Beneath Nepal’s surface: Tapping into the potential of underground spaces

The utilization of underground space has emerged as a crucial aspect of modern urban development, offering innovative solutions to address the challenges of population growth, urbanization, and infrastructure demands. This essay explores the global practices and prospects of underground space utilization, with a specific focus on Nepal's unique context and potential.

Underground space in construction

The utilization of underground space encompasses a wide range of construction methods and techniques, each tailored to specific project requirements and geological conditions. Open excavation, involving cutting the ground deeper than the existing ground level to create basements, trenches, or open pits, is a common method used for various infrastructure installations. Conversely, fully underground techniques entail excavating space within bedrock or soil cover to construct structures like caverns or tunnels. These methods have evolved, with advancements in technology and engineering enabling more efficient and cost-effective construction processes.

The utilization of underground space is multifaceted, encompassing various functions such as transportation, storage, shelter and utilities. Open-cut methods, including open-pit mining and trench systems, are often employed for infrastructure installations such as water and drainage pipes, cable ducts, and utility networks. These methods offer advantages in terms of cost-effectiveness, ease of construction and minimal disruption to surface activities. Whereas tunneling involves creating underground passages through rock and soil formations, serving as vital transportation arteries and facilitating the movement of water, goods and people between different regions.

Pros and cons

Underground space utilization offers myriad benefits, including land conservation, enhanced environmental sustainability, and improved infrastructure resilience. By relocating infrastructure and utilities underground, cities can preserve valuable surface land for parks and green spaces, thereby enhancing the quality of urban life and promoting environmental sustainability. Moreover, underground facilities protect against natural disasters and extreme weather events, ensuring the safety of critical infrastructure and inhabitants. Additionally, underground transportation systems offer cleaner and more efficient alternatives to surface roads, reducing traffic congestion, air pollution and greenhouse gas emissions. These advantages contribute to a more sustainable and resilient built environment, supporting long-term urban development and growth.

However, despite its numerous benefits, underground space utilization also presents challenges and drawbacks that must be addressed. One significant challenge is the high initial cost associated with underground construction projects, including excavation, reinforcement and structural support systems. Geological uncertainties and risks, such as ground subsidence and water ingress, can lead to delays, cost overruns and safety hazards. Additionally, public opposition and regulatory hurdles may arise due to concerns about safety, environmental impact and community disruption. Robust maintenance and monitoring programs are required to ensure the long-term reliability and safety of underground facilities, posing logistical and financial challenges for project developers and operators. Despite these challenges, with proper planning and execution, underground space utilization can play a crucial role in shaping sustainable and resilient cities for the future.

Global case studies

Global case studies showcase the diverse applications and success stories of underground space utilization, offering valuable insights and lessons for urban planners and policymakers worldwide. One prominent example is the Gotthard Base Tunnel in Switzerland, the world’s longest railway and deepest traffic tunnel, spanning over 57 kilometers beneath the Swiss Alps. This groundbreaking project revolutionized transportation infrastructure, significantly reducing travel times and enhancing connectivity across Europe. The Laerdal Tunnel in Norway, with its impressive length of 24.5 kilometers, exemplifies the effective use of underground space to overcome geographical barriers and optimize transport routes.

In densely-populated Asian cities like Tokyo and Shanghai, underground space has become a vital component of urban development strategies. Japan’s extensive subway network, comprising approximately 1.6m kilometers of tunnels, underscores the importance of underground transportation in alleviating congestion and promoting sustainable mobility. China's rapid urbanization has spurred the construction of utility tunnels in major cities, providing essential services while minimizing surface disruption and environmental impact.

European cities like Paris and Stockholm have embraced underground space utilization to preserve historical heritage and address modern urban challenges. The Paris Underground Road, an innovative double-deck tunnel system, effectively manages traffic flow while preserving the city's architectural integrity. In Stockholm, the Swedish Royal Library and Le Grand Louvre Museum demonstrate how underground facilities can seamlessly integrate with surface structures, optimizing space utilization and enhancing cultural heritage preservation.

Tunneling situation in Nepal

Transitioning from global case studies to the local context, Nepal’s rich history of tunneling and underground construction highlights the country’s potential for leveraging underground space in various sectors. From ancient irrigation tunnels in Palpa to modern hydropower projects like the Khimti Hydroelectric Power Plant, Nepal has a legacy of harnessing its rugged terrain for infrastructure development. Recent initiatives such as the Nagdhunga-Naubise underground tunnel road and the Melamchi Diversion Scheme underscore Nepal’s commitment to modernizing its transportation and water management systems through underground infrastructure.

