Construction, planning and time management of underground excavation by modern construction technologies

Infrastructure development is the need of the hour and society needs it for survival. Underground space is vital for sustained growth and engineers play the key role in construction, planning and timely development of it. The critical activity for any underground project is the “Underground excavation” whether it pertains to hydropower, irrigation, urban transport, rail road, sewage disposal, oil/gas storage or strategic installations. If the excavation of an underground project is timely executed, by all probabilities, it should finish on time. Many projects all over the world have been abnormally delayed with exorbitant time and cost over-runs for improper planning, investigation and methodology adopted during excavation. Therefore, the time management is very important and methodology adopted should be carefully chosen as option to review it in case of geological surprises is limited especially in Himalayan Geology. Quality of excavation also matters. The progress of balance activities like final lining is affected if excavation is not done properly. In hydropower generation or irrigation projects, it is the technical parameters which decide requirement of the underground space. In urban development projects, it is the space constraint over the ground which forces the society to go underground. In Railway or road projects, the ruling gradient, the bridge locations and connectivity to the villages/towns is the criteria for selection of the alignment while it passes through the tunnels. The crossing points or railway stations are also accommodated underground as per the operational needs. For the utility tunnels like sewage disposal, oil/gas storage, pipelines etc. the entry and exit points decide the criteria to go underground. The utilization of underground space in urban development or hilly terrain solves many problems and is environment friendly. The maintenance, operational and security costs of being underground are less though despite high construction costs.