1. Parameter Material Embung Brami

Analisa Stabilitas Berbagai Kondisi Menggunakan Geo Studio Slope/W 2007

Tabel 1.1 Faktor aman minimum untuk bendungan urugan (Lambe dan Itman.1969 dan Sherad et al., 1963)

Faktor Aman

Minimum1 Akhir pelaksanaan 1,3* Lereng hulu dan hilir2 Penurunan air cepat (sudden drowdown) 1,0* Hanya lereng hulu

dari kondisi air penuh3 Penurunan air cepat (sudden drowdown) 1,2** Hanya lereng hulu

dari puncak bendungan elak (spill way)

4 Muka air parsial saat rembesan tetap 1,5 Hanya lereng hulu(steady seepage)

5 Rembesan tetap dengan muka air 1,5 Lereng hilirmaksimum

6 Gempa bumi (kasus 1,4,5 dengan 1,0 Lereng hulu dan hilirbeban gempa)

* Untuk tinggi timbunan 15 m atau pondasi relatif lunak gunakan fakto aman F = 1,4.** Faktor aman minimum harus 1,5 jika dalam hitungan stabilitas lereng kecepatan turunnya

air dan tekanan air pori ditentukan dari jaring arus (flow net)

KeteranganKondisi Perancangan

(Sumber: Cristady Hardiyatmo, Hary, 2007: 371)

A. Tanpa Gempa

MaterialUnit Weight Cohession Phi

(kN/m³) (kPa) (⁰)

Timbunan Inti 18.67 0.71 26.28

Timbunan Random 17.64 0.72 25.11

Filter 17.24 0.52 32.00

Rip-rap 22.00 0.00 32.00

Breksi/Pondasi 25.50 0.00 25.60

1. Kondisi Kosong Sesaat Setelah Kontruksi

1.504

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop 1.504

1.503

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu 1.503

1.500

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary 1.500

1.500

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgensertn-Price 1.500

1.578

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Bishop 1.578

1.500

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Janbu 1.500

1.512

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Ordinary 1.512

1.577

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Morgenstern-Price 1.577

2. Kondisi TMA +40 m

1.502

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop 1.502

1.528

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu 1.528

1.506

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary 1.506

1.503

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgensertn-Price 1.503

3. Kondisi TMA +34 m

1.712

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop 1.712

1.507

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu 1.507

1.503

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary 1.503

1.714

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgenstern-Price 1.714

4. Rapid Drawdown

1.510

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop RDD 1.510 (day 15)

1.568

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu RDD 1.568 (day 15)

1.501

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary RDD 1.501 (day 15)

1.509

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgenstern-Price RDD 1.509 (day 15)

B. Dengan Gempa (kh=0,12)

1. Kondisi Kosong Sesaat Setelah Kontruksi

1.202

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop gempa 1.202

1.234

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu gempa 1.234

1.250

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary gempa 1.250

1.215

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgenstern-Price gempa 1.215

1.204

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Bishop gempa 1.204

1.202

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Janbu gempa 1.202

1.207

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Ele

vasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Ordinary gempa 1.207

1.202

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

u/s Morgenstern-price gempa 1.202

2. TMA + 40 m

1.206

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop gempa 1.206

1.204

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu gempa 1.204

1.205

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary gempa 1.205

1.203

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgenstern-Price gempa 1.203

3. TMA + 30 m1.301

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Bishop gempa 1.301

1.211

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Janbu gempa 1.211

1.200

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70

Elevasi (m

)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Ordinary gempa 1.200

1.315

AS DAM

M.A.N +40.00 m

M.A.M +34.00 m

Jarak (m)

0 1 2 3 4 5 6 7 8 910 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70E

levasi (m)

23

25

27

29

31

33

35

37

39

41

43

45

d/s Morgenstern-price gempa 1.315

C. Rekapitulasi Angka Keamanan Stabilitas Lereng Embung Brami

Dari Analisa Stabilitas lereng Embung Brami dengan Geo Studio 2007 (Slope/W Analysis

Metode Grid And Radius) dari semua kondisi yang telah dianalisa didapatkan hasil angka

keamanan konstruksi embung dalam kondisi AMAN (memenuhi syarat minimum yang

tertera pada Tabel 1.1) dimana hasil rekapitulasi angka keamanan sebagai berikut.

Tanpa Gempa u/s d/s u/s d/s u/s d/s u/s d/sKosong 1.578 1.504 1.514 1.503 1.512 1.500 1.577 1.500Isi TMA + 40 m - 1.502 - 1.528 - 1.506 - 1.503Isi TMA + 34 m - 1.712 - 1.507 - 1.503 - 1.714Rapid drawdown - 1.510 - 1.568 - 1.501 - 1.509Gempa ( k=0.12) u/s d/s u/s d/s u/s d/s u/s d/sKosong 1.204 1.202 1.202 1.234 1.207 1.250 1.202 1.215Isi TMA + 40 m - 1.206 - 1.204 - 1.205 - 1.203Isi TMA + 34 m - 1.301 - 1.211 - 1.200 - 1.315

Kondisi PembebananBishop Janbu Ordinary Morgenstern

Metode Analisis