presentasi mektan bab iii

PEMAMPATAN TANAH

(9)

PEMAMPATAN TANAH

(9)

PEMADATAN (4)

PEMADATAN (4)

DISTRIBUSI TEGANGAN

(8)

TEGANGAN EFEKTIF

(7)

KLASIFIKASI TANAH

(3)

REMBESAN AIR DALAM TANAH

(5)

REMBESAN AIR DALAM TANAH

(5)

BAGAN ALIR BAHASANBAGAN ALIR BAHASAN

GAYA ANGKAT DIBAWAH

BANGUNAN AIR (6)

KOMPOSISI TANAH

(2)

TANAH (1)

POKOK BAHASAN POKOK

BAHASAN

A. UmumB. Tujuan

Klasifikasi Tanah

C. Jenis Pengujian Tanah1. Analisa Ayakan2. Analisa

Hidrometer3. Kurva Distribusi

D. Sistim Klasifikasi Tanah

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

POKOK BAHASAN POKOK

BAHASAN

A. UmumB. Tujuan

Klasifikasi Tanah




1. WHY DO WE NEED TO CLASSIFY SOILS ???????To describe various soil types encountered in thenature in a systematic way and gathering soils thathave distinct physical properties in groups and units.2. GENERAL REQUIREMENTS OF A SOILCLASSIFICATION SYSTEM:a- Based on a scientific methodb- Simplec- Permit classification by visual and manual tests.d- Describe certain engineering propertiese- Should be accepted to all engineers.

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

POKOK BAHASAN POKOK

BAHASAN

A. UmumB. Tujuan

Klasifikasi Tanah




3. VARIOUS SOIL CLASSIFICATION SYSTEMS:a- Geologic Soil Classification Systemb- Agronomic Soil Classification Systemc- Textural Soil Classification System (USDA)d- American Association of State Highway

Transportation Officials System (AASHTO)e- Unified Soil Classification System (USCS)f- American Society for Testing and Materials

System (ASTM)g- Federal Aviation Agency System (FAA)

POKOK BAHASAN POKOK

BAHASAN

A. UmumB. Tujuan

Klasifikasi Tanah




BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

1.

KLASIFIKSAI TANAH DIDASARKAN PADA :-

PLASTISITAS TANAH-

UKURAN BUTIRAN.

2.

TUJUAN KLASIFIKASI TANAH :-

MENGELOMPOKKAN TANAH YANG BERBEDA-BEDA TAPIMEMPUNYAI SIFAT SERUPA KEDALAM GROUP-GROUPDAN SUB GROUP UNTUK : MENDAPATKAN GAMBARANUMUM MENGENAI PERILAKU SUATU TANAH.

3.

JENIS TEST UNTUK MENDAPATKAN UKURAN BUTIRAN :-

ANALISA/TEST AYAKAN (GAMBAR 1).-

ANALISA/TEST HYDROMETER (GAMBAR 2)

4.

ANALISA AYAKAN :-

AYAKAN YANG DIKAPAI : AYAKAN US-STANDARD.-

UKURAN LUBANG AYAKAN.

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

POKOK BAHASAN POKOK

BAHASAN

A. UmumB. Tujuan

Klasifikasi Tanah




NO. AYAKAN DIAMETER LUBANG AYAKAN (mm)

4 4.756 3.358 2.3610 2.0020 0.8530 0.6040 0.42550 0.3060 0.2580 0.18100 0.15140 0.106170 0.088200 0.075

POKOK BAHASAN POKOK

BAHASAN

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




5. ANALISA HYDROMETER

DASAR : PRINSIP SEDIMENTASI DARI BUTIRAN TANAH DIDALAM AIR

FAKTOR-FAKTOR YANG MEMPENGARUHI KECEPATAN MENGENDAP :

BENTUK, UKURAN, BERAT BUTIRAN TANAH

POKOK BAHASAN POKOK

BAHASAN

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




0 .0 0 0 1 0 .0 0 1 0 .0 1 0 .1 1 1 0 1 0 00

2 0

4 0

6 0

8 0

1 0 0

P a r tic le s ize (mm)

