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PT. L&M Systems Indonesia Method Statement-Permanent Non Removable Ground Anchor

METHOD STATEMENT

PERMANENT NON REMOVABLE GROUND ANCHORPROYEK NORMALISASI KALI CILIWUNG

WASKITA – HUTAMA JORevision – 01

May 2014

L&M

PT. L&M SYSTEMS INDONESIAJL. JUANDA III No. 8

KEBON KELAPA GAMBIR, JAKARTA 10120TELP : 021 - 345 8568FAX : 021 - 345 4044

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TABLE OF CONTENT

1. GENERAL……………………………………………………..3

2. TENDON ASSEMBLY………………………………………..3

3. SEQUENCE OF INSTALLATION……………………………4

4. STRESSING……………………………………………………4

5. GROUT MIX PROPORTION………………………………….5

6. MATERIAL SPECIFICATION………………………………..6

7. QUALITY CONTROL…………………………………………6

8. RECORDING…………………………………………………..7

9. EQUIPMENT…………………………………………………..7

APPENDIX – A : SITE ORGANIZATION CHART

APPENDIX – B : LIST OF EQUIPMENT

APPENDIX – C : MATERIAL SPECIFICATION & BROCHURES

APPENDIX – D : INSPECTION TEST PLAN & FORMS

APPENDIX – E : ILLUSTRATION DRAWINGS

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METHOD STATEMENTPERMANENT NON REMOVABLE GROUND ANCHOR

I. GENERAL I. UMUMThis method statement is

prepared to state the proposed construction method for Permanent Non Removable Ground Anchor Work and shall be after approval is given by the engineer, distributed to all parties concerned so that the Ground Anchor Works work may be carried out with the same information.The ‘NORMALISASI KALI CILIWUNG’

Project requires a Permanent Non Removable Ground Anchor as a part of Sheet Pile structure to execute the river excavation.

This method statement describes the step by step sequential order of the operation entailed in :

1. Fabrication / Assembly2. Drilling, Installation and Grouting3. Stressing4. Remove / Releasing

II. TENDON ASSEMBLY AND CONFIGURATION

The effective strands shall comprise of 12.7 mm diameter uncoated 7-wire Low Relaxation PC Strand in compliance wiyh ASTM A-416 Grade 270 – Low Relaxation with minimum breaking strength of 183.7 kN (UTS).

As the system was Permanent Ground Anchor, the tendon’s configuration as follow :

1. They are fully greased and sheated with HDPE hose as specified

2. At end node of tendon detailed with looping 600 mm pitch 2 stagings 3 number of strands each loop.

3. To binding strands into tendons each 1.00 m pitch to be spaced plastic

spacer and centralizer in order to keep tendon cnter to drilling hole.

Metode Pelaksanaan ini disiapkan sebagai proporsal metode konstruksi untuk pekerjaan Permanent Non Removable Ground Anchor dan setelah disetujui oleh konsultan, didistribusikan kepada semua pihak yang terlibat agar pekerjaan Ground Anchor ini dapat dilaksanakan dengan informasi yang sama.

Proyek ‘NORMALISASI CILIWUNG’ ini memerlukan Permanent Non Removable Ground Anchor sebagai bagian dari strutur Sheet Pile untuk pelaksanaan normalisasi sungai.

Metode kerja ini menggambarkan langkah demi langkah urutan kerja sebagai berikut :

1. Fabrikasi2. Pengeboran, Pemasangan dan

Grouting.3. Penarikan 4. Pembongkaran.

II. PERAKITAN TENDON DAN KONFIGURASI

Strand yang dipakai adalah diameter 12.7 mm type uncoated 7-kabel sesuai standar ASTM A-416 Grade 270 – Low Relaxation dengan kekuatan putus minimal 183.7 kN (UTS).

Sesuai dengan sistem Permanent Ground Anchor konfigurasi tendon adalah sebagai berikut :

1. Seluruh permukaan PC Strand dilapisi gemuk dan dibungkus dengan pipa HDPE sebagaimana yang disyaratkan.

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2. Pada bagian ujung tendon diperinci dengan loop jarak masing-masing 600 mm tiap loop berjumlah 3 strand.

3. Pada jarak 1.00 m dipasang centralizer untuk meletakkan tendon di tengah lubang pengeboran.

III. SEQUENCE OF GROUND ANCHOR INSTALLATION

The Sequence of Ground Anchor Installation is described in detail below :

Drill to the design length of ground anchor and its inclination, plus an over drill of about 300 to 500 mm to allow for any heavy soil or rock materials that cannot be removed by flushing.

Upon completion of drilling, the drilled hole flushed with water and/or air for 2 or 3 minutes to remove as much heavy solids as possible.

The drill rods are then extracted.

A HDPE tremie hose is lowered to the bottom of the drilled hole and flush with the clean water.

The fabricated ground anchor tendon is then home into the drill hole.

Grouting is then carried out through the tremie hose. The hose is pulled up in stages during the grouting process but must be maintained at about 3.00 M below the theoretical grout level.

Grouting shall be terminated once about the same consistency as that in the mixer/ agitator appears at the surface.

Anchor plate or anchor bracket (vertical wall systems) is installed in accordance to design drawing.

IV. STRESSING OF GROUND ANCHOR

Stressing shall not commence until the grout had attained their 7 days strength or characteristic strength of 300 kg/cm2 cube test. Each anchor is stressed by a jack machine.

III. URUTAN PEMASANGAN GROUND ANCHOR

Urutan pemasangan ground anchor digambarkan secara detail berikut ini :

Pengeboran dilakukan dengan panjang dan kemiringan sesuai dengan desain dan dilebihkan sekitar 300 sampai 500 mm untuk tempat seandainya terdapat material yang tidak dapat dikeluarkan saat dilakukan pembersihan.

