HYDERABAD: Stating that the findings in the National Dam Safety Authority (NDSA) report were vague and no evidence or specific details were provided in support of alleged deficiency in construction or quality control and assurances, Afcons-Vijeta-PES-JV, in a recent letter to the Irrigation superintending engineer, Ramagundam, said that remedial measures such as grouting were carried out on Annaram barrage of the Kaleshwaram Lift Irrigation Scheme (KLIS) as per the directions of the Irrigation department.
All remedial measures — polyurethane grouting, ring bunds — were undertaken and carried out under the instructions and supervision of the Irrigation department, Afcons said in its letter. The curtain grouting, upstream grouting, close curtain grouting and other works were carried out as per the instructions of the department, it added.
Regarding curtain grouting and void backfilling under the raft, the contractor carried out the works as instructed by the department in a letter in June 2024.
“Thus, the decision to perform upstream grouting, which is stated to have allegedly altered the secant pile cutoff condition, was of the department, not by the contractor. We complied with all the instructions of the department,” the company said.
It may be recalled that the NDSA in its final report stated that the premature grouting activities irreversibly altered critical sub-surface geotechnical conditions underneath the raft and along secant pile cutoffs, hampering the ability to evaluate the original ground conditions and state of the structures effectively.
Safety of the barrage
With reference to suggestions made by the NDSA, the Afcons said in its letter: “The NDSA vide its report has recommended holistic rehabilitation design, advocating for a comprehensive assessment of health and safety of the Annaram barrage.
This includes detailed assessment of the structural health and safety of the barrage, comprehensive geotechnical studies and advanced geophysical assessments, hydraulic design aided by appropriate hydraulic model studies and structural design through appropriate mathematical modeling software, etc.
For the same, NDSA has suggested the department utilising the services of best institutions/research stations/departments in the country for investigations and rehabilitation design.”
“Therefore, the contractor requests the department to immediately consider engagement of I&CAD designer/qualified specialised agency/design consultant by the department (design being the department’s responsibility) to undertake rehabilitation design as suggested by NDSA,” the contractor said and reiterated that it will provide all necessary assistance in execution of rehabilitation work as per drawing and instruction by the department.