Ferry R., Ir., MT. (412153067)

TS Unjani

SUPERELEVASI

1) Superelevasi adalah suatu kemiringan

melintang di tikungan yang berfungsi

mengimbangi gaya sentrifugal yang

diterima kendaraan pada saat berjalan

melalui tikungan pada kecepatan VR.

2) Nilai superelevasi maksimum ditetapkan

4% – 10 %.

Ferry R., Ir., MT. (412153067)

TS Unjani

Ferry R., Ir., MT. (412153067)

TS Unjani

GAYA SENTRIFUGAL DI TIKUNGAN

• Dengan adanya lintasan yg berbentuk lingkaran (Rc), maka kendaraan yg melintas akan mendapatkan gaya sentrifugal; arahnya keluar lingkaran.

• Gaya sentrifugal ini akan diimbangi oleh gesekan samping antara ban kendaraan dan permukaan jalan (f) dan kemiringan melintang permukaan jalan / superelevasi (e).

fe

VR

127

2

Hubungan R, V, e, dan f

Ferry R., Ir., MT. (412153067)

TS Unjani

R

R

V

g

W 2

feg

VR

gR

Vfe

gR

VffWfNF

R

V

g

WFW

2

2

2

2

tancos

cossin

Ferry R., Ir., MT. (412153067)

TS Unjani

JARI-JARI TIKUNGAN

(1) Jari - jari tikungan minimum (Rmin) ditetapkan sebagaiberikut:

di mana :

Rmin = Jari jari tikungan minimum (m),

VR = Kecepatan Rencana (km/j),

emax = Superelevasi maksimum (%),

f max = Koefisien gesek maksimum

(2) Terdapat Tabel untuk menetapkan Rmin

maxmax

2

min127 fe

VR R

Ferry R., Ir., MT. (412153067)

TS Unjani

Tabel Panjang Jari-jari Minimum

Faktor Gesekan Samping (f)Harga f tergantung pada kecepatan rencana; dng memper-

timbangkan curah hujan di Indonesia, harga f diambil sbb:

V km/jam 120 100 80 60 50 ≤40

f 0.10 0.11 0.12 0.13 0.14 0.15

Sumber : TATA CARA PERENCANAAN GEOMETRIK JALAN ANTAR KOTA No. 038/TBM/1997

Sumber : TATA CARA PERENCANAAN GEOMETRIK JALAN ANTAR KOTA No. 038/TBM/1997

Ferry R., Ir., MT. (412153067)

TS Unjani

ASUMSI f untuk DESIGN

Sumber : a Policy on GEOMETRIC DESIGN on Highways and Streets 2011 (6th ed)

Ferry R., Ir., MT. (412153067)

TS Unjani

METODE DISTRIBUSI e dan f

Sumber : a Policy on GEOMETRIC DESIGN on Highways and Streets 2011 (6th ed)

• Method 1—Superelevation and side friction are

directly proportional to the inverse of the radius

(i.e., a straight-line relation exists between 1/R =

0 and 1/R = 1/Rmin).

• Method 2—Side friction is such that a vehicle

traveling at design speed has all lateral

acceleration sustained by side friction on curves

up to those designed for fmax. For sharper curves,

f remains equal to fmax and superelevation is then

used to sustain lateral acceleration until e reaches

emax. In this method, first f and then e are

increased in inverse proportion to the radius of

curvature.

• Method 3—Superelevation is such that a vehicle

traveling at the design speed has all lateral

acceleration sustained by superelevation on

curves up to those designed for emax. For sharper

curves, e remains at emax and side friction is then

used to sustain lateral acceleration until f reaches

fmax. In this method, fi rst e and then f are

increased in inverse proportion to the radius of

curvature.

• Method 4—This method is the same as Method

3, except that it is based on average running speed

instead of design speed.

• Method 5—Superelevation and side friction are

in a curvilinear relation with the inverse of the

radius of the curve, with values between those of

Methods 1 and 3.

Ferry R., Ir., MT. (412153067)

TS Unjani

AVERAGE RUNNING SPEED

Sumber : a Policy on GEOMETRIC DESIGN on Highways and Streets 2011 (6th ed)

Ferry R., Ir., MT. (412153067)

TS Unjani

METODE PENCAPAIAN SUPERELEVASI

TIKUNGAN S-C-S

Sumber : TATA CARA PERENCANAAN GEOMETRIK JALAN ANTAR KOTA No. 038/TBM/1997

Ferry R., Ir., MT. (412153067)

TS Unjani

TIKUNGAN FC

Sumber : TATA CARA PERENCANAAN GEOMETRIK JALAN ANTAR KOTA No. 038/TBM/1997

METODE PENCAPAIAN SUPERELEVASI