No abstract

SummaryThe growing phenomenon of urbanization in developing countries has led to a large number of settlements characterized by a deficient habitat (slums), lacking security of tenure and an adequate provision of urban services that affect the quality of the lives of its citizens. Over time, these settlements are improving their standards of quality in the provision of public services and their security of tenure. The interrelationship between security of tenure, improved urban services and housing improvement provides the key to evaluating the actions that improve the quality of life of its inhabitants. The proposed approach involves the establishment of a methodology for reading the evolution of the forms of urban growth in terms of incremental levels of security of tenure (P), urban services (U), and building (E). In order to develop the analysis, an urban periphery index has been developed, based on the forms of evolutionary growth, improved services and security tenure, as well as on accessibility (distance to the centre and slope). The analysis of the correlation between the urban periphery index and the spatial distribution of social strata and land values, in the evolution of the urbanization of the city of Cucuta (Colombia), highlights the relevance of the elements of the urban periphery index as key factors to improve the quality of life..

En esta investigación se explora el estado del arte respecto a los análisis de accesibilidad territorial y el uso de los mismos como instrumentos de planificación a nivel mundial. Se muestra claramente la metodología general de aplicación y la amplia gama de posibilidades existentes como un potente instrumento de planificación territorial a nivel urbano y regional. A lo largo del artículo se abordan ejemplos que muestran cómo la aplicación de esta metodología puede potenciar la toma de decisiones respecto a un proyecto de intervención futura, o reflejar necesidades en los cambios operativos de un servicio de transporte. Este instrumento de planificación se soporta en el procesamiento y análisis geoestadístico de una gran cantidad de datos, en su gran mayoría datos de posicionamiento satelital, características operativas, topológicas y geográficas de las redes que se va a estudiar. Para ambos niveles de planificación territorial se obtienen resultados gráficos valiosos que permiten identificar el impacto de las intervenciones o de los cambios operativos sobre el territorio. Este artículo muestra las bondades de la metodología como instrumento de planificación y concluye sobre la aplicación de la misma.

In South America, especially in the Andean region, many communities are isolated and their development is limited due to the difficulties in communicating with urban areas, because the lack of adequate road infrastructure. Most of this problem is due to economic issues and lack of attention from governments. Moreover, the Guaduaangustifolia Kunth (Guadua-a.) is a bamboo that grows in most of the Americas. This material has a resistance – weight ratio similar to structural steel also presenting additional benefits such as soil stabilization, flow regulation, and a high CO2 fixation rate to the ground. In addition the Guadua-a. growth cycle spans from 3 to 5 years. All of these makes the Guadua-a. in highly renewable material. This paper presents an alternative for the construction of Guadua-a. structural modules for pedestrian bridges, as a solution to the lack of infrastructure in village roads and even in suburban areas. In the proposed model, the bridge would be built by the community in a short time, taking advantage of existing Guadua-a. in the area, and establishing an industrialized cultivation of it, to enable them to have enough material for maintenance and replacement of sections as necessary. A numerical structural analysis was performed to determine the maximum possible span under load specifications from Colombian bridge building code. The results shows that a bridge up to 21m of span can be constructed using the module. The span can be increased drastically when the module is combined with wire-cable or an arc shaped configuration, however, the module was assessed to be used in straight truss bridges because this setting carries the largest loads on the elements. Real scale load tests were conducted on a full scale physical model of the module, the structural elements and the connection between the modules.