By studying these global and local case studies, urban planners and policymakers in Nepal can gain valuable insights into the diverse applications and benefits of underground space utilization. From enhancing transportation networks and preserving cultural heritage to mitigating environmental impact and promoting sustainable development, underground infrastructure offers a versatile and effective solution to the complex challenges facing modern cities.

Nepal is currently witnessing a surge in tunneling projects across various sectors, showcasing a strategic shift toward subterranean solutions to address pressing societal needs. These initiatives encompass a wide spectrum, from the Melamchi Diversion Scheme, designed to enhance water security by channeling 170m liters per day from the Melamchi River to the Kathmandu Valley through a 26-kilometer tunnel network, to the Tarai Madhes Fast Track project, aimed at improving connectivity with a 6.5-kilometer tunnel road section. Additionally, infrastructure initiatives like the Nagdhunga-Naubise underground tunnel road, spanning 2.68 kilometers, promise to alleviate traffic congestion and enhance road connectivity between Kathmandu and the western region of Nepal.

Furthermore, Nepal’s tunneling endeavors extend to the hydropower sector, with projects such as the Khimti-I Hydropower Plant featuring tunnels of significant lengths. Ongoing feasibility studies for road and railway tunnels underscore Nepal's commitment to exploring innovative solutions for connectivity and economic growth. As Nepal continues its infrastructural development journey, the strategic use of tunneling technology holds immense promise for overcoming key challenges and unlocking new avenues for progress, contributing to a more resilient and prosperous future.

Challenges for Nepal

In Nepal, harnessing underground space for infrastructure presents multifaceted challenges, stemming from the country’s diverse geological landscape. The Himalayan region is marked by complex geological conditions, including varied rock types, discontinuities and high groundwater levels, complicating tunneling and excavation efforts. These geological uncertainties lead to discrepancies between anticipated and actual instabilities during construction, highlighting the need for comprehensive geological surveys and risk assessments to inform project planning and mitigate unforeseen challenges. Moreover, Nepal’s susceptibility to tectonic activities and intense monsoon rains further exacerbate geological risks, emphasizing the importance of robust engineering practices and risk management strategies in underground infrastructure development.

Beyond geological complexities, Nepal faces significant non-geological challenges in its pursuit of underground space utilization. Limited technical expertise and specialized equipment hinder the effective execution of tunneling projects, contributing to delays, cost overruns and suboptimal outcomes. The scarcity of skilled professionals and inadequate investment in capacity-building initiatives underscore the urgency of bolstering the country’s engineering workforce and fostering knowledge transfer partnerships with international experts. Additionally, the absence of clear regulatory frameworks and guidelines for underground construction complicates project approval processes and regulatory compliance, creating uncertainty for investors and developers.

Addressing these challenges requires a holistic approach that integrates geological, technical, regulatory and institutional considerations to promote sustainable and resilient underground infrastructure development in Nepal. Strengthening technical capacity through targeted training programs and knowledge-sharing initiatives can enhance the country’s engineering capabilities and foster innovation in tunneling and excavation techniques. Furthermore, establishing clear regulatory frameworks and standards for underground space utilization can provide certainty and clarity for stakeholders while safeguarding environmental and safety concerns. Collaborative efforts between government agencies, private sector entities, academic institutions and international partners are essential for overcoming these challenges and unlocking the full potential of underground space in Nepal's infrastructure landscape.

Conclusion

In summary, Nepal is at a crucial juncture in its development trajectory, poised to leverage the untapped potential of underground space amid a myriad of challenges. Despite a historical focus on tunneling, particularly in hydropower projects, the nation faces complex geological dynamics and regulatory uncertainties that necessitate a strategic approach to subterranean development. By investing in geological surveys, adopting cutting-edge engineering practices and fostering regulatory clarity, Nepal can navigate the complexities of tunneling projects while harnessing the transformative benefits of underground infrastructure.

Moreover, by fostering collaboration, promoting public-private partnerships and prioritizing sustainability, Nepal can position itself as a leader in underground infrastructure development. From alleviating urban congestion and enhancing disaster resilience to preserving cultural heritage and mitigating environmental impact, the potential of subterranean space is vast. With concerted efforts to overcome challenges and capitalize on opportunities, Nepal can chart a path toward a more resilient, sustainable and prosperous future through the strategic utilization of underground infrastructure.