Construction Progress in Main Civil Works - Headworks
The Main Civil Works Contract was awarded to Zhejiang First Hydro and Power Construction Group Co. Ltd., Zhejiang, China on April 12, 2018. The Contractor started the mobilization of resources to the construction site in July 2018. The construction of main civil works started from March 2019 from headworks region. The initial excavation for the upstream floodwall, the intake and the gravel trap were commenced from March 2019 which was followed by temporary river diversion works for the construction of the cofferdam. Before the lockdown in Nepal (till February) about 67% of concrete works at Intake area were completed and accomplished concreting at floodwall and Undersluice were about 17% and 54%, respectively. Until the outbreak of COVID-19, the construction progress was smooth and as per the schedule.
The pandemic situation due to outbreak of COVID-19 in late December 2019 was a major challenge in the work progress at site. For effective control of the pandemic, China locked down its territory from January 23, 2020. Since the Main Civil Contractor of the Project is a Chinese company (Zhejiang First Hydro), the machineries, accessories for repair and maintenance as well as various construction equipment and materials could not be imported from China by the Contractor since January and thus the Project was affected much before the Government of Nepal took measures to restrict the spread of virus in the country. The nationwide lockdown effective from March 24, 2020 in Nepal further caused a severe restriction in materials transport, availability of local human resources and overall inconvenience for smooth working in the Project. The situation was further exacerbated by the fact that some Chinese workers of Zhejiang First Hydro, who had gone home to celebrate the Spring Festival, could not return from China causing shortage of skilled human resource at site.
The Nepal Government officially announced the nationwide lockdown effective from March 24, 2020 and all public and private transportation including the business activities were completely halted. The lockdown posed a serious challenge to the Project because available stock of construction materials at site when the lockdown was announced was extremely low to meet the huge requirement to fulfill the dry season plan. To make the situation worse, the monsoon was approaching very fast.
The Engineer issued the preventive approach letter dated April 04, 2020 for the construction of significant structures like undersluice and u/s floodwall and instructed the Contractor to achieve the minimum required construction by the end of April 2020. The Employer arranged vehicle passes at the request of Contractor for the transportation of construction materials initially from the District Administration and subsequently from the Ministry of Home Affairs. The first pass was obtained from the CDO Office on March 26, 2020 for local transportation for food supplies and other essentials. Finally, the Employer could obtain road permits for 25 various kinds of vehicles.
Thanks to these efforts against all odds, even during the harsh lockdown continuous supply of significant quantities of various construction materials like rebar, cement, explosives, and diesel as well as food items was ensured. At one stage it seemed improbable to transport such a large quantity of construction materials to the site. As a result, even during the period of extreme lockdown, the Contractor was not forced to completely shut down the construction works and a significant progress, much beyond the minimum required, has been made in areas as instructed by the Engineer, especially at the Headworks. Obviously the progress is still behind the schedule and cannot be considered fully satisfactory, but given the difficulties created by a global pandemic, commendable efforts by the Employer and the Contractors have certainly prevented a significant loss of structural and financial damages.
Currently almost all Chinese workers have gone home for vaccination. Until their return the Main Civil Contractor has been carrying out tunnel excavation from the outlet and excavation and concreting of Powerhouse components through Nepali subcontractors. Certainly the dry season plan of construction has been affected, but the delay is manageable with an additional effort at a later stage.
Despite difficulties mentioned above, till date almost 99% of concrete works at Undersluice, 97% at intake and 88% at U/s floodwall has been completed. Further, D/s right floodwall and cutoff-wall have been already constructed. Given the countless hurdles caused by the pandemic-related policy restrictions and panic reactions at the community level, this is a highly satisfactory achievement. Two more months will be required to complete all remaining activities on these fronts at the undersluice after re-coffering, which will be done when the discharge level in the river begins to recede. Further, the excavation works on the weir and stilling basin along with powerhouse and tailrace floodwall are ongoing.