Analysis of support system for deep excavation

Abstract

Rapid growth of urbanisation, industralisation and population in developed, developing and under developed countries of metropolitan and cosmopolitan cities resulted in great constraints on the utilisation of land space. This has provoked the civil engineer to prefer underground space for the construction of various infrastructure facilities such as tunnels, basements, underground utilities etc. Underground deep excavation is always posing a great challenge to the engineer not only to provide a stable underground system but also on the safety measures of adjoining structures both in pre-construction and post-construction period of execution. Array of evidences are well documented in literatures on the devastating failures during execution of underground construction and also in many instances over the post construction catastrophes. Eventhough the advanced underground construction technologies such as diaphragm wall, contiguous pile and soil nailing have surpassed most of the prevailing difficulties of conventional underground support system viz. braced excavations, but still there is a challenging task for an engineer to overcome the problems encountered during execution for a safe design and also onto the safeguarding adjoining structures, utilities and livelihood of mankind. Documents available in the literatures are very limited on the real time monitoring of underground excavation systems, besides the huge vacuum in delineating the various factors responsible for a safe design and execution of underground support system. In the context of above, the present investigation focuses on the real time analysis, design and execution of two challenging underground construction sites, in which the study area-1 was located at Noida, Uttar Pradesh, India with 24000 m2 area for the proposed construction of G + 13 storied complex with 3 basements and the other study area-2 located at Bengaluru, with 3781 m2 area and 13792 m2 for Tower 6 and Tower 7 and 8 respectively for the proposed construction of G + 10 storied complex