Setelah pengeboran selesai, lubang bekas pengeboran dibersihkan dengan air atau angin selama 2 atau 3 menit untuk mengeluarkan sebanyak mungkin sisa material.

Kemudian pipa pengeboran dapat dikeluarkan.

Pipa HDPE dapat dimasukkan ke dasar lubang dengan terlebih dahulu dicuci air sampai bersih.

Fabrikasi dari tendon ground anchor dimasukkan kedalam lubang pengeboran.

Kemudian dilanjutkan dengan pekerjaan grouting melalui pipa tremie. Dan pipa tremie ini ditarik secara bertahap selama grouting dan kemudian pipa dibiarkan / ditahan pada ketinggian 3.00 M dibawah batas teoritis grouting.

Adonan material grouting harus mempunyai konsistensi yang sama antara yang ada di pengaduk dengan hasil grouting yang keluar di permukaan.

Plat angkur atau braket ( untuk sistem dinding vertical ) dipasang sesuai dengan gambar desain.

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IV. PEKERJAAN STRESSING GROUND ANCHOR.

Stressing tidak akan dilakukan sampai kekuatan tekan umur grouting 7 hari atau sudah mencapai kekuatan karakteristik kubus 300 kg/cm2. Masing-masing angkur di stressing dengan menggunakan hidrolik jack.

The stressing jack pressure gauge shall

be used as a basis for the stressing loads.Measurement of strand elongation shall be by measure tape.

Every contract ground anchor shall be proofed stressed to 125 % design loads and locked off at 115 % of design load.

The stressing cycle is shown in Table 1 below :

TABLE 1 :ACCEPTANCE TEST LOAD CYCLE

V. GROUT MIX PROPORTION AND STRENGTH.

Water = 21 – 22.5 ltr

Cement = 50 kg Add. Tricosal = 500 grams W/C Ratio = 0.42 – 0.45 Strength 7 d = 30 N/mm2 Strength 28 d = 40 N/mm2

Catalogue of the non-shrink additive TRICOSAL 181 is attached.

Kuat tekan yang terbaca pada manometerdipakai sebagai dasar untuk beban stressing. Dan pengukuran perpanjangan strand dipakai penggaris besi.

Setiap titik ground angkur akan ditarik sampai 125 % beban rencana dan dikunci pada 115 % dari beban rencana.

Siklus stressing dapat dilihat pada Tabel 1 dibawah ini :

V. CAMPURAN GROUTING DAN KEKUATAN

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Load Increment (% Tw) Period of Observation (min)

10501001251005010

11115111


Air = 21 – 22.5 ltr Semen = 50 kg Add. Tricosal = 500 grams W/C Ratio = 0.42 – 0.45 Kuat Tekan 7d = 30 N/mm2 Kuat Tekan 28d = 40 N/mm2

Terlampir brosur dari additive TRICOSAL 181

VI. MATERIAL SPECIFICATIONAn anchor is deemed to be satisfactory if :

It can hold the proof load of 125 % of the working load.

The apparent free tendon length is not less than 90 % of the design free length nor more than design free length + 50 % tendon bond length.

Item Materials

1

2

3

4

PC Strand, dia 12.7 mm Stress Relieve 7 wire, grade 270

Ordinary Portland Cement

Water

Non-Shrink Addditive – Tricosal 181

VII. QUALITY CONTROL

The fpllowing quality control checks shall be taken during the course of works :

Item Quality Control Check

123456

PositionAlignementInclinationDrill LengthAnchor Tendon Installed LengthGrout Strength

VI. SPESIFIKASI MATERIALSuatu angkur dikatakan bagus jika :

Dapat menahan proof load sebesar 125 % dari beban kerja

Panjang sebenarnya free length tidak kurang dari 90 % dari disain free length atau tidak lebih dari disain free length + 50 % tendon bond.

Specification Code

ASTM A 416 Min Breaking Load 183.7 kN

See Attached Brochure

VII. KONTROL KUALITASDalam mengikuti control kualitas pekerjaan, maka harus dipenuhi beberapa hal :

Method Checking

Theodolite / Measuring Tape

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Survey / Measuring TapeAngle FinderNumber of Drill Rods Measuring TapeUnconfined Compression Test

The tolerances and frequencies of the above checks are listed in the quality control check list.

VIII. RECORDING FORMS

The following recording forms shall be submitted during the progress of work :

1. Daily Report2. Ground Anchor Installation Record3. Groung Anchor Stressing Records

Sample of the above recording forms is attached.

IX. EQUIPMENTS

The following are the main equipment that will be used for this project.

1. Drill Rig 2 Nos2. Grout Mixer 2 Sets3. Grout Pump 2 Nos4. Stressing Jack 200 T 2 Nos5. Twin Hydraulic Pump 2 Nos

Toleransi dan frekuensimdari pengecekan diatas telah terdapat pada daftar control kualitas (terlampir).

VIII. LEMBARAN REKAMAN

Lembaran – lembaran rekaman akan diberikan selama pelaksanaan pekerjaan.

1. Laporan harian2. Rekaman Pemasangan Ground Angkur3. Rekaman Stressing Ground Angkur

Contoh dari semua rekaman diatas terlampir.

IX. PERALATAN

Berikut daftar peralatan utama yang akan dipakai di proyek ini :

1. Drill Rig 2 unit2. Grout Mixer 2 Set3. Grout Pump 2 unit4. Stressing Jack 200 T 2 unit5. Twin Hydraulic Pump 2 unit

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