RVNL Tunnel Project - Obulavaripalle to Venkatachalam
New Broad Gauge Railway Line from Obulavaripalle to Venkatachalam -Construction of Roadbed from KM 17/0 to 35/0 including construction of two Tunnels from chainage 18660 to 19600 and chainage 23370 to 29990 with ballastless track and earthwork in Formation, Major and Minor Bridges covering Kadapa and Nellore Districts of Andhra Pradesh in South Central Railway, India
The project, when completed, will provide rail connectivity to the gateway port at Krishnapatnam on the east coast. It will significantly reduce the haulage distance to the Support
The alignment crosses the Eastern Ghats over the Rapur-Vellikonda range. It is mostly
The alignment crossess the Eastern Ghats over the Rapur-Vellikonda range. It is Mostly densely forested ghat section. The contract includes construction of the entire roadbed of 18 KMs length, over the entire length. Apart from the earthwork in formation in embankment and in cutting, the contract includes two tunnels aggregating to a total length of 7.56 KMs
The most important part of the contract are two railway tunnels at chainages 18.660 to 19.600 (length 0.94 KM) and 23.370 to 29.990 (length 6.62 KMs), The entire length of tunnels is be constructed by the New Austrian Tunnelling Method (NATM), using a cyclic sequence of excavation followed by immediate installation of a primary support consisting rock bolts and reinforced shotcrete(outer lining), and delayed installation of a secondary lining consisting of cast-in-situ concrete (inner lining). The slopes of deep cuttings and approaches to tunnels are also to be stabilized and protected by similar protection methods.