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EPISODE 21: REPORT ON DWARKA EXPRESSWAY GIRDER COLLAPSED  Dwarka Expressway way, Package 3 bridge collapse 28/03/2021 Contractor: LNT,   Engineer: AECOM, CEG Video:  https://www.youtube.com/watch?v=mKB4fr15IEI As per VK Raina Report: Inspection of the Collapsed Spans of decks of Dwarka Gurgaon Bridge one almost fully prestressed and the other ready on hooks about to be prestressed.  Its observed that the Concrete surface at the bottoms of 2 segments was  of very  poor quality and fully honey combed, which got progressively Crushed in a matter of a  minutes. The soffit commenced crushing, progressively reducing the effective compression  section  area that in turn commenced  folding (upwards) , cracking open the top of top slab in Flexural Tension and the speeding and continuous reduction of effective section progressively Crushed the soffit,  this 1st Plastic Hinge would  Rotate fast enough not allowing the 2nd distr...

 EPISODE 20 SAMRUDDHI EXPRESSWAY VUP COLLAPSED Place  Maharashtra's  Samruddhi Expressway,  (Nagpur-Mumbai Super Communication Expressway) Package -3 Date of Incident: 7/1/2021 Fatality: Officially No Contractor : NCC Reason:  VUP collapsed due to over dumping of green concrete concentrated to a portion over the slab, which leaded to load concentration over a point, as due to which the ground support system failed to carry the load, eventually lead to collapse.

 EPISODE 19 GARUDA VARADHI FLYOVER GROUND SUPPORTING FRAME COLLAPSED Date of Incident: 25/1/2021 Contractor: AFCONS Fatalities  - Officially NO About the Incident: Usually due to some site constraints, some spans will be casted with Ground Support System where LG Launching is not possible,  In the Incident, there was a down Gradient from the pier to pier levels, even they used the standard Ground Support System which is normally used in Segment/Viaduct Construction. Due to improper interlocking with the  end tower with pier might be the reason of the Span Collapse. Video of the Incident All Episodes of Engineering Lessons

  MAHA METRO MACHINARY COLLAPSED Place of the Incident : Maha Metro, Pune Metro Project  Date of the incident: Jan 2019 No Fatal Reports The incident took place as the machine operator could not gauge the sogginess of the soil that caved in. This happened during underground utility checking by the 30 foot piling rig.  which narrowly misses two key flyovers in the area. The site team missed to place the machine on firm ground, which caved during lifting heavy loads. In case of Accidents in working place a fire engine is mandatory to rescue them. But the officials did not ensure the presence of a fire engines. Negligence  is the main reason for the incident. How to avoid this kind of Incidents? There are a range of risks associated with crane operation; Crane pads made of fabricated steel are adopted to distribute the high loading pressure of the crawler crane. The interaction between the crane pad and soil is complicated, and depends on the pad stiffness and...

  Driverless Train of Delhi Metro's Magenta Line crashes into wall Incident date: Dec 2017 Location:  Delhi Metro's Magenta line, Kalindi Kunj Metro Station. Fatality  : No Driverless train of Delhi Metro's Magenta line crashed into a wall of Kalindi Kunj metro station. The Kalkaji -Botanical Garden metro line,  the incident happened within the gated boundary of the station.  Delhi Metro's new generation trains that can be maneuvered without drivers are going to run on this route. Movement of these driverless trains would be facilitated by advanced Communication Based Train Control (CBTC) signaling technology. Initially it is planned to operated by drivers for the initial couple of years. 12.64 km Magenta line was given the necessary safety approvals by Commissioner for Metro Rail Safety (CMRS). A trial train was moved from the workshop without testing the brake system as a result of which, while the train was moving up the ramp for washing, it ro...

