RE-MOVEABLE PONDASI COMPRESSOR ENGINE PACKAGE MENGGUNAKAN SEGMENTAL PRE-STRESSED CONCRETE PAD

14 10 2008

Proyek ini telah beberapa bulan selesai, yaitu pemasangan well head compressor yang bertujuan untuk menaikan tekanan gas dari sumur agar dapat dikirim ke stasiun pengumpulan. Package compressor ini dipasang pada sumur-sumur gas yang sudah tua sehingga konsep dasarnya pemasangan package compressor ini bersifat temporary dalam kurum waktu hitungan bulan.

 

Mengingat pemasangannya yang bersifat sementara, maka fasilitas – fasilitas penunjangnya harus dibuat flexible, termasuk didalamnya adalah pondasi dudukan package compressor tersebut sehingga mudah untuk dipindahkan ke sumur gas yang lain tanpa harus membuat baru lagi dan dalam waktu yang lebih singkat (kan lucu, jika fase constructionya bisa lebih lama dari fase operation).

 

Awalnya saya ragu, apakah kami bisa merencanakan pondasi seperti requirements diatas (dapat dipindahkan), mengingat selama ini rule of thumb dari perencanaan pondasi mesin adalah berat pondasi minimal 2.5 kali terhadap berat mesin + compressor. Sementara informasi yang kami dapatkan dari manufacture package compressor bahwa berat compressor package kisaran 25 ton, artinya berat pondasi minimal 62.5 ton.

 

Langkah pertama yang kami lakukan adalah meminta perhitungan berat dari masing-masing component compressor package pada manufacturer, sehingga dari data tersebut diketahui bahwa berat engine + compressor tidak lebih dari 5 ton, selebihnya adalah berat skid beserta accessories dari compressor package tersebut. Selain itu kami juga meminta loading data dari compressor package dimana diketahui nilai excitation force akibat unbalance mass tidak lebih dari 10 kg per titik anchor bolt.

 

Hal ini menunujukan bahwa, excitation force akibat unbalance force dari engine dan compressor didesign sudah dapat ditahan oleh skidnya sendiri, sehingga pondasi dibutuhkan hanya untuk menahan beban gravitas dari package compressor tersebut agar tidak terjadi penurunan yang belebihan serta penurunan yang tidak mereta, juga pengechekan terhadap daya dukung tanah ijin.

 

Untuk tujuan dari pondasi yang kami sebutkan diatas, akhirnya kami memutuskan menggunakan pre-stressed concrete pad (panjang 2 meter, lebar 1 meter, tebal 15 cm) yang disusun dengan rapih diatas lapisan pasir batu (sirtu) yang telah dipadatkan setebal 20 cm dan diberi curb disekelilinya agar sirtu tersebut dapat saling interlocking.

 

Untuk perhitungan pre-stressed concrete pad dilakukan oleh vendor supplier-nya dengan dimodelkan menggunakan software berbasis finite element serta lapisan sirtu tersebut dihitung kekakuannya untuk dimodelkan sebagai spring yang menopang concrete pad tersebut. Dari data hasil analisis tersebut dapat diketahui nilai gaya geser, gaya axial serta momen yang harus ditahan oleh concrete pad tersebut untuk selanjutnya digunakan untuk mendesign kebutuhan jumlah strand dari pre-stressed concrete pad tersebut.

 

Sisi lain yang juga harus dicheck saat mendesign pre-stressed concrete pad adalah, momen serta gaya yang timbul saat concrete pad tersebut diangkat untuk dipindahkan dari satu tempat ketempat lain termasuk mendesign letak titik angkat beserta detil dari titik angkat tersebut.

 

Alhamdulillah saat ini compressor package tersebut sekarang telah running dengan baik, dan hanya butuh waktu kurang dari 10 hari untuk memindahkannya termasuk pondasinya dan memasang kembali unit tersebut.

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EVALUASI INTEGRITAS PIPA BERTEKANAN TERTANAM DENGAN PENAMBAHAN BEBAN KENDARAAN

7 10 2008

Diakhir ramadhan kemarin, saya medapatkan tugas dari atasan untuk melakukan evaluasi integritas existing pipa bertekanan yang dialiri liquid dan tertanam dikarenakan adanya pembuatan jalan yang melintas diatas jalur pipa tersebut. Evaluasi ini dimaksudkan untuk mengetahui jenis kendaraan yang diijinkan melintas tanpa mengakibatkan kerusakan pada pipa.

 

 

Pada dasarnya terdapat dua pilihan yang dapat dilakukan untuk kasus semacam ini; 1. Menentukan jenis kendaraan maximum yang bakal lewat, kemudian melakukan evaluasi perlu tidaknya membuat pipe culvert untuk melindungi line pipa tersebut, 2. Membatasi jenis kendaraan yang boleh lewat, sehingga line pipa tidak mengalami kerusakan tanpa penambahan pipe protection. Mengingat fungsi jalan yang bersifat sekunder dan untuk meminimize cost, maka pilihan nomor dua dirasa paling tepat untuk kasus saya kali ini.

