Bangabandhu Jamuna Multipurpose Bridge


Problem identification using analytical and testing tools for Bangabandhu Jamuna Multipurpose Bridge
Worked as Consultant to provide technical services to Bangladesh Bridge Authority, Government of the People’s Republic of Bangladesh during March 2006-June 2006. The causes of extensive cracking of the segmental pre-stressed concrete box girders of the Bangabandhu Jamuna Multipurpose Bridge were identified. The bridge has 48 spans, each having an approximate length of 100m. The segments of the bridge pre-stressed both in longitudinal and in transverse direction. In the analytical investigation, three-dimensional nonlinear model of the bridge was developed through extensive use of finite elements. The Jamuna Multipurpose Bridge, when constructed stood as the 11th longest bridge of the world and the longest in Bangladesh as of today. The role of this bridge in the economy of Bangladesh is vital as it provides strategic links for road, rail, electricity and gas transmission between northern and southern part of the country by crossing the Jamuna River, one of the widest rivers of the world. The hydraulic properties of the river and sediments are quite difficult to predict.

Repair and retrofitting of Bangabandhu Jamuna Multipurpose Bridge
As a member of the Expert Committee, now serving the Bangladesh Bridge Authority, Government of the Peoples’ Republic of Bangladesh by giving technical advices on design and implementation of the repair and retrofitting methodology for the bridge deck and replacement of expansion joints. In this process, analytical results for the box girders of the bridge are vital for assessing the as-built present capacity at critical load combinations and thereby calculating the strengthening requirements. The measures undertaken for repair and strengthening of the deck included extensive use of fibre reinforced polymer strips, thermal insulation and stone mastic asphalt wearing course in the form of laminated composites.

Health Monitoring of Bangabandhu Jamuna Multipurpose Bridge
Working as the Team Leader to monitor the post-repair health condition of the bridge using vibration sensors. Temperature and Humidity Data logging on the top and beneath the deck surfaces are also being done.

Top Supervision Services
Dr. Saiful Amin is providing Top Supervision Services to the Bangladesh Bridge Authority for the ongoing Repair and Strengthening of the Bangabandhu Jamuna Bridge. The Bridge Deck is now being repaired and retrofitted with FRP and the Expansion Joints are getting replaced.

Repair of the Bearings, Joints of the Meghna & the Meghna-Gumuti Bridges and stabilizing the foundation from river bed scour


Bridge superstructures are usually designed to accommodate thermal strains due to ambient temperature gradients and deformations due to live loads all extreme possible combinations. Bridge bearings have to transfer forces from the superstructure to the substructure whereas expansion joints allow all movements in the designed directions. Expansion joints should provide a smooth transition at the deck level for vehicle movement, avoid noise/vibration emission as far as possible and withstand all mechanical actions and chemical attacks (de-icing salts, if any) for the designed durability. The design should have the provision for simple replacement of all wearing parts and the entire expansion joints. Dr. Amin extensively studied the subject and conducted extensive research in UG and PG levels to develop local expertise for quality control and quality assurance of rubber bearings and expansion joints. Maintenance, durability, life cycle analysis, replacement techniques of joints and bearings are also the points interests to address.

In this context, Dr. Amin acted as Team Leader of the BRTC, BUET Team to provide technical services to the Roads and Highways Department, Government of the Peoples’ Republic of Bangladesh for the maintenance and remedial measures of the Meghna and the Meghna-Gumuti Bridges on National Highway N1. These bridges are PC box girder bridges having central hinge and expansion joints to reach 87m span. The expansion joints placed at the hinge locations need to accommodate longitudinal movements occurring not only due to creep, shrinkage and temperature effects but also the longitudinal sways induced by the rotation of piers. Ageing of the bridge can induce reduction of pier stiffness due to fatigue (governed by past loading history) whereas plastic deformations occurred due to creep need also to be accounted. Assessment of expansion demand in an old bridge of this type is critically encountered in maintenance and rehabilitation works. Dr. Saiful Amin having specialization in structural mechanics, constitutive modelling with finite strain theories, experimental observation of constitutive behaviour and finite element implementation of constitutive models gave his expert input in this project as the Team Leader to make emergency repair and final replacement of the joints and bearings of these two bridges. Calculation of expansion-contraction demands and verification was vital. In this course, efforts were made to arrive at a realistic FE model of the bridge including the hinges to adequately take the nonlinear load dependent behavior of the pot bearings into account. Simulations are conducted on different functionality levels of the hinges under standard and overloading situations. Utilization of vibration monitoring data and implementation of eigensystem realization algorithm were important for dynamic characterization of this range of bridges. In the Meghna Bridge, the current displacements were found to be coupled with river bed scour problem. This fixing the pier foundations and protecting the same from scour was the other dimension of this work.



