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Cracks seen in the flyover pillar

bluesky

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ফ্লাইওভারের পিলারে ফাটল: ‘ভয়ের কিছু’ দেখছে না তদন্ত কমিটি
এফই অনলাইন ডেস্ক | Published: November 02, 2021 19:33:11
ফাইল ছবি (সংগৃহীত)
ফাইল ছবি (সংগৃহীত)


চট্টগ্রাম নগরীর বহদ্দারহাটে এম এ মান্নান ফ্লাইওভারের র‍্যাম্পের পিলারে ফাটলের ঘটনায় সিটি করপোরেশনের গঠিত ‘নিরপেক্ষ’তদন্ত কমিটি ঘটনাস্থল পরিদর্শন করেছে।
এ বিষয়ে ‘দ্রুততম সময়ে’সিটি করপোরেশনে প্রতিবেদন দেওয়া হবে জানিয়ে তদন্ত দলের সদস্য অধ্যাপক ড. মোহাম্মদ আবদুর রহমান ভুঁইয়া বলেছেন, “আপনারা সেখান থেকে জানতে পারবেন। তবে আপাত দৃষ্টিতে যা মনে হল, ভয়ের কিছু নেই।”
চট্টগ্রাম প্রকৌশল ও প্রযুক্তি বিশ্ববিদ্যালয়ের (চুয়েট) সিভিল ইঞ্জিনিয়ারিং বিভাগের অধ্যাপক এবং ইন্সটিটিউট অব আর্থকোয়েক ইঞ্জিনিয়ারিং রিসার্চ এর পরিচালক অধ্যাপক ড. মোহাম্মদ আবদুর রহমান ছাড়া সড়ক ও জনপথ বিভাগের তত্ত্বাবধায়ক প্রকৌশলী মো. হাফিজুর রহমান এ কমিটির সদস্য।

