Built in 1540 AD, the Cabo Fort is the official residence of the Governor of Goa.
The fort is located on Cabo Hill at a height of 40 m above the sea. It is a two-storied monumental structure constructed with 0.7 m thick walls comprising of laterite blocks in mud mortar.
The hill slope was reported to have undergone gradual distress due to natural processes over several decades with cracks appearing on the asphalted pavement in front of the Chapel and on the floor of the verandah. The parapet wall constructed around the edge of the steep slope adjacent to the fort had also developed cracks at many places indicative of horizontal and lateral movement.
Parts of the slope were stabilized by using pre-stressed cables to tie up fractured media and by installing shear interceptors using micro piles. Vertical sand piles were also installed to release possible ground water pressure. The toe of the slope was stabilized with retaining walls.
To monitor the distressed unstable slopes of the Cabo Hill, GSI recommended field monitoring through instrumentation. The instrumentation scheme included monitoring of slope movement, settlement, water pressure and ground cracks.
Encardio-rite was entrusted with the task of monitoring and instrumentation. While implementing the instrumentation system, steps had to be taken to ensure no structural damage was incurred.
Strengthening measures were devised for the slope foundation and the Fort’s structure, using Encardio-rite instruments.
Encardio-rite’s instrumentation is still providing data online to the relevant authorities. The scope of work included the supply of instruments, installation, manual and automatic monitoring and setting up a web data management system.
Instruments used included an in-place inclinometer, borehole extensometer, piezometers, crack meters, joint meters and automatic data loggers. An experienced and proficient instrumentation and monitoring team provided installation and commissioning services. A combined report for both manual and online data was provided on a monthly basis. Monitoring reports included interpretations of variations observed in the data, mentioning the factors likely to affect the behavior.