% F

iner

W

Well graded

Grading curves

0 .0 0 0 1 0 .0 0 1 0 .0 1 0 .1 1 1 0 1 0 00

2 0

4 0

6 0

8 0

1 0 0


% F

iner

W

Well graded

U

Uniform

Grading curves

Grading curves

0 .0 0 0 1 0 .0 0 1 0 .0 1 0 .1 1 1 0 1 0 00

2 0

4 0

6 0

8 0

1 0 0


% F

iner

W

Well graded

U

Uniform

P

Poorly graded

Grading curves

0 .0 0 0 1 0 .0 0 1 0 .0 1 0 .1 1 1 0 1 0 00

2 0

4 0

6 0

8 0

1 0 0


% F

iner

W

Well graded

U

Uniform

P

Poorly graded

C

Well graded with some clay

Grading curves

0 .0 0 0 1 0 .0 0 1 0 .0 1 0 .1 1 1 0 1 0 00

2 0

4 0

6 0

8 0

1 0 0


% F

iner

W

Well graded

U

Uniform

P

Poorly graded

C

Well graded with some clay

F

Well graded with an excess of fines

D10 : Maximum size of the smallest 10%D30 : Maximum size of the smallest 30%D50 : Maximum size of the smallest 50% D60 : Maximum size of the smallest 60%D10: Effective size (eg for permeability)

Cu : Coefficient of Uniformity = D60 /D10Cc : Coefficient of Curvature = (D30 )2/(D60 –D10 ) (also called Cg : Coefficient of GradationPermeability, k= Ck (D10)2 cm/sec

(Hazen)

5.

ANALISA HYDROMETERDASAR :

PRINSIP SEDIMENTASI DARI BUTIRAN TANAHDIDALAM AIR.

FAKTOR-FAKTOR YANG MEMPENGARUHI KECEPATAN MENGENDAP : BENTUK, UKURAN, BERAT BUTIRAN TANAH.

6.

KURVA DISTRIBUSI UKURAN BUTIRAN (GRAIN SIZE DISTRIBUTION) ADA 3 (TIGA) KELOMPOK BENTUK GRAFIK :

-

GAP GRADED (CURVA A) :TANAH DIMANA 1 ATAU LEBIH UKURAN BUTIR TIDAKADA.

-

WELL GRADED (CURVA B) :TANAH DIMANA UKURAN BUTIRANNYA TERBAGIMERATA DALAM SUATU BATASAN YANG LUAS.

-

UNIFORM GRADED (CURVA C) :TANAH YANG UKURAN BUTIRANNYA HAMPIR SAMA.

Uscs

Sistem klasifikasi yang di pakai :

1. USCS ( Unified Soil Classification System)2. AASHTO ( American Association of State

Highway and Transportation Officials)

1. Persamaan2. Perbedaan

Persamaan

Persamaan :

1.Kedua

system tsb. didasarkan

pada ukuran

butir

dan

plastisitas

tanah

2.Kedua

system memisahkan

tanah kedalam

2 kategori

:

-

tanah

berbutir

kasar

( coarse grained)-

tanah

berbutir

halus

( fine grained)

Laboratory CriteMajor Divisions Group

Symbol Typical Names Fines (%) Grading

Cu > 4 GW

Well-graded gravels and gravel-sand mixtures, little or no fines 0-5 1 < Cc < 3 Clean

