The stabilization of slopes for infrastructure works in Colombia deserves a global view, which includes understanding the territory, regulatory compliance and comprehensive risk management.
these three approaches serve as a guide for generating projects, whose slopes are truly functional based on good engineering practices, allow the long-term operation of the associated structure and generate a positive impact on society.
Understanding the territory
Colombia, located in northwestern South America, is under the influence of three tectonic plates: South American, Nazca and Caribbean. The interaction between them has given rise to our mountain ranges, valleys, and in general, to all the geological, geomorphological and hydrogeological aspects that predominate in our country.
That is why, understanding the territory from these physical aspects must involve the following activities:
- Review of geological and hydrogeological information, as well as mass movement zoning, and seismic threat studies.
- Carrying out field tours, to identify morphodynamic processes, rock mass quality, drainage patterns and behavior of other nearby works.
- Development of geological and geotechnical exploration in accordance with local geology and established regulations.
- Understand that soil characteristics are related to the origin of their parent rock.
On the other hand, in Colombia, the rainfall pattern is very variable, which classifies the territory as humid to humid rainy. This feature of the territory is a determining factor when evaluating the stability of a slope.
In addition, Colombia is no stranger to the effects of the phenomenon of global warming or climate change, and that is why, recently, studies have been carried out on the subject. This is the case of the study, “Colombia's primary road network in the face of climate change” by the Ministry of Transportation, which seeks to quantify the level of risk of road infrastructure, considering threats such as changes in temperatures, changes in rainfall and rising sea levels until 2070. These studies have concluded that climate change will increase the risk of damage to infrastructure, so tools must be established to face these challenges based on policies and decisions of the sector.[1]
In this context, it is necessary that when designing infrastructure works related to slope stability, a global view must be included that is not limited to the verification of geometries, supports, safety factors, probability of failure (deformations and expected stresses if applicable), but that in its dimensioning, planning and construction, all the triggers of instability processes and start with the use of tools that not only look at current requests, but also the projection of extreme conditions derived from climate change.
In addition, it is necessary to include a social dimension, since the excavation and construction of slopes takes place in physical spaces where communities cohabit and link with natural resources, in the development of economic activities or to access goods and services. A tool that serves to include this dimension in the study is the one contained in documents such as “The Sustainability Policy for Transportation Infrastructure of the National Institute of Roadas-INVIAS”, which seeks to improve the level of satisfaction with the needs and demands of the socio-environmental environment in which transport infrastructure projects are developed.[2]
Regulatory compliance
In Colombia there are no explicit regulations for the design of infrastructure slopes (roads, hydroelectric projects, mining projects, etc.) Therefore, when structuring a project from design to construction, They must be established (in agreement with the project owner and/or controller) the criteria that will be used in verifying slope performance and load scenarios (drained, undrained, static and dynamic condition, influenced by rainfall and return periods associated with extreme events). In addition, factors associated with safety and probability of failure must be considered, which are acceptable for each case. The national reference standards that can be consulted for slope design are described below:
- Colombian Earthquake Resistant Standard NSR-10.
- Colombian Bridge Design Standard CCP 14.
- Terms of reference for the preparation of the EIA Environmental Impact Study for ANLA mining projects.
- Terms of reference for the preparation of the EIA Environmental Impact Study in projects for the construction and operation of ANLA hydroelectric power generation plants.
- INVIAS manual for the design, construction, operation and maintenance of road tunnels for Colombia.
- Technical Regulations for the Drinking Water and Basic Sanitation Sector — RAS.
As for international references, the reader can refer to the following list, or failing that, research other references that deal with infrastructure works similar to those being analyzed:
- Design guidelines and/or specifications from state and federal transportation agencies in the United States.
- American Railway Engineering and Maintenance of Way, Chapter 9 Seismic Design for Railway Structures.
- Bulletin 148 Selecting Seismic Parameters for Large Dams-Guidelines of the ICOLD.
Risk Management
La risk management is essential to ensure the stability of slopes in infrastructure. It is necessary to identify the natural and anthropogenic phenomena that can trigger instabilities and to define the failure mechanisms applicable to each case, with their respective probability of occurrence and level of consequences. Subsequently, construction methods, excavation sequence, stabilization, drainage, instrumentation and budget must be determined, taking into account economic viability and risk reduction.
Conclusion
An interdisciplinary vision is needed that considers the conception, construction and operation of slopes for infrastructure works, based on the interaction and coherence between geological, geotechnical, structural, hydraulic, environmental and social aspects. This comprehensive approach is essential to provide definitive solutions that guarantee the operation of the infrastructure works required by the regions and the country in their development plans.
References
- Climate Change and Risk Management — Ministry of Environment and Sustainable Development. (2022, 18 January). Ministry of Environment and Sustainable Development. https://www.minambiente.gov.co/cambio-climatico-y-gestion-del-riesgo/
- Sustainability Group. (2022). SUSTAINABILITY POLICY FOR THE TRANSPORT INFRASTRUCTURE OF THE NATIONAL ROAD INSTITUTE (INVÍAS). At the National Road Institute. https://www.invias.gov.co/index.php/normativa/politicas-y-lineamientos/9989-politica-de-sostenibilidad-para-la-infraestructura-de-transporte/file
About the author
Civil Engineer from the National University of Colombia, Medellín Headquarters, with a Master's Degree in Sciences-Geotechnics from the University of São Paulo (Brazil) and Executive MBA in Business School Educational Format (Spain). She has been working at Integral S.A. for nine years and currently, as a senior engineer, she coordinates geotechnical working groups. In his more than 10 years of experience, he participated in different engineering auditing and consulting projects for projects of different kinds (hydroelectric, road, mining projects, etc.).