মঙ্গলবার দুপুরে তারা যখন ফ্লাইওভারের ওই র‍্যাম্পটি দেখছিলেন, চট্টগ্রাম সিটি করপোরেশনের প্রধান প্রকৌশলী রফিকুল ইসলাম মানিকও ছিলেন তাদের সঙ্গে। খবর বিডিনিউজ টোয়েন্টিফোর ডটকমের।
গত ২৫ অক্টোবর রাতে নগরীর বহদ্দারহাট মোড়ে এম এ মান্নান ফ্লাইওভারের র‍্যাম্পের পিলারে ফাটল দেখা দেওয়ার খবর ছড়িয়ে পড়ে। রাতেই পুলিশ ওই র‍্যাম্প যানবাহন চলাচল বন্ধ করে দেয়।
এম এ মান্নান ফ্লাইওভারটি চট্টগ্রাম উন্নয়ন কর্তৃপক্ষ (সিডিএ) নির্মাণ করে। ২০১৯ সালের ডিসেম্বরে হস্তান্তরের পর থেকে এর রক্ষণাবেক্ষণের দায়িত্ব সিটি করপোরেশনের।
প্রধান প্রকৌশলী রফিকুল ইসলাম বলেন, “সম্ভব হলে আগামীকালের মধ্যেই প্রতিবেদন দিতে বলেছি। তদন্ত প্রতিবেদন পেলে সে অনুসারে ব্যবস্থা নেব।”
পরিদর্শনের পর ফাটলের বিষয়ে মতামত জানতে চাইলে তিনি বলেন, “আমাদের মতামত আমরা আগেই বলেছি। এখন তদন্ত চলাকালে মন্তব্য করা ঠিক হবে না। প্রতিবেদন পেলে আপনাদের জানাব।”
২৬ অক্টোবর দুপুরে ফ্লাইওভারটি পরিদর্শনে গিয়ে সিটি মেয়র এম রেজাউল করিম এবং চট্টগ্রাম সিটি করপোরেশনের প্রধান প্রকৌশলী রফিকুল ইসলাম ফাটল দেখে র‍্যাম্পের নির্মাণ ক্রুটি অথবা নকশাগত ত্রুটি থাকতে পারে বলে মন্তব্য করেছিলেন।
ওইদিন সকালে ফ্লাইওভারটির নির্মাণকারী প্রতিষ্ঠান চট্টগ্রাম উন্নয়ন কর্তৃপক্ষের (সিডিএ) প্রকল্প পরিচালক মাহফুজুর রহমান বলেছিলেন, হালকা গাড়ির জন্য তৈরি র‍্যাম্পে ভারী গাড়ি চলায় ফাটল হতে পারে। তবে সেদিন বিকেলে তিনি গণমাধ্যমের কাছে দাবি করেন, সেখানে কোনো ‘ফাটল হয়নি’।
পরদিন ২৭ অক্টোবর নকশা প্রণয়নকারী কোম্পানি ডিজাইন প্ল্যানিং অ্যান্ড ম্যানেজমেন্ট (ডিপিএম) কনসালটেন্ট লিমিটেড এবং ঠিকাদারি কোম্পানি ম্যাক্স গ্রুপের বিশেষজ্ঞরা পরিদর্শন শেষে দাবি করেন, ফ্লাইওভারের পিলারে কোনো ফাটল নেই, যা দেখা যাচ্ছে তা হল ‘কনস্ট্রাকশন জয়েন্ট’।
র‍্যাম্পটি হালকা যানবাহন চলাচলের জন্য নকশা করা হলেও সেখানে ভারী যানবাহন চলাচল করার বিষয়টি দুই সংস্থাই স্বীকার করেছে। তবে র‍্যাম্পের শুরুতে ‘হাইট বেরিয়ার’ না থাকার জন্য পরস্পরকে দায়ী করছে সরকারি সেবা সংস্থা দুটি।
১০৬ কোটি টাকা ব্যয়ে বন্দরনগরীর চান্দগাঁও থানা এলাকা থেকে বহদ্দারহাট মোড় পর্যন্ত ১ দশমিক ৩৩ কিলোমিটার এ ফ্লাইওভারটি ২০১৩ সালের অক্টোবরে প্রধানমন্ত্রী তা উদ্বোধন করেন।এর নির্মাণ কাজ শুরু হয় ২০১০ সালের ডিসেম্বরে। সিডিএ ১০৬ কোটি টাকা ব্যয়ে নিজস্ব অর্থায়নে এ ফ্লাইওভার নির্মাণ করে।
স্থানীয়দের দাবির নির্মিত র‍্যাম্পটি প্রায় চার বছর পর ২০১৭ সালের ডিসেম্বরে চালু করা হয়। ২০১৯ সালের ডিসেম্বরে ফ্লাইওভারটি রক্ষণাবেক্ষণের জন্য সিটি করপোরেশনকে হস্তান্তর করে সিডিএ।


Cracks seen in the flyover pillar

A 'neutral' investigation committee formed by the City Corporation has visited the spot in the incident of a crack in the pillar of the ramp of MA Mannan flyover at Bahaddarhat in Chittagong city.

A report will be submitted to the city corporation at the earliest, said a member of the investigation team, Prof. Mohammad Abdur Rahman Bhuiyan said, “You can find out from there. But at first glance, there is nothing to fear. ”

Chittagong University of Engineering and Technology (CUET) Professor of Civil Engineering and Director of the Institute of Earthquake Engineering Research. Mohammad Abdur Rahman, the supervising engineer of the Department of Roads and Highways. Hafizur Rahman is a member of this committee.

Rafiqul Islam Manik, chief engineer of Chittagong City Corporation, was also with them when they saw the ramp on the flyover on Tuesday afternoon. News from bdnews24.com.

On the night of October 25, news spread that a crack had appeared in the pillar of the ramp of MA Mannan flyover at Bahaddarhat corner of the city. During the night, the police stopped the traffic on the ramp.

The MA Mannan flyover was constructed by the Chittagong Development Authority (CDA). Since its handover in December 2019, the City Corporation has been responsible for its maintenance.