Gravels GP

Poorly graded gravels and gravel-sand mixtures, little or no fines

0-5 Not satisfying GW

requirements

GM Silty gravels, gravel-sand-silt mixtures >12 Be

Gravels

50% or more of course

fraction retained on

the 4.75 mm (No. 4) sieve Gravels

with Fines GC Clayey gravels, gravel-sand-clay mixtures >12 Ab

Cu > 6 SW

Well-graded sands and gravelly sands, little or no fines 0-5 1 < Cc < 3 Clean

Sands SP

Poorly graded sands and gravelly sands, little or no fines

0-5 Not satisfying SW requirements

SM Silty sands, sand-silt mixtures >12 Be

Course-Grained Soils

More than 50%

retained on the 0.075

mm (No. 200) sieve

Sands

50% or more of course

fraction passes the 4.75

(No. 4) sieve Sands with Fines SC Clayey sands, sand-clay

mixtures >12 A

Inorganic silts, very fine

1. USCS ( Unified Soil Classification System)

ML Inorganic silts, very fine sands, rock four, silty or clayey fine sands

Use plasticity chart

CL Inorganic clays of low to medium plasticity, gravelly/sandy/silty/lean clays

Use plasticity chart Silts and Clays

Liquid Limit 50% or less

OL Organic silts and organic silty clays of low plasticity Use plasticity chart

MH Inorganic silts, micaceous or diatomaceous fine sands or silts, elastic silts

Use plasticity chart

CH Inorganic clays or high plasticity, fat clays Use plasticity chart

Fine-Grained Soils

More than 50%

passes the 0.075 mm

(No. 200) sieve Silts and Clays

Liquid Limit greater than 50%

OH Organic clays of medium to high plasticity Use plasticity chart

Highly Organic Soils Pt Peat, muck, and other highly organic soils

PerbedaanAyakan yang dipakai untuk memisahkan pasir dan kerikil

ayakan no. 10 ayakan no. 4

Perbedaan tanah-tanah gravelly dan sandy soil

Tidak diberikan Dibedakan secara jelas

Klasifikasi untuk tanah organik Tidak diberikan OL,OH dan Pt

( Gambut)

yg lewat ayakan no. 200 < 35%

yg lewat ayakan no. 200 < 50%

Tanah dikatakan berbutir kasar apabila

Uraian Perbedaan AASHTO USCS

2. Perbedaan

Klasifikasi Tanah menggunakan 2 simbol huruf:

Huruf pertama menggambarkan komponen utama dari tanah, terdiri dari :

1)

coarse grained soils (gravel(G) and sand(S));2)

fine grained soils (silt(M) and clay(C));3)

organic soils (O); and4)

Peat (Pt).

Huruf kedua menggambarkan hubungan tanah dgn :

1)

whether a coarse-grained soil is Well(W) or poorly(P) graded;2)

whether a coarse-grained soil contains appreciable silt(M) or clay(C); and

3)

whether a fine-grained soil plasticity is high(H) or low(L).

KLASIFIKASI USCS (Unified Soil Classification System)

Run sieve analysis

< 50% pass #200

> 50% of coarse fraction retained

on #4

< 50% of coarse fraction retained

on #4

Gravel Sand

> 50% pass #200

Use plasticity chart (Fig. 3.14)

Silt, organic, or clay

Persamaan garis A : PI = 0.73 (LL – 20)

G

<5% pass #200 5-12% pass #200 > 12 % pass #200

G W

G P

GW-GC

GW-GM

GP-GC

GP-GM

GC

GM

GC-GM

Use gradation curve to designate


Use gradation curve and plasticity chart

to designate

Cu> 4 and 1 < Cc < 3 GW Well graded gravelCu< 4 and 1 >Cc > 3 GP Poorly graded gravel

Cu> 4 and 1 < Cc < 3 and fines classify as CL or CH

GW - GC Well graded gravel with clay

Cu> 4 and 1 < Cc < 3 and fines classify as ML or MH

GW - GM Well graded gravel with silt

Cu< 4 and 1 >Cc > 3 and fines classify as CL or CH

GP - GC Poorly graded gravel with clay

Cu< 4 and 1 >Cc > 3 and fines classify as ML or MH

GP - GM Poorly graded gravel with silt

Fines classify as CL or CH ( LL and PL above A-line)

GCClayey gravel

Fines classify as ML or MH ( LL and PL below A-line)

