Browsing by Author "Altamira, A"

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    Calibration of structural cracking models for asphalt pavements: HDM-4 case
    (NATL INST SCIENCE COMMUNICATION, 2003) de Solminihac, H; Hidalgo, P; Salgado, M; Altamira, A
    The HDM-4 (Highway Development Management) models used for pavement management activities must be adapted to specific conditions of the country or region where they are to be used by adjusting certain calibration factors. This work presents results obtained from the calibration of structural cracking models in HDM-4 version 1.1, and comparing the results from equivalent HDM-III models. The "windows" methodology is used to reconstruct the distress performance curve of a specific road category based on the observation of conditions of diverse roads with similar characteristics (such as traffic, pavement structural capacity and climatic conditions) but different ages. Also, recommendations are made for calibrating performance models, as well as for establishing calibration factors for asphalt pavement structural cracking models more appropriate for Chilean roads. Although the results of the HDM-III and HDM-4 calibrated models have similar values, the HDM-4 version 1.1 cracking models are recommended due to their operational advantages.
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    Evaluation of a mechanism for urban road maintenance by level of service
    (THOMAS TELFORD SERVICES LTD, 2003) de Solminihac, H; Lobo, E; Jimenez, N; Altamira, A
    The agency responsible for constructing and maintaining urban roads in Chile has initiated a pilot programme under which responsibility for the maintenance and preservation of urban roads falls within the scope of the private sector, which assumes the commitment to maintain roads in an adequate condition in exchange for a pre-established payment, called urban road maintenance by level of service. The purpose of the research described in this paper was to evaluate the implementation of contracts by level of service. This evaluation was based on comparing total costs (direct and indirect) with the traditional method, considering the savings in operating costs and the impact on users as well as the benefits. Statistical information was considered relating to types of structure, types of road, travel demand, level of road distress, threshold of intervention, construction, maintenance and operating costs, and impacts. Based on the results obtained, it is concluded that it is feasible to apply urban road maintenance contracts by level of service at both a technical and an economic level, and that such contracts should be applied for specific types of road, pavement conditions and types, and contract periods.