La variable tiempo en el cálculo de acciones para estructuras de edificación

El presente estudio profundiza en los valores las acciones que actúan sobre una estructura conforme a la vida útil para la que se proyecta inicialmente especialmente cuando su vida útil es menor del valos estándar. Esto sucede frecuentemente, en el campo de la rehabilitación

The time variable in the calculation of building structures. How to extend the working life until the 100 years?

The idea that a building and consequently its structure is for a lifetime has stopped being a reference. CTE establishes that the life utility of a normal construction structure should be of 50years. If the time variable is introduced in the calculation of actions on structures, seems evident thatdifferent values can be used for a standard building, for a provisional structure with ≤ 10 years of life utility or for a monumental building with a life utility of 100 years. The present presentation follows at all moment, the directives and formulations given in the different structural Eurocodes, till the moment not included in the CTE. Finally the values of the actions that must be used to extend the life utility of a building until. 100 years will be deduced, also it suitability and e conomic feasibility will be discuss

Comparison of the O3 chemistry in the Po Valley with that in the Benelux region as simulated with MECO(n)

This study investigates the contributions of anthropogenic non-traffic (i.e. households, industry, etc.) and land transport emis- sions to the ozone budget in Europe and Southeast Asia. For this we performed two simulations with the global/regional che- mistry-climate model MECO(n) including a source apportionment method for ozone to investigate regional differences bet- ween the chemical regimes, especially of the ozone formation potential. Our findings show that contributions from global anthropogenic non-traffic emissions to ground-level ozone are larger in Southeast Asia than in Europe. The contrary applies for the global land transport emissions, which are more important in Europe compared to Southeast Asia

ICON in Climate Limited-area Mode (ICON release version 2.6.1): a new regional climate model

For the first time, the Limited-Area Mode of the new ICON (Icosahedral Nonhydrostatic) weather and climate model has been used for a continuous long-term regional climate simulation over Europe. Built upon the Limited-Area Mode of ICON (ICON-LAM), ICON-CLM (ICON in Climate Limited-area Mode, hereafter ICON-CLM, available in ICON release version 2.6.1) is an adaptation for climate applications. A first version of ICON-CLM is now available and has already been integrated into a starter package (ICON-CLM_SP_betal). The starter package provides users with a technical infrastructure that facilitates long-term simulations as well as model evaluation and test routines. ICON-CLM and ICON-CLM_SP were successfully installed and tested on two different computing systems. Tests with different domain decompositions showed bit-identical results, and no systematic outstanding differences were found in the results with different model time steps. ICON-CLM was also able to reproduce the large-scale atmospheric information from the global driving model. Comparison was done between ICON-CLM and the COnsortium for Small-scale MOdeling (COSMO)-CLM (the recommended model configuration by the CLM-Community) performance. For that, an evaluation run of ICON-CLM with ERA-Interim boundary conditions was carried out with the setup similar to the COSMO-CLM recommended optimal setup. ICON-CLM results showed biases in the same range as those of COSMO-CLM for all evaluated surface variables. While this COSMO-CLM simulation was carried out with the latest model version which has been developed and was carefully tuned for climate simulations on the European domain, ICON-CLM was not tuned yet. Nevertheless, ICON-CLM showed a better performance for air temperature and its daily extremes, and slightly better performance for total cloud cover. For precipitation and mean sea level pressure, COSMO-CLM was closer to observations than ICON-CLM. However, as ICON-CLM is still in the early stage of development, there is still much room for improvement

Comparison of the O3 chemistry in the Po Valley with that in the Benelux region as simulated with MECO(n)

Non-traffic (i.e. households, industry, etc.) emissions and land transport emissions are important anthropogenic precursors of tropospheric O3 and affect the air quality and contribute to global climate change. In order to improve air quality and mitigate climate change, robust knowledge of the amount of O3 formed by different emission sources is required. This study investigates the contributions of the different emission sectors to the ground-level ozone budget in Europe and Southeast Asia. For the present study we applied the MECO(n) model system, which couples the global chemistry-climate model EMAC on-line with the regional chemistry-climate model COSMO-CLM/MESSy. We used MECO(n) with a source apportionment method for ozone to investigate regional differences of the contributions from different emissions to ground-level ozone. Our findings show that contributions from anthropogenic non-traffic emissions to ground-level ozone are larger in Southeast Asia than in Europe. The contrary applies for the land transport emissions, which are more important in Europe compared to Southeast Asia

COVID-19 induced lower-tropospheric ozone changes

The recent COVID-19 pandemic with its countermeasures, e.g., lock-downs, resulted in decreases in emissions of various trace gases. Here we investigate the changes of ozone over Europe associated with these emission reductions using a coupled global/regional chemistry climate model. We conducted and analysed a business as usual (BAU) and a sensitivity (COVID19) simulation. A source apportionment (tagging) technique allows us to make a sector-wise attribution of these changes, e.g. to natural and anthropogenic sectors such as land transport. Our simulation results show a decrease of ozone of 8% over Europe in May 2020 due to the emission reductions. The simulated reductions are in line with observed changes in ground level ozone. The source apportionment results show that this decrease is mainly due to the decreased ozone precursors from anthropogenic origin. Further, our results show that the ozone reduction is much smaller than the reduction of the total NOx emissions (around 20 %), mainly caused by an increased ozone production efficiency. This means that more ozone is produced for each emitted NOx molecule. Hence, more ozone is formed from natural emissions and the ozone productivities of the remaining anthropogenic emissions increase. Our results show that politically induced emissions reductions cannot simply be transferred to ozone reductions, which needs to be considered when designing mitigation strategies