GMSilty gravel

Fines classify as CL - ML ( LL and PL in shaded area)

GC - GMSilty, clayey gravel

Run sieve analyasis and if less than 50% passed the #200 sieve, then the soil is coarse. If more than 50% of the coarse material is retained on the #4 sieve, then the soil is gravel.% passing #200 sieve

Unified Soil Classification Criteria Group Symbol Group Name

Less than 5%

Between 5 % & 12%

More than 12%

Gravel/Kerikil

7. TIGA PARAMETER DAPAT DITENTUKAN DARI KURVA GRAIN SIZE DISTRIBUTION :

-

UKURAN EFEKTIF (EFFECTIVE SIZE)D10 :

DIAMETER BUTIRAN DIMANA 10% DARITOTAL BUTIRAN LOLOS/LEBIH KECILDARI DIAMETER TERSEBUT.

-

KOEFISIEN KESERAGAMAN (UNIFORMITY COEF.) = Cu .

-

KOEFISIEN GRADASI (GRADATION COEF.) = Cc .10

60

DDCu

1060

230

DxDDCc

D30 = DIAMETER BUTIRAN DIMANA 30% DARI TOTAL BUTIRAN LOLOS/LEBIH KECIL DARI DIAMETER TERSEBUT

D60 = IDEM, 60% < DIAMETER TERSEBUT

S

<5% pass #200 5-12% pass #200 > 12 % pass #200

SW

SP

SW-SCSW-SMSP-SCSP-SM

SC

SM

SC-SM



Use gradation curve and plasticity chart

to designate

Cu> 6 and 1 < Cc < 3 SW Well graded sandCu< 6 and 1 >Cc > 3 SP Poorly graded sand

Cu> 6 and 1 < Cc < 3 and fines classify as CL or CH

SW - SC Well graded sand with clay

Cu> 6 and 1 < Cc < 3 and fines classify as ML or MH

SW - SM Well graded sand with silt

Cu< 6 and 1 >Cc > 3 and fines classify as CL or CH

SP - SC Poorly graded sand with clay

Cu< 6 and 1 >Cc > 3 and fines classify as ML or MH

SP - SM Poorly graded sand with silt

Fines classify as CL or CH ( LL and PL above A-line)

SCClayey sand

Fines classify as ML or MH ( LL and PL below A-line)

SMSilty sand

Fines classify as CL - ML ( LL and PL in shaded area)

SC - SMSilty, clayey sand

Group Symbol Group Name

Less than 5%

Between 5 % & 12%

More than 12%

Run sieve analyasis and if less than 50% passed the #200 sieve, then the soil is coarse. If less than 50% of the coarse material is retained on the #4 sieve, then the soil is sand% passing #200 sieve

Unified Soil Classification Criteria

Sand/Pasir

Silt, organic, or clay

LL<50%

LLR<0.75 LLR>0.75

LL and PI plot below

A-line

LL and PI plot in

shaded area

LL and PI plot above

A-line

LL>50%

LLR<0.75 LLR>0.75

LL and PI plot below

A-line

LL and PI plot above

A-line

OL ML CL-ML CL OH MH CH

SILT OR CLAY

LLR < 0.75 OL Organic silt or clayLLR > 0.75 and PI < 4 or plots below A-line in Fig. ML Inorganic siltLLR > 0.75 and PI > 7 or plots above A-line in Fig. CL Lean clayLLR > 0.75 and PI > 7 and LL and PI in shaded area of Fig. CL-ML Silty clay

LLR < 0.75 OH Organic silt or clayLLR > 0.75 and PI plots below A-line in Fig. MH Elastic siltLLR > 0.75 and PI plots on or above A-line in Fig. CH Fat clay

More than 50%

Run sieve analyasis and if less than 50% passed the #200 sieve, then the soil is fine.Run liquid limit and plastic limit tests on materials passing #40 sieve. Note that ASTM requires that the liquid limit be determined using oven dried and undried samples . The ratio of the dried to the undried value is called the liquid limit ratio LLR.

