Geo-Textile Sand Container Mattresses (GSCM) Lining for Temporary River Diversion Channels

摘要

HCC (Hindustan Construction Co. Ltd) has been a leading construction industry in India since 1926. For about 80 years, HCC has led the way in engineering construction. The company has made landmark contributions in the field of Power, Water, Transportation, Tunneling, Environmental engineering and Industrial Construction. HCC exceeds in undertaking all types of large Civil engineering and Infrastructure projects, and has the capability in Engineering and design Research and development Procurement Construction and commissioning Operation and maintenance Project management HCC has innovated new method of lining of temporary river diversion channels. Temporary river diversion work is a very important part of all river valley projects. The river is required to be diverted so as to facilitate the construction of the hydraulic structure, like dam or barrage, across the valley in the course of project execution. In most of the projects, diversion through an open channel is the easiest and most economical option. The diversion channels are designed and constructed for a functional period of 1 to 3 years depending upon the type and size of the project. These channels are required to carry monsoon and non-monsoon river discharge safely without hampering or endangering construction activity. Construction of diversion channels is carried out in non-monsoon lean flow period. Large quantity of excavation is required to be done which consumes major part of available time leaving very short time period for execution of lining work. Traditionally, diversion channels are lined with (rip rap) boulders, 600 to 800 mm thick, in concrete ribs. Well graded sand filter of thickness varying from 300 to 600 mm is provided below the boulders. Collection of large quantity of boulders, its transportation to the site and stacking in a very short time frame involves unavoidable delays and higher costs. In some cases, like the one faced by HCC at Teesta hydro-electric project, the unavailability of the boulders itself was the bottleneck in lining constructing. Considering the constraints associated with this traditional design, a need was felt to develop an economical, speedy and reliable method of lining. Geo-Textile Sand Container Mattresses (GSCM) Lining was conceived, designed and installed for the Teesta IV Hydro electric project by HCC. The paper discusses the design approach, adoption of design for different soil conditions, construction methodology, performance review (over a short time period) and economics of the GSCM lining.