Foundations Failures of Bridges and Geotechnical Investigations

In the present paper two cases of foundation failures due to which the complete bridge structure have failed are reported. The 93m long Palakmati high level brick masonry arch bridge on Hoshangabad - Piparia Road was constructed in year 1910. This bridge has shallow well brick masonry foundation with brick masonry wall type piers. Foundations of piers were on two circular shallow independent wells. The wells are resting on yellow soil. During floods of 1989, the pier No.3 sunk. This brought down 5 spans. Two well foundations were up-rooted. Cracks were developed in other arches also. The 90.5m long submersible R.C.C. trough slab type Mand bridge in 60/8 km on Ambikapur-Pathalgaon Road of 5. 5m width was constructed in the year 1945-46. The bridge has open foundation resting on rock whereas superstructure consist of R.C.C. portal framed structure. The foundation of first pier towards Ambikapur side sunk by about 0. 4m in August 1991. Due to this abrupt settlement the abutment and all the three piers have developed through cracks below the supports and severe cracks in all spans. Geotechnical investigations are carried out in these two cases and remedial measures are suggested for reconstruction of new bridges