Chief Engineer Rafiqul Islam said, “I have asked to submit the report by tomorrow if possible. I will take action accordingly after receiving the investigation report. ”

Asked for his opinion on the crack after the inspection, he said, "We have already stated our opinion. Now it would not be right to comment during the investigation. I will let you know when I get the report. ”

While inspecting the flyover at noon on October 26, City Mayor M Rezaul Karim and Chittagong City Corporation Chief Engineer Rafiqul Islam saw cracks and commented that the ramp may have construction defects or design defects.
That morning, Mahfuzur Rahman, project director of the Chittagong Development Authority (CDA), the company that built the flyover, said heavy vehicles could crack on the ramps made for light vehicles. However, he claimed to the media that afternoon that there was no 'crack'.

The next day, on October 26, experts from Design Planning and Management (DPM) Consultants Limited and Max Group, a contractor, claimed that there were no cracks in the pillars of the flyover, which appeared to be a 'construction joint'.

Although the ramp is designed for light vehicles, both companies have acknowledged that there is heavy traffic. However, the two government service agencies are blaming each other for not having a 'height barrier' at the beginning of the ramp.

The 1.33 km flyover from Chandgaon Thana area of the port city to Bahaddarhat junction was inaugurated by the Prime Minister in October 2013 at a cost of Taka 106 crore. The construction work started in December 2010. CDA constructed the flyover at its own expense at a cost of Tk 108 crore.

The ramp, built by locals, was launched in December 2016, almost four years later. In December 2019, the CDA handed over the flyover to the City Corporation for maintenance.
 
Probably the result of an earthquake shear motion, or overloading.

In the US, this would cause govts. to demolish this thing and start over.

In Bangladesh, life is cheap so maybe they will do nothing...

These Mo Fo idiots let 20 ton trucks ply on this thing, which was designed only for passenger vehicles.

A simple height barrier could have prevented this mishap. Uneducated people all over the subcontinent shooting themselves in their own feet.
 
Probably the result of an earthquake shear motion, or overloading.

In the US, this would cause govts. to demolish this thing and start over.

In Bangladesh, life is cheap so maybe they will do nothing...

These Mo Fo idiots let 20 ton trucks ply on this thing, which was designed only for passenger vehicles.

A simple height barrier could have prevented this mishap. Uneducated people all over the subcontinent shooting themselves in their own feet.
Bold part: A bridge or an overhead highway design must comply with the AASHTO (American Association of State Highway and Transportation Officials) loading. An overhead bridge must be designed to take the maximum vehicle loads. Please read an AASHTO paragraph.

"The total vehicle (design) weight is 72 kilopounds/ 32.7 tons with the axle weights and spacing of the design truck".

Please note that 32 kips at the back and middle of a truck is about 44.5% of the total 72 kips. Well, this is AASHTO design loading always giving importance to the safety of the bridge column, beam, or floor slab.

We are all proud of these structures being built by our military engineers. But I have reasons to believe that they just do the construction without the pains of learning from design engineers of developed countries and re-do similar design analysis.

Why do I think so? It is because I have seen very tall columns in flyovers in Mahakhali which are without the provision of vertical bracings that surprised me. Euler's rule on slenderness ratio was not followed because the design engineers just do not know or understand what it is.

By the way, I have reasons to believe that the cracks were caused by the heavy bending momemt (BM) force during an earthquake swaying the heavy slab/ carriageway that caused cracks in the pillar.

Well, it is just my guess!!! Less amount of steel main bars and wide spacing of tie bars was unable to withstand this large bending moment.

1635901291488.png
 
Bold part: A bridge or an overhead highway design must comply with the AASHTO (American Association of State Highway and Transportation Officials) loading. An overhead bridge must be designed to take the maximum vehicle loads. Please read an AASHTO paragraph.

"The total vehicle (design) weight is 72 kilopounds/ 32.7 tons with the axle weights and spacing of the design truck".

Please note that 32 kips at the back and middle of a truck is about 44.5% of the total 72 kips. Well, this is AASHTO design loading always giving importance to the safety of the bridge column, beam, or floor slab.

