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12-28-2012, 12:46 AM
الفرق بين retrofit و re**vate
دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
Seismic Retrofit Training For Building Contractors Inspectors.pdf (http://www.mediafire.com/view/?6g01fgc5x9tw8v7)
دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
file:///C:/Users/Amin/AppData/Local/Temp/msohtmlclip1/01/clip_image002.giffile:///C:/Users/Amin/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif
دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
والرابط المرفق يشرح موضوع اعادة التجهيز ( Retrofit ) والخبرة اليابانية في ما يتعلق بتقوية المنشآت من ناحية زلزالية.
Seismic Design Practice in Japan.
Seismic Retrofit Training For Building Contractors Inspectors.pdf (http://www.mediafire.com/view/?6g01fgc5x9tw8v7)
file:///C:/Users/Amin/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif
دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
Seismic Retrofit Training For Building Contractors Inspectors.pdf (http://www.mediafire.com/view/?6g01fgc5x9tw8v7)
دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
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دخل ال**طلح RETROFIT في الاستخدام من عهد قريب وهو منحوت من كلمتين الاولى هي
RETROACTIVE وتعني بأثر رجعي والثانية REFIT وتعني الاصلاح , الضبط , التجديد والتعديل, وتعني ايضا التجهيز مجددا ويصبح المعنى لل**طلح كاملا هو تجهيز شيء موجود سواء كان الة او معدة او مبنى او منشأ او جزءا من منشأ قائم بوسائل او مكونات جديدة لم تكن موجودة وقت الانشاء الاصلي بما يؤدي لتحسين الاداء سواء للالة او المنشأ وكذلك تقوية المنشأ القديم بحيث يصبح متوافقا مع معايير جديدة (مواصفة جديدة على سبيل المثال) لم تكن موضوعة وقت التصنيع او الانشاء الاصلي وهذا ما تعنيه كلمة RETROACTIVE وبالرجوع الى الفقرات التالية المقتطفة من Wai-Fah Chen Bridge Engineering Handbook Edited by يبين الكاتب ان دراسة لتقييم احوال الجسور بعد زلزال سان فراسسكو عام 1971 ونتيجة للدراسة تقرر اجراء عمليات التجديد واعادة التجهيز retrofitting لحوالي 3200 جسر من بين 18000 جسر خضعت للتقييم وكانت القصد اعادة تاهيل هذه الجسور باضافة عناصر تقوية بطرق مختلفة بناء على المعلومات والوسائل والمعارف التي اصبحت متوفرة وقت الدراسة بالاضافة الى جعلها مطابقة للمواصفات الجديدة والتي لم تكن موجودة وقت انشاء هذه الجسور . وشيء شبيه ايضا حصل مع عدد ضخم من الجسور في اليابان نتيجة للتقييم الذي الذي كان يتم عقب الزلازل العديدة التي حدثت في اوقات مختلفة وبالنتيجة خضع حوالي 18000 جسر في اليابان لخطة اعادة التجهيز retrofitting من بين 60000 جسر .
واما ال**طلح الاخر RE**VATE فهو يعني عمليات الترميم ةالتجديد التي تتم للمنشآت والمباني عموما بقصد اعادة وضعها الى ما كانت عليه وقت انشائها دون ان يتطلب ذلك اعمال تقوية او اضافات كتلك التي تتم عند عمل ال RETROFIT .
44.5 Seismic Retrofit Practices for Highway Bridges
44.5.1 Past Seismic Retrofit Practices
The Ministry of Construction has conducted seismic evaluations of highway bridges throughout the country five times since 1971 as a part of the comprehensive earthquake disaster prevention measures for highway facilities. Seismic retrofit for vulnerable highway bridges had been successively made based on the seismic evaluations. Table 44.11 shows the history of past seismic evaluations[7,8].
The first seismic evaluation was made in 1971 to promote earthquake disaster prevention measures for highway facilities. The significant damage of highway bridges caused by the 1971 San Fernando earthquake in the United States triggered the seismic evaluation. Highway bridges with span lengths longer than or equal to 5 m on all systems of national expressways and highways were evaluated. Attention was paid to detect deterioration such as *****s of reinforced concrete structures, tilting, sliding, settlement, and scouring of foundations. Approximately 18,000 highway bridges in total were evaluated and approximately 3200 bridges were found to require retrofit.
Following the first, seismic evaluations had been subsequently made in 1976, 1979, 1986, and 1991 with gradually expanding highways and evaluation items. The seismic evaluation in 1986 was made with the increase of social needs to ensure seismic safety of highway traffic after the damage caused by the Urakawa-oki earthquake in 1982 and the Nihon-kai-chubu earthquake in 1983. The highway bridges with span lengths longer than or equal to 15 m on all systems of national expressways,national highways and principal local highways, and overpasses were evaluated. The evaluation items included deterioration, unseating prevention devices, strength of substructures, and stability of foundations. Approximately 40,000 bridges in total were evaluated and approximately 11,800 bridges were found to require retrofit. The latest seismic evaluation was made in 1991. The number
of highways to be evaluated has increased from the number evaluated in 1986. Approximately 60,000 bridges in total were evaluated and approximately 18,000 bridges were found to require retrofit.
Through a ****** of seismic retrofit works, approximately 32,000 bridges were retrofitted by the end of 1994.
FIGURE 44.14 Seismic retrofit of reinforced concrete piers by steel jacket with controlled increase of flexural strength.
والرابط المرفق يشرح موضوع اعادة التجهيز ( Retrofit ) والخبرة اليابانية في ما يتعلق بتقوية المنشآت من ناحية زلزالية.
Seismic Design Practice in Japan.
Seismic Retrofit Training For Building Contractors Inspectors.pdf (http://www.mediafire.com/view/?6g01fgc5x9tw8v7)
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