The injection of expanding polyurethane resin into the soil is a well-known technology, which every time more often is used in interventions for reinforcing shallow foundations. It is noteworthy that it is a non-destructive technology, which generated small disturbance in the structure, and that is why is very appreciate for sensitive buildings as those belonging to the country's architectural heritage.

The injection of expansive polyurethane resin into the soil is a technology that is beginning to be used for underpinning shallow foundations. It is noteworthy that this technology has been used on buildings of great historical value which are part of the country's architectural heritage. This article describes the work done on the Cardinal Diego de Espinosa Palace which consisted of injecting expanding polyurethane resin into the soil at different depths (Uretek Deep Injections) in order to mitigate the differential settlements detected in the structure. This injection technology has proven to be more effective than the more convention methods used in the past which consisted of raising the foundation by building concrete shafts, which did not manage to mitigate the causes of the pathologies observed in the palace.Key words: Underpinning, Injection, Expansive Resins, Historical buildings. ResumenLa inyección en el terreno de resina de poliuretano expansivo es una tecnología que se está comenzando a utilizar en el recalce de las cimentaciones superficiales. En este sentido, resulta más enriquecedor llamar la atención sobre aquellas actuaciones realizadas que, por ser edificaciones con un valor histórico relevante, forman parte del patrimonio arquitectónico de un país. El presente artículo describe la actuación realizada en el edificio histórico del Palacio del Cardenal Diego de Espinosa, consistente en la inyección de resina de poliuretano expansivo en el terreno a diferentes profundidades (Uretek Deep Injections), encaminada a mitigar la presencia de asientos diferenciales detectados en su estructura. Esta tecnología de inyección ha mostrado ser más efectiva que las anteriores actuaciones de recalce convencionales realizadas, recrecidos de la cimentación mediante la construcción de pozos de hormigón, en las que no se consiguieron mitigar las causas de las patologías observadas en el palacio.

The pressuremeter test in boreholes has proven itself as a useful tool in geotechnical explorations, especially comparing its results with those obtained from a mathematical model ruled by a soil representative constitutive equation. The numerical model shown in this paper is aimed to be the reference framework for the interpretation of this test. The model analyses variables such as: the type of response, the initial state, the drainage regime and the constitutive equations. It is a model of finite elements able to work with a mesh without deformation or one adapted to it.

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Model uncertainty is present in many engineering problems but particularly in those involving geotechnical behavior of pile foundation. A wide range of soil conditions together with simplified numerical models makes it a constant necessity to review the accuracy of the predictions. In this paper, the outputs of some seventy (70) pile axially-loaded tests have been reviewed with a classic numerical model to assess pile deformation. Probabilistic approach has been used to quantify uncertainties coming from soil tests, statistic uncertainty and also from the model itself. In this way, a critical review of the prediction method and a way to quantify its uncertainty is presented. The method is intended to be used in a wide range of engineering problems.

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An analysis of the geotechnical information obtained from a large number of field tests (pressuremeter) and laboratory tests (identification, state, and mechanics) on the clay deposits in the small tertiary basins associated with the Alentejo-Plasencia fault in the province of Caceres (Spain) has made it possible to classify them and predict their response to different levels of stress and strain. This geotechnical classification process must consider an appropriate model of constitution. The present article is based on the use of the Hardening Soil Model to facilitate predictions of the stress-strain behaviour of these tertiary clay deposits.

Probabilistic approaches to deal with uncertainty on soil mechanic predictions are on the rise. We developed a procedure to deal with uncertainty coming from soil conditions. It was applied to an analytical model to simulate the behavior of a soil improvement work based on rigid inclusion below a slab foundation. The model can predict the settlements of the slab. Even more, it was also able to provide a confidence level based on a probabilistic approach to the input’s variables. Outputs were compared to large-scale tests. The agreement is outstanding. We try to encourage the use of probabilistic models to solve complex geotechnical problems.