ABSTRACT
It behooves us to design the future in part, and in part it will be imposed on us. Within imposed restriction, each country should define the future that suits it best. Innovations will spring from new data, reinterpretation of data available, improved methods of analysis, improved design criteria, and new structural solutions. New data will concern earthquake origin (sources, generating mechanisms and improved catalogs), seismic wave transmission (as a result of crust exploration, knowledge of site conditions and data bases of records) and structural properties (including structural behavior, costs and consequences). We can expect more from improvements in existing methods of analysis than from the application of new branches of mathematics. Success of expert systems will hinge on the laying down of precise rules. Efficient use of new computer capabilities will require development of appropriate languages. The most significant advances can be expected to come from the conception of new structural solutions. There will doubtless be control systems, new structural configurations, new uses of existing materials and new materials. The main benefits will come not so much from improved building codes but from improved means for having the codes complied with. We should speak of futures rather than of future. Cultural and economic differences among countries will diversify the future. So will local differences in the nature of ground motions; and our uncertainties prevent our pinpointing the future even at the local level. Correlation between long economic cycles and major technological thrusts suggests that the next important wave of improvements in our field will begin early next century (AU)
Subject(s)
Earthquakes , EngineeringABSTRACT
We first compute the human-capital value that society should invest to reduce, by a given small amount, the seismic risk to human life. The result amounts to taking the social value of a human life equal to the expected present value of the person's contribution to the gross domestic product during the rest of her life, and is generally somewhat smaller under a constant than under a Dirac-delta hazard function. Next we deal with the value of a person's life to herself. We use the person's utility curve per unit time as a function of time, assume that she will repay a just loan whenever it is most convenient to her and we introduce a kind of Pareto optimality. Results can be roughly approximated through a time independent utility curve. This value always exceeds the net human-capital result ("net" in the sense of discounting the minimum expenditure needed for survival) and under reasonable assumptions exceeds twice this much. Because repayment rates are mostly externally imposed, the value to society (without recognizing psychological and economic impacts) is smaller than that to the person herself but still exceeds the lower limits quoted. The value depends, though not significantly, on the shape of the hazard function. Nonuniformity of wealth among the population causes a small increase in the social value of anonymous life. Ethical considerations lead to age-specific values intermediate between those computed and the value of an anonymous life. We also pay fleeting attention to physical and psychological harm to people. Finally we argue that the government should only partially recognize differences in psychological impact as a function of the cause of death or injury (AU)
Subject(s)
Earthquakes , Engineering , Socioeconomic FactorsABSTRACT
Se exponen los trabajos resultantes de la mesa redonda Macrosismos y sus efectos sociales, políticos y económicos realizada en el año de 1989
Subject(s)
Earthquakes , Socioeconomic Factors , Mexico , Risk Assessment , Post Disaster Reconstruction , Behavior , Mass MediaABSTRACT
Expone casos de lugares que históricamente han padecido de movimientos sísmicos fuertes y los efectos que estos producen en la población
Subject(s)
Humans , Earthquakes , Risk Assessment , MexicoABSTRACT
Future ground motions at a soft site of the Valley of Mexico are estimated for a postulated M 8.2 earthquake with epicentral distance of 280 km. Three techniques are used: a) semiempirical estimation of fourier acceleration spectra at a hard -reference- site plus empirical determination of site effects through empirical transfer functions; b) semiempirical computation of Fourier spectra at the reference site with theoretical calculation of site response using 1D horizontal S-wave propagation corrected to account for surfacewaves; c) use of an M 6.9 recording as the Green's function of the postulated event (AU)
