Trenchless Technology

  

Trenchless Technology

         Excavation is a major part of construction in any civil engineering project. However, traditional techniques of excavation have proven to be intrusive, disturbing to the environment, relatively costlier and time consuming by studies over a period of time. It results in excessive air and sound pollution making the day to day life of local residents difficult. We can take the example of Kathmandu, where the locals have been facing this problem for a few years now due to continuous excavation of road for water supply projects, extension of sewer lines and several other projects. Also, it causes the obstruction of road during construction which causes traffic problems. So, traditional methods are seen outdated from every aspect, especially in case of crowded and congested cities for excavation.

             Due to these shortcomings a new technology for excavation, also known as trenchless technology has been rapidly growing into a popular choice across the world for some years now and is proven to be quiet efficient. A recent example of this technology was adopted in Nepal as well. Nepal Electricity Authority (NEA)  has adopted a technology called Horizontal Directional Drilling to put power lines of Kathmandu city underground. The project which is worth around 7.41 billion Nepali Rupees, is being undertaken by Indian firm KEI industries Ltd and can prove to be groundbreaking for advancement of this new technology in Nepal.

                So, what is Trenchless Technology?

            Trenchless technology is the use of different methods, equipment and materials to perform excavation for various purposes such as sewer lines installation, underground laying of electric wires, etc. with minimal disruption to ground activities such as surface traffic, business activities and other activities of people.

             Some Types of Trenchless Technology:

·         Moling: It is generally used to lay pipes. Here, a pneumatically-driven machine known as a mole, forces its way through the soil along the desired path of the pipe.

                                     Image courtesy: INTERNATIONAL SOCIETY FOR TRENCHLESS TECHNOLOGY

·   

 A Horizontal Auger boring: Helical shaft is rotated to excavate soil advancing along the more or less level line as shown in the figure below.

 

                                                      Image courtesy: theconstructor.org

·         Tunneling and micro tunneling: Tunnels can be built employing various methods for excavations.

                                                          Image courtesy: vilkograd.com

·         Horizontal Directional Drilling: It uses horizontal drilling machine, and associated attachments, to accurately drill along the chosen bore path.

                                                             Image courtesy: nsccme.com

 

                            Significance of trenchless technology:

•          Economical: Though initial costs are high, investment is done in necessary equipment and tools, it proves out to be around 50% cheaper than traditional excavation method.
•       Minimized Disturbance: As heavy excavation works are not required it has a lesser impact on overall social, economic and environmental aspects reducing impacts on local personals , business in  the neighborhood, while minimizing sound and noise pollution, etc.
•         Improved Safety: Due to less encounter with underground substances which may be potentially harmful chemicals, unsecured electrical wires, etc. the safety of workers is enhanced to a great extent.
•          Improved Accuracy: With the use of advanced equipment and trained manpower, complex procedures can be carried out with a high standard of accuracy .

 

              Nepal being a developing country is sure to invite major projects based on road, water supply, hydropower, electrical line transmission in the coming days which can be carried out efficiently, economically, safely and sustainably using trenchless technology. It can solve a long running problem of pollution and obstruction in day to day life of citizens that are seen in major cities of the country, whenever any project requiring excavation works are undertaken. It can help to complete the projects quicker and aid greatly to the idea of sustainable development. So, this is something that should be looked upon during any  civil engineering projects in the near future.