We are all proud of these structures being built by our military engineers. But I have reasons to believe that they just do the construction without the pains of learning from design engineers of developed countries and re-do similar design analysis.

Why do I think so? It is because I have seen very tall columns in flyovers in Mahakhali which are without the provision of vertical bracings that surprised me. Euler's rule on slenderness ratio was not followed because the design engineers just do not know or understand what it is.

By the way, I have reasons to believe that the cracks were caused by the heavy bending momemt (BM) force during an earthquake swaying the heavy slab/ carriageway that caused cracks in the pillar.

Well, it is just my guess!!! Less amount of steel main bars and wide spacing of tie bars was unable to withstand this large bending moment.


View attachment 789768

Excellent analysis - learned a lot @bluesky bhai.

I doubt that the design of the cracked column was done by the Army 24th Engg. Brigade who was involved in the other major projects such as Padma Bridge and the Purbachal Expressway. Probably done by a local firm in Chittagong who got the bid at the lowest quoted price. I suspect they used more sand than cement and also used less re-bars than the specs called for. Once the demolition starts and details get divulged (and the firm gets sued), their future will be over. At least it should. There is such a thing called performance guarantee.

The Dhaka elevated expressway columns also look rather slender to me - they definitely won't be able to take loads of heavy trucks. But our Roads and Highways dept. idiots have no precautions to prevent heavy trucks from getting on these expressways.

iu


All are disasters waiting to happen...

By the way - In the US the Semi tractors and trailers in the US have a lot more load as the tractor has three axles and the trailer at least two. In Europe, the trailers have three axles. So if the KIPs per axle being the same, it would be a lot more load. Some of the newer semi trucks being used in Bangladesh nowadays are very heavy like American Semi trucks.

iu


8a83841cc7f56a7522c28c1db6185c1a.gif
 
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Probably the result of an earthquake shear motion, or overloading.

In the US, this would cause govts. to demolish this thing and start over.

In Bangladesh, life is cheap so maybe they will do nothing...

These Mo Fo idiots let 20 ton trucks ply on this thing, which was designed only for passenger vehicles.

A simple height barrier could have prevented this mishap. Uneducated people all over the subcontinent shooting themselves in their own feet.
Bruh this fat *** pillar cracks it’s *** with 20th load then what’s the use of making em so fat?
atleast elevated expressway and the flyover around passport office had decent space left below.
 

ফ্লাইওভারের পিলারে ফাটল: ‘ভয়ের কিছু’ দেখছে না তদন্ত কমিটি
এফই অনলাইন ডেস্ক | Published: November 02, 2021 19:33:11
ফাইল ছবি (সংগৃহীত)
ফাইল ছবি (সংগৃহীত)


চট্টগ্রাম নগরীর বহদ্দারহাটে এম এ মান্নান ফ্লাইওভারের র‍্যাম্পের পিলারে ফাটলের ঘটনায় সিটি করপোরেশনের গঠিত ‘নিরপেক্ষ’তদন্ত কমিটি ঘটনাস্থল পরিদর্শন করেছে।
এ বিষয়ে ‘দ্রুততম সময়ে’সিটি করপোরেশনে প্রতিবেদন দেওয়া হবে জানিয়ে তদন্ত দলের সদস্য অধ্যাপক ড. মোহাম্মদ আবদুর রহমান ভুঁইয়া বলেছেন, “আপনারা সেখান থেকে জানতে পারবেন। তবে আপাত দৃষ্টিতে যা মনে হল, ভয়ের কিছু নেই।”
চট্টগ্রাম প্রকৌশল ও প্রযুক্তি বিশ্ববিদ্যালয়ের (চুয়েট) সিভিল ইঞ্জিনিয়ারিং বিভাগের অধ্যাপক এবং ইন্সটিটিউট অব আর্থকোয়েক ইঞ্জিনিয়ারিং রিসার্চ এর পরিচালক অধ্যাপক ড. মোহাম্মদ আবদুর রহমান ছাড়া সড়ক ও জনপথ বিভাগের তত্ত্বাবধায়ক প্রকৌশলী মো. হাফিজুর রহমান এ কমিটির সদস্য।

