Estimation of parameters in geotechnical backanalysis. II- Application to a tunnel excavation problem

A general statistical framework to perform backanalysis in geotechnical problems from field instrumentation has been presented in a companion paper. Here, an application to a real case involving the excavation of a tunnel in stiff overconsolidated clay is described. Both, extensometer and inclinometer measurements are used as input data and elastic moduli of the ground and the value of the K0 coefficient are estimated. The finite element method is used as the computational procedure to solve the direct problem, and has been coupled to the identification algorithm as described in the companion paper. In addition, a discussion on the reliability of the parameters identified is presented

Ecerint incindi et extrahy lapides de lapidicina monasterii. Troubles and Conflicts around Quarries in Hispanic Middle Ages

El estudio de las canteras durante la Edad Media en la Península Ibérica constituye una herramienta fundamental para comprender el fenómeno constructivo que se desarrolla en todo el Occidente Medieval. Los testimonios localizados en la documentación no son muy numerosos y los que se vinculan con conflictos se constituyen como raras excepciones. Sin embargo, estos registros son sumamente ilustrativos del rol de estas propiedades, también sus materiales, y asimismo permiten engrosar el conocimiento existente sobre las dinámicas del poder en cuanto que en los litigios están representados los principales actores de la época. El concejo y los monasterios en la mayoría de las ocasiones. Los casos analizados corresponden desde finales del siglo xii hasta el primer cuarto del xiv y se identifican en los territorios de Castilla y de Aragón.The major attention given to the political, social and religious processes developed in the Visigothic period has meant that very often historians have left aside other types of topics which, like those of an economic nature, offer equally rich information for understanding the social history of Visigothic society. The dynamics of hunting are one of those issues that suffer from a lack of consideration by historiography. The aim of this study is, apart from filling the historiographical gap on this issue, to understand the social and economic impact of hunting in Visigoth society and its insertion in the general trends of the post-imperial West. To this end, and in order to offer the most comprehensive vision possible, we will distinguish in our analysis the aristocratic uses from those more commonly developed by the peasantry

Estimation of parameters in geotechnical backanalysis. I- Maximum likehood approach

The estimation of soil and rock parameters based on field instrumentation data is a common procedure in geomechanics. The use of system identification and optimization techniques allows the performance of this type of analyses in a more rational and objective manner. In this paper a probabilistic formulation for the backanalysis problem is presented. The procedure described involves the evaluation of the measurement covariance matrices, which are derived for some geotechnical instruments used in field instrumentation. The algorithm used to solve the mathematical problem of optimization is also presented, as well as its coupling to a finite element code. The algorithm requires the computation of the sensitivity matrix, which can be evaluated “exactly” in terms of the finite element method. Finally, a synthetic example, based on the excavation of a tunnel, is presented in which the elastic modulus E and the K0 parameter of the material are identified from measured displacements. The effect of the number of measurements and their error structure is also discussed

Parameter and variance estimation in geotechnical backanalysis using prior information

A probabilistic framework to perform inverse analysis of geotechnical problems is presented. The formulation allows the incorporation of existing prior information on the parameters in a consistent way. The method is based on the maximum likelihood approach that allows a straightforward introduction of the error structure of field measurements and prior information. The difficulty of ascribing definite values to the uncertainties associated with the various types of observations is overcome by including the corresponding variances in the set of parameters to be identified. The inverse analysis results in a minimization problem that is solved by coupling the optimization technique to the finite element method. Two examples are presented to illustrate the performance of the method. The first one corresponds to a synthetic case simulating the excavation of a tunnel. Young's modulus, K0 value and measurements variances are identified. The second case concerns the excavation of a large underground cavern in which again Young's modulus and K0 are identified. It is shown that introduction of prior information permits the estimation of parameters more consistent with all available informations that include not only monitored displacements but also results from in situ tests carried out during the site investigation stage

