Jaspreet Singh, V. Srinivasa Raghavan
Abstract: This paper chiefly confronts the major complications during multi-level basement / deep foundation construction projects in Delhi. Few of the problems are specifically discussed for Delhi; whereas others are ubiquitous. The major realm of concern are presented here: inadequate dewatering procedure; improper or inadequate soil nailing and shotcreting; poor workmanship in steel placing and binding; improper disposal of anchor slurry and muck; excessive water pressure. Lack of proper monitoring / leniency in monitoring of water table attributed to collapse of earth brim. Improper or inadequate soil nailing and shotcreting contributed to deposition of soil to foundation thereby adding to increase in deposition of muck. Inadequate PCC thickness led to collapse of PCC and creation of large pits thereby increasing inconvenience in muck clearing and causing poor workmanship in steel placement and binding. Failure to proper marking of steel bars in stacks after their cutting and bending can also be a major cause for poor workmanship in steel placement. In this paper; we present illustration of such complication during construction in Delhi and suggest preventive methods. Several of the deficiencies explained in each problem area could easily have been avoided by simply adopting stricter monitoring procedures; quality measures and by enforcing the specification infield practice. Prequalified foundation contractors should have adequate knowledge of soil conditions and behavior and water table and should be safety-conscious.
Keywords: Dewatering complications, Multi-level foundation, cost risk, soil settlement, high-rise buildings, muck problems