মঙ্গলবার দুপুরে তারা যখন ফ্লাইওভারের ওই র‍্যাম্পটি দেখছিলেন, চট্টগ্রাম সিটি করপোরেশনের প্রধান প্রকৌশলী রফিকুল ইসলাম মানিকও ছিলেন তাদের সঙ্গে। খবর বিডিনিউজ টোয়েন্টিফোর ডটকমের।
গত ২৫ অক্টোবর রাতে নগরীর বহদ্দারহাট মোড়ে এম এ মান্নান ফ্লাইওভারের র‍্যাম্পের পিলারে ফাটল দেখা দেওয়ার খবর ছড়িয়ে পড়ে। রাতেই পুলিশ ওই র‍্যাম্প যানবাহন চলাচল বন্ধ করে দেয়।
এম এ মান্নান ফ্লাইওভারটি চট্টগ্রাম উন্নয়ন কর্তৃপক্ষ (সিডিএ) নির্মাণ করে। ২০১৯ সালের ডিসেম্বরে হস্তান্তরের পর থেকে এর রক্ষণাবেক্ষণের দায়িত্ব সিটি করপোরেশনের।
প্রধান প্রকৌশলী রফিকুল ইসলাম বলেন, “সম্ভব হলে আগামীকালের মধ্যেই প্রতিবেদন দিতে বলেছি। তদন্ত প্রতিবেদন পেলে সে অনুসারে ব্যবস্থা নেব।”
পরিদর্শনের পর ফাটলের বিষয়ে মতামত জানতে চাইলে তিনি বলেন, “আমাদের মতামত আমরা আগেই বলেছি। এখন তদন্ত চলাকালে মন্তব্য করা ঠিক হবে না। প্রতিবেদন পেলে আপনাদের জানাব।”
২৬ অক্টোবর দুপুরে ফ্লাইওভারটি পরিদর্শনে গিয়ে সিটি মেয়র এম রেজাউল করিম এবং চট্টগ্রাম সিটি করপোরেশনের প্রধান প্রকৌশলী রফিকুল ইসলাম ফাটল দেখে র‍্যাম্পের নির্মাণ ক্রুটি অথবা নকশাগত ত্রুটি থাকতে পারে বলে মন্তব্য করেছিলেন।
ওইদিন সকালে ফ্লাইওভারটির নির্মাণকারী প্রতিষ্ঠান চট্টগ্রাম উন্নয়ন কর্তৃপক্ষের (সিডিএ) প্রকল্প পরিচালক মাহফুজুর রহমান বলেছিলেন, হালকা গাড়ির জন্য তৈরি র‍্যাম্পে ভারী গাড়ি চলায় ফাটল হতে পারে। তবে সেদিন বিকেলে তিনি গণমাধ্যমের কাছে দাবি করেন, সেখানে কোনো ‘ফাটল হয়নি’।
পরদিন ২৭ অক্টোবর নকশা প্রণয়নকারী কোম্পানি ডিজাইন প্ল্যানিং অ্যান্ড ম্যানেজমেন্ট (ডিপিএম) কনসালটেন্ট লিমিটেড এবং ঠিকাদারি কোম্পানি ম্যাক্স গ্রুপের বিশেষজ্ঞরা পরিদর্শন শেষে দাবি করেন, ফ্লাইওভারের পিলারে কোনো ফাটল নেই, যা দেখা যাচ্ছে তা হল ‘কনস্ট্রাকশন জয়েন্ট’।
র‍্যাম্পটি হালকা যানবাহন চলাচলের জন্য নকশা করা হলেও সেখানে ভারী যানবাহন চলাচল করার বিষয়টি দুই সংস্থাই স্বীকার করেছে। তবে র‍্যাম্পের শুরুতে ‘হাইট বেরিয়ার’ না থাকার জন্য পরস্পরকে দায়ী করছে সরকারি সেবা সংস্থা দুটি।
১০৬ কোটি টাকা ব্যয়ে বন্দরনগরীর চান্দগাঁও থানা এলাকা থেকে বহদ্দারহাট মোড় পর্যন্ত ১ দশমিক ৩৩ কিলোমিটার এ ফ্লাইওভারটি ২০১৩ সালের অক্টোবরে প্রধানমন্ত্রী তা উদ্বোধন করেন।এর নির্মাণ কাজ শুরু হয় ২০১০ সালের ডিসেম্বরে। সিডিএ ১০৬ কোটি টাকা ব্যয়ে নিজস্ব অর্থায়নে এ ফ্লাইওভার নির্মাণ করে।
স্থানীয়দের দাবির নির্মিত র‍্যাম্পটি প্রায় চার বছর পর ২০১৭ সালের ডিসেম্বরে চালু করা হয়। ২০১৯ সালের ডিসেম্বরে ফ্লাইওভারটি রক্ষণাবেক্ষণের জন্য সিটি করপোরেশনকে হস্তান্তর করে সিডিএ।