Cibertexto como ideología y viceversa. Crítica ideológica de los videojuegos de Paradox desde un modelo cibertextual

La crítica ideológica es la herramienta básica para el análisis de la realidad social y la crítica del capitalismo desde el marxismo. The ideological critique is the basic tool for the analysis of social reality and the marxist critique of capitalism. A crítica ideológica é a ferramenta básica para a análise da realidade social e a crítica do capitalismo do marxismo.&nbsp

Los que vivimos. Reapropación crítica del pensamiento reaccionario de Ayn Rand

This work aims to investigate the relationship between reactionary literature, the committed literature with conservatives or political right positions, with the ideology and policies of the right about commodification of space and time from Ayn Rand's first novel, We the living. To do this, we start from the idea of critique as a mediator, as a discipline that puts the work in communication with its time and with the present and allows us to do politics with something that in principle can move away from the ideals of the reader. After this, a critical analysis of the novel and its themes is carried out to finally observe the figures it proposes from a different perspective than the author's intention.  El presente trabajo pretende indagar en la relación entre la literatura reaccionaria, la literatura comprometida con posturas conservadoras o de derechas, con la ideología y las políticas de la derecha acerca de la mercantilización del espacio y el tiempo a partir de la primera novela de Ayn Rand, Los que vivimos. Para ello se parte de la idea de crítica como mediadora, como disciplina que pone en comunicación la obra con su tiempo y con el presente y nos permite hacer política con algo que en principio se puede alejar de los ideales del público lector. Tras esto se realiza un análisis crítico de la novela y sus temas para, por último, observar las figuras que propone desde una perspectiva diferente a la intención de la autora. &nbsp

The visible thing and the invisible thing in the romanesque: sources and study of symbols of the profane sculpture

Profane is defined as "that which is not holy nor has holy usefulness", however in themedieval culture will be excessively complex to separate the profane and religious world, as well asthe specific knowledgeof thedemystifiedpicture role in a strictly ecclesiastic context.Due to these questions, it is generated the necessity of raising a specific study about the profane in the Romanesque sculpture in Salamanca which leads to provide some answers from new methodological approaches.The number of investigational studies performedup tonowabout this issue isnot sohighandthe scarce documental fonts, lost of visual memories, along with the changes made in the temples, limit evenmore the task to be done.Lo profano se define como "aquello que no es sagrado ni sirve a usos sagrados", sin embargo,enlaculturamedieval resultará excesivamente complejo independizar mundo profanoy religioso, así como el conocimiento específico de la función que desempeñan las imágenes desacralizadas, dentro de contextos estrictamente eclesiásticos. En el marco de estas interrogantes, se genera la necesidad de abordar un estudio específico sobre lo profano en la escultura románica en Salamanca, que nos permita ofrecer algunas respuestas desde nuevos enfoquesmetodológicos. Las investigaciones efectuadas sobreestamaterianosonmuynumerosas y las escasas fuentesdocumentales,y lapérdidade lamemoriavisual, junto a las transformaciones que han sufrido los templos, limitan aún más la labor a desempeñar

Backanalysis of preloading

The paper presents the application of a backanalysis methodology to the inverse analysis of preloading soft clays. The methodology is based on an appropriate selection of the objective function and it uses a novel adaptive genetic algorithm approach to solve the resulting optimization problem. The methodology is applied first to a synthetic example followed by an application to an intensely instrumented preload test. The selected observations are the evolution along time of displacements and pore water pressures. The key parameters to be identified are those with major influence on the results: compressibility and permeability of the soil. It is shown that the confidence in parameter estimation varies significantly depending on the time at which the observations are considered and the type of them (displacements vs. pore water pressure). The possibility of extrapolating early results to later stages of the preloading is also explored. The usefulness of the method in engineering problems is demonstrated by the application to a preloading performed to improve the soft ground of the Water Treatment Plant located in the Llobregat delta near Barcelona.Postprint (published version