Less than 50%

Liquid Limit Unified Soil Classification Criteria Group Symbol Group Name

PEAT

Highly organic soils. Normally more than 20% by weight is organic

Primary organic matter, dark in color and organic odor Pt Peat

14.

KUALITAS TANAH SUB-GRADE SEBANDING DENGAN KEBALIKAN DARI HARGA GI

15. CATATAN :•

LLR = LIQUID LIMIT RATIO

•

PEAT = TANAH GAMBUT= TANAH ORGANIK DENGAN KANDUNGAN

ORGANIK ≥

75%.

NATURALTANAHLLHARGADIOVENYANGTANAHLLHARGALLR

•

GROUP OL dan

OH :

•

LANAU ORGANIK atau•

LEMPUNG ORGANIK•

PLASTISITAS RENDAH UNTUK OL (SEPERTI ML)•

PLASTISITAS TINGGI UNTUK OH (SEPERTI MH) PERILAKUNYA DITENTUKAN OLEH KANDUNGAN

ORGANIK

•

Pt = Peat = TANAH DENGAN KANDUNGAN ORGANIK TINGGI:

•

PEAT.= Tanah

GAMBUT•

HUMUS dan

Bahan

Organik

yang telah

membusuk/terurai•

TANAH RAWA

DAYA DUKUNG RENDAHKEMAMPUMAMPATAN TINGGI

LL= 33

PI= 12PI= 0.73(LL-20), A-line

PI=0.73(33-20)=9.49

SC (15% gravel)

Clayey sand with gravel

(Santamarina

et al., 2001)

Passing No.200 sieve 30 %Passing No.4 sieve 70 %

LL= 33

PI= 12

Highly

Example

A-1 (well graded)

A-7-5 IP <

(LL-30)

A-7-6 IP > (LL-30)

CLASSIFICATIO N O F HIG HW AY SUBG RADE M ATERIALS(W ith suggested subgroups)

G eneral C lassification

G roup C lassification

Sieve Analysis,Percent Passing:

No. 10No. 40

No. 200

Characteristics offraction passing # 40:

Liquid Lim itP lastic ity Index

G roup Index

Usual Types of S ignific icant Constituent

M aterials

G eneral Rating as Subgrade

A-2

A-1-a A-1-b A-2-4 A-2-5 A-2-6 A-2-7

0-60

Stone Fragm ents, G ravel and Sand

A-3

51-1000-10

N.P.0

Fine Sand

0-50

G ranular M aterials (35% or less passing No. 200)

0-35 0-35 0-35 0-350-300-15

0-500-25

A-1

0-100-40 41+

0-100-4011+

41+11+

0 0-4

Silty or C layey G ravel and Sand

Excellent to G ood

Silt-C lay M aterials (M ore than 35% passing #200)

A-4 A-5 A-6A-7

A-7-5A-7-6

36-100 36-100 36-100 36-100

0-400-10

41+0-10

0-4011+

41+11+

Silty Soils C layey Soils

Fair to Poor

0-8 0-12 0-16 0-20

Dominan

kerikilDominan

pasir Lanau

dgn

plastisitas

Lanau

dgn

plastisitas

Lempung

dgn

plastisitas

Lempung

dgn

plastisitas

AASHTO SOIL CLASSIFICATIONAASHTO ( American Association of State Highway and Transportation Officials)

REVIEW JENIS TANAH UNTUK SOIL-CEMENT DAN CEMENT-MODIFIED SOIL

AASHTO Classification of Soils

General classification

Granular Materials (35 % or less passing No. 200)