Cracks seen in the flyover pillar

A 'neutral' investigation committee formed by the City Corporation has visited the spot in the incident of a crack in the pillar of the ramp of MA Mannan flyover at Bahaddarhat in Chittagong city.

A report will be submitted to the city corporation at the earliest, said a member of the investigation team, Prof. Mohammad Abdur Rahman Bhuiyan said, “You can find out from there. But at first glance, there is nothing to fear. ”

Chittagong University of Engineering and Technology (CUET) Professor of Civil Engineering and Director of the Institute of Earthquake Engineering Research. Mohammad Abdur Rahman, the supervising engineer of the Department of Roads and Highways. Hafizur Rahman is a member of this committee.

Rafiqul Islam Manik, chief engineer of Chittagong City Corporation, was also with them when they saw the ramp on the flyover on Tuesday afternoon. News from bdnews24.com.

On the night of October 25, news spread that a crack had appeared in the pillar of the ramp of MA Mannan flyover at Bahaddarhat corner of the city. During the night, the police stopped the traffic on the ramp.

The MA Mannan flyover was constructed by the Chittagong Development Authority (CDA). Since its handover in December 2019, the City Corporation has been responsible for its maintenance.

Chief Engineer Rafiqul Islam said, “I have asked to submit the report by tomorrow if possible. I will take action accordingly after receiving the investigation report. ”

Asked for his opinion on the crack after the inspection, he said, "We have already stated our opinion. Now it would not be right to comment during the investigation. I will let you know when I get the report. ”

While inspecting the flyover at noon on October 26, City Mayor M Rezaul Karim and Chittagong City Corporation Chief Engineer Rafiqul Islam saw cracks and commented that the ramp may have construction defects or design defects.
That morning, Mahfuzur Rahman, project director of the Chittagong Development Authority (CDA), the company that built the flyover, said heavy vehicles could crack on the ramps made for light vehicles. However, he claimed to the media that afternoon that there was no 'crack'.

The next day, on October 26, experts from Design Planning and Management (DPM) Consultants Limited and Max Group, a contractor, claimed that there were no cracks in the pillars of the flyover, which appeared to be a 'construction joint'.

Although the ramp is designed for light vehicles, both companies have acknowledged that there is heavy traffic. However, the two government service agencies are blaming each other for not having a 'height barrier' at the beginning of the ramp.

The 1.33 km flyover from Chandgaon Thana area of the port city to Bahaddarhat junction was inaugurated by the Prime Minister in October 2013 at a cost of Taka 106 crore. The construction work started in December 2010. CDA constructed the flyover at its own expense at a cost of Tk 108 crore.

The ramp, built by locals, was launched in December 2016, almost four years later. In December 2019, the CDA handed over the flyover to the City Corporation for maintenance.
Made with Ambuja cement using 3000 BC vedic tech.
 
View attachment 790123
iu


All are disasters waiting to happen...
A country is run by its administrators and a country's constructions and design are run by engineers working in some engineering offices who have the ability to find faults in the design of a structure within their own territory.

