"Why Joshimath is Sinking: A Civil Engineering Perspective"

The Sinking of Town Joshimath in Uttarakhand: A Civil Engineering Perspective

As a civil engineering student, I have been closely following the reports of Joshimath, a town in India, sinking due to a variety of factors. In this blog post, I want to dive deeper into the technical terms and concepts that are involved in this situation, in order to provide a better understanding of what is happening and why it is so concerning.

Bearing Capacity

One of the main factors contributing to Joshimath's sinking is the low bearing capacity of the landslide debris on which the town was built. 

The bearing capacity of a soil is the maximum load that it can support without experiencing significant settlement or failure.

When a structure is built on a soil with a low bearing capacity, it is more prone to sinking or collapsing, particularly if there are additional loads placed on it, such as those from increased construction or hydroelectric projects.

Gneissic Rocks

The Wadia Institute of Himalayan Geology conducted a survey in 2022 and found that the gneissic rocks in the area around Joshimath are extremely worn-out, have a low cohesive value, and are prone to high pore pressure when saturated with water, particularly during the monsoon season. 

Gneiss is a type of metamorphic rock formed under high pressure and temperature conditions. It is characterized by a banded or foliated texture, with alternating layers of different minerals. 

When gneissic rocks are worn-out, it means that they have been subjected to significant weathering and erosion, which can weaken their overall strength and stability. A low cohesive value means that the rocks have a weak surface attraction and are prone to sliding or crumbling. High pore pressure can occur when water fills the pores or spaces within the rock, causing it to become unstable and prone to failure.

Punctured Aquifer

Environmentalist Ravi Chopra has suggested that the sinking of Joshimath may be related to a punctured aquifer inside the Joshimath mountain area. 

An aquifer is an underground layer of water-bearing permeable rock or sediment that can be tapped to provide a water supply. When an aquifer is punctured, it means that it has been pierced or penetrated, allowing water to leak out. 

In the case of Joshimath, it is reported that the NTPC admitted to "water seepage from a punctured aquifer" inside the tunnel in 2020. This could potentially cause the mountains in the area to gradually collapse, much like a leaking balloon.

In conclusion, the sinking of Joshimath is a complex issue that is being caused by a variety of factors, including the low bearing capacity of the soil, the characteristics of the gneissic rocks in the area, and the potential for a punctured aquifer. In order to address the situation, it will be necessary to halt all construction and hydroelectric projects in the area, relocate the population to a safer location, and revise the town's planning to account for the new variables and shifting geographical conditions.

 This will require a coordinated effort between the government, civil organizations, and military organizations like the Border Roads Organisation (BRO).

I hope you found this blog post informative and that it has helped to clarify some of the technical terms and concepts related to the sinking of Joshimath. 

As a civil engineering student, I have a personal interest in understanding the issues that are impacting our infrastructure and communities. If you have any questions or would like more information on this topic, please don't hesitate to reach out. I am always happy to share my knowledge and insights.

If you would like to show your support and help raise awareness about this important issue, please consider sharing this blog post on your social media platforms. Every little bit helps to bring attention to these types of problems and potentially make a difference in the lives of those affected. 

Thank you for your interest and support. Together, we can make a difference.