Silt-Clay Materials (more than 35 % passing No. 200

Group A-1 A-3 A2 A-4 A-5 A-6 A-7 classification A-1-a A-1-b A-2-4 A-2-5 A-2-6 A-2-7 A-7-5, A-7-6 Sieve analysis, Percent passing : No. 10 50 max - - - - - - - - - - No. 40 30 max 30 max 30 max - - - - - - - - No. 200 15 max 15 max 15 max 35 max 15 max 15 max 15 max 36 min 36 min 36 min 36 min Characteristics of fraction passing No. 40 : Liquid limit - - 40 max 40 min 40 max 41 min 40 max 41 min 40 max 41 min Plasticity index 6 max N.P. 10 max 10 max 11 min 11 min 10 max 10 max 11 min 11 min*) Usual types of significant stone fragments fine silty or clayey gravel and sand silty soils clayey soils constituent gravel and sand sand materials General rating as excellent to good fair to poor subgrade * ) Plasticity index of A-7-5 is equal to or less than L.L. minus 30. Plasticity index of A-7-6 subgroup is greater L.L. minus 30.

Run sieveanalysis

≤

35% pass #200 implies granular

> 36% pass #200 implies silt-clay

<25%#200

≤

35% pass #200

Run LL and PL on material passing # 40


<50%Pass #40

>51%Pass #40

<15% pass #200<30% pass # 40<50% pass #10PI is less than 6

<25% pass #200<50% pass # 40PI is less than 6

A-1-a

A-1-b


PI<10

PI>11

<10% pass #200 A-3

LL<40

LL>41

LL<40

LL>41

A-2-4

A-2-5

A-2-6

A-2-7

PI<10

PI>11

LL<40

LL>41

LL<40

LL>41

A-4

A-5

A-6

PI ≤

LL-30 or PL ≥

30

PI > LL-30 or PL < 30

A-7-5

A-7-6

Figure 3.20. Flow chart showing the AASHTO classification system

ExamplePassing No.200 86%LL=70, PI=32LL-30=40 > PI=32

3347.33)10PI)(15F(01.0

)40LL(005.02.0)35F(GI

200

200

Round off A-7-5(33)

Passing No.200 86%LL=70, PI=32LL-30=40 > PI=32

POKOK BAHASAN POKOK

BAHASAN

b. BATAS CAIR ( LIQUID LIMIT = LL)LL = kadar

air tanah

dimana

apabila

dibuat

goresan

pada

tanah

tersebut

dengan

spatula standard akan

menutup

pada

25 kali pukulan.

Apparatus and grooving tool

Groove cut in sample prior to the test

Groove closed over 12.5 mm – soil at wL if this requires 25 “blows”

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




POKOK BAHASAN POKOK

BAHASAN

c. BATAS PLASTIS ( PLASTIC LIMIT = PL)PL = Kadar

air tanah

dimana

apabila

tanah

tersebut

digulung

sampai

dengan

diameter 3.2 mm mulai

terjadi

retak-retak.

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




POKOK BAHASAN POKOK

BAHASANd. INDEKS PLASTIS (PLASTICITY INDEX = IP)

PI = IP = LL - PL

LLPLSLSOLID SEMI SOLID PLASTIS CAIR

0

LI 0 1

e. INDEKS KECAIRAN (LIQUIDITY INDEX= LI)

0 < LI < 1 Tanah

berada

dalam

daerah

plastisLI > 1 Tanah

dalam

keadaan

cair/hampir

cair

IPPLwLI C

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




POKOK BAHASAN POKOK

BAHASAN

1. STRUKTUR TANAH :- Susunan geometrik partikel tanah

- Gaya antar partikel

2. TANAH BERBUTIR KASAR ( GRANULAR SOIL)

Gaya antar partikel sangat kecil

diabaikan , jadi : struktur tanah = susunan geometrik partikel

3. TANAH BERBUTIR HALUS YANG KOHESIVE (COHESIVE SOIL; MIS. LEMPUNG)

Gaya antar partikel

sangat dominan

Jadi : struktur tanah kohesive = susunan geometrik partikel tanah + gaya antar partikel

C. STRUKTUR TANAH

BAB IIIKLASIFIKASI

TANAH

BAB IIIKLASIFIKASI

TANAH

A. UmumB. Tujuan

Klasifikasi Tanah




presentasi mektan bab iii

Documents