Can someone tell me which BD authority is responsible to check/ evaluate the design of piled foundations and superstructures for the expressway?

Note that there is no Construction Ministry whose engineers keep everything under control and force the design contractors to obey the design rules.

But, are their design rules in BD by following AASHTO and other methods? If so, why the structures above are rickety if earthquake lateral loads have been taken into consideration while doing design works?
 
View attachment 790123

A country is run by its administrators and a country's constructions and design are run by engineers working in some engineering offices who have the ability to find faults in the design of a structure within their own territory.

Can someone tell me which BD authority is responsible to check/ evaluate the design of piled foundations and superstructures for the expressway?

Note that there is no Construction Ministry whose engineers keep everything under control and force the design contractors to obey the design rules.

But, are their design rules in BD by following AASHTO and other methods? If so, why the structures above are rickety if earthquake lateral loads have been taken into consideration while doing design works?

RHD or Roads and Highways Dept. is the regulatory body as well as the implementer for interdistrict highways and expressways. I don't think there is any check and balance as far as standards. Shiyaler kasey Murgi dewar moto obostha.

I believe LGED does the same thing for Local Govt. roads (smaller grade roads - not expressways) and they are better paid and more technically apt, but AASHTO compliance is anybody's guess.

Here is RHD and LGED sites:

 
RHD or Roads and Highways Dept. is the regulatory body as well as the implementer for interdistrict highways and expressways. I don't think there is any check and balance as far as standards. Shiyaler kasey Murgi dewar moto obostha.

I believe LGED does the same thing for Local Govt. roads (smaller grade roads - not expressways) and they are better paid and more technically apt, but AASHTO compliance is anybody's guess.
1636192447348.png

By reading the two paragraphs above, I find my guesses were correct that BD govt authorities have not yet created AASHTO or ACI-like standards. These guys from peasant families just have no knowledge about these things.

So, how can you expect the main Contractor to follow rules that do not exist in BD. The foreign Contractors arbitrarily do their own in-house structural design analysis, decide the number and depth of piles, draft the design/ construction drawings, then construct and take away the money.

Without proper standards set by the govt authority, the Safety Factor (SF) matter may be disregarded and the sizes of beams and piers may become smaller because it saves money, but the longevity of structures become shorter even without earthquakes.

The SF of the structures above may have 1.2 instead of a mandatory 1.5. This is dangerous. Even without a strong jolt by earthquake, fatigue due to their continuous use and being exposed to rain, heat, cold and temperature difference, the structures will weaken long before their expected design life.
 
View attachment 790560
By reading the two paragraphs above, I find my guesses were correct that BD govt authorities have not yet created AASHTO or ACI-like standards. These guys from peasant families just have no knowledge about these things.

So, how can you expect the main Contractor to follow rules that do not exist in BD. The foreign Contractors arbitrarily do their own in-house structural design analysis, decide the number and depth of piles, draft the design/ construction drawings, then construct and take away the money.

Without proper standards set by the govt authority, the Safety Factor (SF) matter may be disregarded and the sizes of beams and piers may become smaller because it saves money, but the longevity of structures become shorter even without earthquakes.

The SF of the structures above may have 1.2 instead of a mandatory 1.5. This is dangerous. Even without a strong jolt by earthquake, fatigue due to their continuous use and being exposed to rain, heat, cold and temperature difference, the structures will weaken long before their expected design life.

I guess the contracts are written so builders and contractors have no performance guarantee money deposited in local banks either, and the local baboos approve these contracts in exchange for uthkoch (graft).

This AL slogan of "Charidikey shudhu unnoyon ar unnoyon" (Development wherever you look!) should be changed to "Charidikey shudhu churi ar churi" (Rank Theft wherever you look!)....
 
