan properti di sepanjang rute jalan

Pertimbangkan nilai nilai komunitas

Sesuaikan dengan kontur asli dan kondisi lahan



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Tidak berpengaruh terhadapaesthetic, pemandangan,historis, dan sumberdayabudaya di sepanjang rute jalan

Menghasilkan pemandanganalam menarik

Rivers

Rock formations

Parks

Historic sites Outstanding buildings

Good Coordination of Horizontal and Vertical Alignment

Source: FHWA, Chapter 5hra 2013 coordination


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PLAN

PROFILE

Profile with tangent alignment

Avoid designing little local dips in an otherwise long, uniform grade. These

dips usually result from a desire to balance cut and fill and to reduce overhaul

Preferred

Tangent alignment



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PLAN

PROFILE

Profile with curve alignment

Short humps in the grade should be avoided

Preferred



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Short tangent on a crest between two horizontal curves

PLAN

PROFILE

This combination is deficient for two reasons.

The tangent between the curves is too short, and the reverse occurs on a crest



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PLAN

PROFILE

Short tangent on a crest between two horizontal curves

This combination is deficient for two reasons. The tangent between the curves is

to short, and the reverse occurs on a crest



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PROFILE

PLAN

Bumps

Preferred

A distant side view of a long grade on tangent will reveal every bumps

on it

Distant view showing bumps in profile gradeline


Line sight across open bottom lands


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Maybe we want this if we are trying to slow people down???

PROFILE

PLAN

Sharp angle appearence

This combination presents a poor appearance the horizontal curve looks

like a sharp angle



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Crest

PLAN

Coinciding curves in horizontal and vertical dimensions

When horizontal and vertical curves coincide, a very satisfactory

appearance results

PROFILE



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PLAN

Opposing curves in horizontal and vertical dimensions

When horizontal and vertical curve oppose, a very satisfactoryappearance results

PROFILE

SAG



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Horizontal alignment with small central angles

Very long fleet curves, even where not required by a design speed and regardless of profile,

also have a pleasing appearance when the central angle is very small

Minimum curve for the design

speed

Desirable curve for appearance

PLAN



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Coinciding vertices in horizontal and vertical dimensions

The classic case of coordination between horizontal and vertical alignment in which

the vertices of horizontal and vertical curves coincide, creating a rich effect of three -

dimensional S curves composed of convex and concave

PROFILE

PLAN



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Coinciding vertices with single phase skip

A legitimate case of coordination: one phase is skipped in the horizontal plane,

but vertices still coincide. The long tangent in plan is softened by vertical

curvature

Plan

Profile



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Koordinasi lemah alinemen horizontal dan vertikal

Profile

PLAN



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A

B

PLAN

Horizontal alignment should be balanced

The upper line is an example of poor design because the alignment consists of a long tangent

with short curves, whereas the balance between the curves and tangents in the lower

alignment is the preferred design



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PROFILE

PLAN

Line of sight

Perspective

A disjointed effect occurs when the beginning of a horizontal curve is

hidden from the driver by an intervening crest while the continuation

of the curve is visible in the distance beyond the intervening crest

Disjointed effect



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PROFILE

PLAN

Horizontal alignment view 2 breaks maximum

Vertical alignment view 3 breaks maximum

Good coordination of horizontal and vertical alignment

View

View



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Akhir sesi

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GEOMETRIK JALAN - Coordination Horizontal and Vertical Alignment

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