Bridge Aqueducts & Metroline

Design and retrofitting of RCC Cross Girders at Metro line Stations

Problem:

• Structural retrofitting of cross girders was required due to a construction error.

Solution:

• 24 cross girders were retrofitted after carrying out design analysis.
• Work involved Grouting and section built-up with micro-concrete
• Application of carbon fiber laminate and wraps as per design

The job was carried out in short time intervals of 2 to 3 hours in late night hours. Traffic management on roads below metro lines was a major challenge. Full scale load testing was done successfully.

Structural repairs of an Under construction Bridge in Purnia Bihar

Problem:

• Dense reinforcement at the bottom of a cast in-situ girder resulted in heavy honey combing or hollow bottom section of the girder after casting.

Solution:

• Loose concrete was removed until only sound concrete is left.
• Hollow section was rebuilt using micro-concrete
• Gap between the two was filled by epoxy grouting
• A layer of CFRP wrap was applied on the girder section that was repaired and applied with protective PU coat

Structural repair and retrofitting of Chehru bridge on NH-01

Problem:

• Structural repair and retrofitting were required after 25 years of commissioning.

Solution:

• Sand blasting, crack filling and epoxy grouting.
• Application of prestressed precured carbon laminate plates along with fiber wrapping work on all 8 spans of 29m each.
• Sanrachana delivered this project successfully in a time of 4.5 months

After completion of the retrofitting work the bridge was successfully tested for IRC Class 70 R loading condition. Chehru bridge on NH-01 part of the original Grand Trunk Road is a vital link between Jalandhar and Phagwara in Punjab

Aquaduct at Tawa Canal Division

Problem:

• It was required to augment the durability aspect of the aquaduct. MP WRD had undertaken strengthening of the piers of Ganjal Aqueduct at Tawa left bank main canal.

Solution:

• Excavation to expose the piers
• Polymer plaster for section built-up
• Application of 22,000 sqm of carbon fiber wraps in two layers, plastering and painting

Problem:

• Central balanced cantilever of 110 m span was showing major distresses

Solution:

• Conventional epoxy grouting was applied along with epoxy mortar repairs
• External post tensioning was used to counteract the large forces across cantilevered portion
• Application of high modulus carbon fiber laminates and carbon fiber wrapping as per design

The bridge connects Mumbai and Gujarat, making it an essential link in NH8. Apart from Sanrachana, experts like IIT Bombay, Ramboll, SMC and IRB were involved with NHAI on this project.