Cracks due to overloading are supposed to occur first in the horizontal slabs when an excessive Bending Moment is produced on them. But, the picture shows heavy cracks in the Pier. This may happen due to many reasons:

1) higher water-cement ratio in the raw concrete
2) Low quantity of cement per cubic meter of concrete
3) Less amount of top bars in the Pier
4) Existence of structural joints between the Pier and the Girder
5) Lateral pressure due to earthquake, etc.

Point #4 is certainly not desired. Please note the following:

1) Pier construction stops at the desired elevation and the Pier is fitted with a required number of Anchor Holes during construction.
2) Anchor holes usually move away from the center position during construction. So, the positions are rectified as per drawings.
3) A Steel Shoe(s) is placed on top of Piers and is anchored with the Anchor Bolts.
4) The main Girder is placed on top of the Shoes.

With this system, the Shoe will absorb a lateral jolt. The shoe disallows bending moments at the Pier top. It allows the Girder to rotate in the longitudinal direction. So the longitudinal bending moment due to vehicle movements is absorbed.

It also allows the Girders to move horizontally in transverse directions. Two more important points are:

1) Structural joint between the Girder and the Pier (no rebar connection) is not allowed.
2) A Girder can move horizontally during an earthquake because it is placed on a round steel shaft fitted in the Shoe.

So, I found the rickety Dhaka highway to follow the basic rules and the Chittagong flyover did not.

1636254501566.png


@Bilal9
 
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Cracks due to overloading are supposed to occur first in the horizontal slabs because an excessive Bending Moment is produced on them. But, the picture shows heavy cracks in the Pier. This may happen due to many reasons:

1) higher water-cement ratio in the raw concrete
2) Low quantity of cement per cubic meter of concrete
3) Less amount of top bars in the Pier
4) Existence of structural joints between the Pier and the Girder
5) Lateral pressure due to earthquake, etc.

Oint #4 is certainly not desired. Please note the following:

1) Pier construction stops at the desired elevation and the Pier is fitted with a required number of Anchor Holes during construction.
2) Anchor holes usually move away from the center position during construction. So, the positions are rectified as per drawings.
3) A Steel Shoe(s) is placed on top of Piers and is anchored with the Anchor Bolts.
4) The main Girder is placed on top of the Shoes.

With this system, the Shoe will absorb a lateral jolt. The shoe creates no bending moment at the Pier top. The Shoe allows the Girder to rotate in the longitudinal direction. So the longitudinal bending moment due to vehicle movements is absorbed.

And the Shoe allows the Girders to move horizontally in transverse directions.
Two more important points are:

1) No structural joint between the Girder and the Pier (no rebar connection)
is allowed.
2) The Girder can move horizontally during an earthquake because it is placed on a round steel shaft fitted in the Shoe.

View attachment 790855
So, I found the rickety Dhaka highway is following the basic rules and the Chittagong flyover did not.

View attachment 790858

@Bilal9

Excellent analysis @bluesky bhai.

So - I bet whomever designed the Chittagong flyover is completely unqualified then. Probably some diploma engineer that works for the Chittagong Development Authority (CDA).

I hope they put the guy who approved the plans in jail. Ditto for the contractor.

I am surprised there is no additional scrutiny for these designs by some one more qualified in Bangladesh.

And there should definitely be some mechanism to stop trucks from getting on these flyovers by using a horizontal height barrier, which was never installed. I hope they install height barriers now on all flyovers and elevated expressways.

You will need some big accident in order to have these baboos finally squirm in their seats....

Is there a shortcut repair possible (using heavy steel plates bolted to the structure or welded as patches)?

Or is demolishing and rebuilding the column the final solution?
 
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You will need some big accident in order to have these baboos finally squirm in their seats....
Before you put him in jail it is necessary that the govt authorities learn the values of adopting AASHTO and ACI standards design and construct. The engineers working in private companies are supposed to follow these rules, and the rules are set by the govt authorities.

Our people follow the rule of the thumbs. উপরে আল্লায় আছেনা, কোনো ভুলত্রুটি হইলে সে একটা ব্যবস্থা কইরা দিবো। চিন্তার কোনো কারণ তো দেখিনা।

Bloody, peasant society!!
 

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