WHALE CATCHES DUTCH METRO TRAIN AFTER DEADLY CRASH  Date of the Incident:  2 November 2020 Place :  De Akkers station in Spijkenisse, Netherlands Metro train in Spijkenisse, near the city of Rotterdam, Netherlands crashed through a barrier at the end of the tracks. Instead of plummeting into the water below, the train was caught by a sculpture of a whale's tail.  Several meters above the ground, the train was left perched upon one of two tail fins. The sculpture was built around 20 years ago in a park underneath the raised metro  by artist Maarten Struijs , its name a deliberate play on the fact that it is a “tail track” at the end of the line. Experts said it was unclear why the train had not been stopped by automatic buffers at the end of the track. Apparently something went wrong technically, possibly combined with human error. Surprisingly the sculpture built of plastic have saved the train from falling down, even after 20 years the sculpture made of pl...

  EFFECT OF SKEW ANGLES IN BRIDGES This Article is a compilation of the below Technical Papers, only the Essence of the Papers are provided here for quick grab in this section, detail report is attached below. A Bridge built obliquely between the Supporting Spans are called as Skew Bridge. The angle between the normal to the center line of the bridge and the center line of the abutment is known as Skew Angle. Skew bridges are built where geometry cannot accommodate straight bridge. Alignment should be straight to facilitate high speed and safety requirements of the traffic, this resulted in increase in number of skew bridges. Study 1: This study comprises of Seismic analysis of Box & T Girder Bridges using Response Spectrum Method performed using SAP2000 varying skew angles of the Bridges. Responses of the Substructure, Girders and Deck are studied. An attempt was made to determine skew angle up to which skew bridges have comparable characteristics with straight bridges and al...

 DESIGN FORCES IN METRO BRIDGES This Article is a compilation of the below Technical Papers, only the Essence of the Papers are provided here for quick grab in this section, detail report is attached below. I Girder of span 25m & Box girder of span 40m of metro bridge were considered. Analysis of substructure and superstructure for all static and dynamic loads as per various code and then a comparative study has been done between design forces. IRS Code, EURO Code, &  California high speed rail authority guidelines are used for comparative Codal  References. IRS: CBC suggests higher partial safety factors for dead  load, SIDL and live load in load combinations. Therefore,  moment, shear force calculated as per IRS: CBC at  superstructure are larger as compared to Euro-code and  California high speed rail authority guidelines. Seismic forces calculated on the pier as per IRS - RDSO  guidelines for seismic desig...

  This Article is a compilation of the below Technical Papers, only the Essence of the Papers are provided here for quick grab in this section, detail report is attached below. Generally, for Bridge Super Structure we would construct Box Girder, I/T Girders, Void Beam, etc... So, we require a better understanding of Super Structure Section which best suited for a particular Spans, cost wise & Constructability point of views.   Software used: CSI Bridge   FEM method is economical than the one-dimensional analysis.   Box girder is found to be Costlier for 16.3 m Span whereas for 31 m span the box girder is economical. Box girder are more suitable in terms of stability and economy as compared to T beam girder bridge superstructure. For longer spans the depth of T-beam Girder increases drastically which makes it uneconomical. Therefore, for higher spans more than 25m the Box Girder is always suitable due to its higher torsional rigidity. For lesser spans I ...

LG Collapsed in WDFCC Project - CTP 16       Disclaimer: This post intension is showcase the Engineering Lessons we  can learn from these kind of Incidents, so that the same incident does not gets repeated in our society, Its does not have any intension to devalue the LG Manufacturer,  Contractor.  or the Concern Project. Dedicated Freight Corridor Corporation of India Limited (DFCCIL) is a Public Sector Undertaking (PSU) corporation run by the Government of India's Ministry of Railways to undertake planning, development, and mobilization of financial resources and construction, maintenance and operation of the "Dedicated Freight Corridors" (DFC).        WDFCC CTP -16 was one of the stretch in which the incident  happened. Portal Piers where used as Sub structure & Portal Beams where used for connecting the twin piers. 4 Girder System was used as Super Structure with full span erection methodology. ...