 

Berikut kutipan dari executive summary dari laporan hasil evaluasi tersebut:

“This report contains of the structural integrity analysis for U/G pipelines. The U/G pipelines are liquid line service, located at crossing road –deleted by badar- (Indonesia). 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 Silakan unduh di link ini untuk melihat detil perhitungan yang saya lakukan.

http://ifile.it/gyufnz7
http://ifile.it/6lcrnjx

 

Referensi yang digunakan dalam penulisan laporan ini :

  1. ASME B31.4, “Liquid Transportation Systems For Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, and Alcohols, “American Society of Mechanical Engineers, New York.
  2. ASCE, 1995, “Guidelines for the Design of Buried Steel Pipe”, American Society of Civil Engineers.
  3. Watkins, R.K. and Anderson, L.R 1999, “Structural Mechanics of Buried Pipes”, New York.

 

 

 

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 Silakan unduh di link ini untuk melihat detil perhitungan yang saya lakukan.

 

Referensi yang digunakan dalam penulisan laporan ini :

  1. ASME B31.4, “Liquid Transportation Systems For Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, and Alcohols, “American Society of Mechanical Engineers, New York.
  2. ASCE, 1995, “Guidelines for the Design of Buried Steel Pipe”, American Society of Civil Engineers.
  3. Watkins, R.K. and Anderson, L.R 1999, “Structural Mechanics of Buried Pipes”, New York.

 

 

 

 

 

 

 

 

 

 

The U/G pipelines are crossed by Access road to –deleted by badar-, attached to the sand soil with 2 m depth. The U/G pipelines are owned and operated by –deleted by badar. Engineering & Construction Dept. –deleted by badar- performing an analysis appraisal to assess the integrity of the pipelines structure. The scopes of works are visual inspection and structure analysis consider with external load due to truck according AASHTO (The American Association of State Highway & Transportation Officials) .

 

 

The U/G pipelines are crossed by Access road to –deleted by badar-, attached to the sand soil with 2 m depth. The U/G pipelines are owned and operated by –deleted by badar. Engineering & Construction Dept. –deleted by badar- performing an analysis appraisal to assess the integrity of the pipelines structure. The scopes of works are visual inspection and structure analysis consider with external load due to truck according AASHTO (The American Association of State Highway & Transportation Officials) .

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 Silakan unduh di link ini untuk melihat detil perhitungan yang saya lakukan.

 

Referensi yang digunakan dalam penulisan laporan ini :

  1. ASME B31.4, “Liquid Transportation Systems For Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, and Alcohols, “American Society of Mechanical Engineers, New York.
  2. ASCE, 1995, “Guidelines for the Design of Buried Steel Pipe”, American Society of Civil Engineers.
  3. Watkins, R.K. and Anderson, L.R 1999, “Structural Mechanics of Buried Pipes”, New York.

 

 

 

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 Silakan unduh di link ini untuk melihat detil perhitungan yang saya lakukan.

 

Referensi yang digunakan dalam penulisan laporan ini :

  1. ASME B31.4, “Liquid Transportation Systems For Hydrocarbons, Liquid Petroleum Gas, Anhydrous Ammonia, and Alcohols, “American Society of Mechanical Engineers, New York.
  2. ASCE, 1995, “Guidelines for the Design of Buried Steel Pipe”, American Society of Civil Engineers.
  3. Watkins, R.K. and Anderson, L.R 1999, “Structural Mechanics of Buried Pipes”, New York.

 

 

 

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

 
 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”

 

 

 

 

 

 

 

 

 

 
 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The purpose of structural analysis for this U/G pipelines are to check the adequacy of the strength and stiffness of its structure to withstand the loads imposed by operational activities and environmental loads during operation, truck load. Ultimately the purpose of the analysis is to establish a necessary recommendation aimed to ensure U/G pipelines structure reliability.

 

 

 

 

 

 

 

The scopes of works consist of:

  1. Collecting data i.e.: Drawing, design basis and site check for depth of soil cover.
  2. The structural analysis considering its geometry and additional external load due to truck load.
  3. In the structural analyses, all members are checked by referring the specified minimum yield strength (SMYS) at ASME B31.4 “Liquid Transmission and Distribution Piping System”.
  4. The analyses consider the in-site loading cases and its geometry.

Based on the data and analyses it can be concluded as follows:

  1. The U/G pipelines are considered acceptable to be operated in its planned service time.
  2. The U/G pipelines have sufficient structural reserve capacity to withstand truck loads conditions during its operations. Any other vehicle load condition such as low buoy should not be allowed, unless re-engineering analysis shows that it is acceptable.”