QA & QC of Rubberlike Materials


Dr. Saiful Amin is entrusted for testing rubber and rubberlike materials in the Department of Civil Engineering, BUET via BRTC, BUET. To deliver the service, he is equipping the Structural Mechanics Laboratory of the department to prepare the samples and to test the soft polymeric materials in including rubber for QA & QC purposes following standard procedures. These test reports are vital for QA & QC of bridge bearings for flyovers and bridges in the country.

Investigation of the Collapse of Bohodderhat Flyover during Construction


Appointed by the Government of the Peoples’ Republic of Bangladesh, Dr. Saiful Amin worked as the Member Secretary of the National Committee to assess the quality of construction of the ill-fated 1.33 km long Bohodderhat flyover, Chittagong where three girders collapsed during construction causing severe injury to life and property and assist the concerned ministry in taking decisions. In this context, the committee looked into details of the quality of construction materials used, quality of the finished construction elements, quality of equipment and arrangement used for construction, quality of construction methodology and sequence adopted and also the quality of safety practice exercised during construction to derive the conclusions about the incident and propose the next steps to be taken by the Government.

Assessment of Construction Defects of PC Bridges


Engaged by the Roads and Highways Department, Government of the Peoples’ Republic of Bangladesh, Dr. Saiful Amin worked as the Team Leader to check the structural adequacy of a 43m PC girder in 348.12m long PC girder bridge over the Shangkha River at the 8th km of Fultoli-Kanchana-Khoderhat Road under Dohazari Road Division, Chittagong. The Girder 2C of the 2nd Span of the bridge reportedly got laterally deflected about 10 days after application of prestress and subsequent grouting. The BRTC, BUET had to check the structural adequacy of the curved girder (2C) for the design loads. Total Station Survey of the girders in question was used to ascertain the sectional capacities. On site measurement of natural frequency of the girders to make a comparison of the order of stiffness between the acceptable girders and the girder with geometric deformations. A critical comparison between the theoretical and field measurement values was made.

Further services were given also for the bridges over the Mahananda and the Meghna (in Narshingdi) for similar problems.



Checking the Design of Long Span Steel Truss Bridges


Appointed by the Roads and Highways Department, Government of the Peoples’ Republic of Bangladesh, Dr. Saiful Amin acted as Team Leader to check the structural adequacy and erection methodology of a 100m span steel bridge over the Modhumoti River and a 115m span steel bridge over the Surma River.

Pedestrian Bridge over the Crescent Lake, National Parliament Building of Bangladesh


Checking the structural design adequacy of a suspended-span arch-supported pedestrian bridge constructed over the Crescent Lake near the National Parliament Building in Dhaka, Bangladesh. The bridge facilitates the movement of pedestrians to the nearby mausoleum of Shaheed Ziaur Rahman, former president of Bangladesh and adjacent Chandrima Garden. The bridge having a suspended span of 56.1m allows the movement of pedestrians over a steel framed tempered glass deck. In addition to the static analysis, the fundamental vibration modes of the arch-deck system was to be examined through dynamic analysis to restrict the pedestrian-induced vibration within acceptable limit in accordance with the recent version of British Code (BS 5400, amended vide BD 37/01 on August 2001). The revision of the British Code took place in 2001 following the observation of serviceability problem due to pedestrian movement induced vibration in the Millennium Bridge, London, UK and Toda Bridge in Tokyo, Japan. The bridge was first of its kind constructed in Bangladesh.