This study evaluates the relationship of the Civilian Conservation Corps' stonework in Indiana's state parks and the National Park Service's design guidelines for stone landscape features. The design guidelines were instrumental in establishing an overall design approach for many of the stone structures evaluated in this study. A general history of the Civilian Conservation Corp program provides the context for the program as well as the relationship to stonework in Indiana's state parks. Through a sampling of stone landscape features in six Indiana state parks it can be concluded that the Civilian Conservation Corps were impacted by the National Park Service's design guidelines. At the same time the Civilian Conservation Corps deviated from the guidelines and improvised with their own variation. / Department of Architecture

Un mur de soutènement en pierre sèche (MSPS) est un ouvrage vernaculaire construit par empilement de blocs rocheux sans liant. Ce type de mur a fortement sculpté les campagnes françaises mais a aussi été utilisé par le passé dans des ouvrages de soutènement que ce soit routier ou ferroviaire. Pourtant, l’utilisation de cette technologie a disparu au cours du 20e siècle au profit de solutions industrialisées comme le béton armé. Face à ce patrimoine vieillissant, il est très difficile de proposer des protocoles de réparation alors que la réglementation associée à ces ouvrages est inexistante. Pour les mêmes raisons, alors que cette technologie répond parfaitement aux questions soulevées par le développement durable, elle est rarement envisagée ou retenue par les prescripteurs. La rupture des MSPSs neufs peut apparaître à cause de : (1) une poussée excessive du remblai soutenu par le mur, (2) un effort concentré excessif présent sur la surface du remblai et proche de la tête du mur. Ces deux causes induisent deux types de rupture très différents, respectivement : (1) rupture en déformation plane, (2) rupture par apparition d’un ventre. Trois expériences récentes à l’échelle 1 des MSPSs chargés par : (1) une poussée hydrostatique, (2) un remblai, (3) un remblai avec une force concentrée sur la surface de ce dernier, ont permis d’identifier certains phénomènes mis en jeu dans ces ruptures. Ce travail de thèse contribuera alors au développement de nouveaux outils scientifiques mais aussi à valider des outils existants pour dimensionner les MSPSs. Les expériences réalisées à l’échelle 1 serviront alors de cadre à ce travail pour valider les outils développés. Nous avons choisi d’utiliser une approche aux éléments discrets (MED) où chaque bloc de pierre du mur est modélisé individuellement, respectant ainsi la nature-Même de l’ouvrage réel. Dans un premier temps, une rupture de type déformation plane est modélisée par une approche discrète pure et une approche discrète-Continue. Les atouts et inconvénients de chacune des méthodes sont mis en avant. Une validation quantitative des modèles numériques est faite en comparant la hauteur critique de chargement avec les expériences à l’échelle 1. Ensuite, on étudie la sensibilité de plusieurs paramètres géométriques et mécaniques sur la hauteur critique de chargement, tout comme l’influence de la cohésion du remblai. Enfin, une première modélisation 3D de type qualitative sur la rupture des MSPS par un chargement concentré en surface du remblai est présentée. Les problèmes de modélisation sont soulevés et l’influence de la forme des blocs dans le processus de rupture est étudiée. / A dry-Stone retaining wall (DSRW) is a vernacular structure constructed by stacking the stone blocks without using any binder. In the past, this wall has been extensively used, shaping the French countryside area, built either for road or railroad retaining wall. However, the use of this technology has disappeared during 20th century, due to the emergence of more industrialized materials such as reinforced concrete. Confronted by these ageing heritage structures, it is very difficult to propose a proper reparation procedure since the building codes associated with this structure are nonexistent. For the same reason, though this technology perfectly answers the questions raised by the concept of sustainable development, in practice this structure is rarely considered or used by the engineering advisors. The failure of the newly built DSRWs can be attributed to the following reasons: (1) an excessive pressure of backfill retained by the wall, (2) a presence of an excessive concentrated load on the backfill surface, close to the top part of the wall. These two types of loading lead to two very different types of failure, respectively: (1) plane strain failure, (2) bulging failure. Three recent experimental campaigns of DSRWs loaded with: (1) hydrostatic pressure, (2) backfill, (3) backfill with a concentrated on its surface, provided a better understanding of phenomena involved in these failures. The work presented in this PhD thesis contributes to the development of new scientific tools capable to help design the DSRWs, as well as validating existing tools. The recent full-Scale experimental campaign will serve as a basis to the validation of the developed numerical tools. We have chosen to use a discrete element method (DEM) where each stone block of the wall is modeled individually, complying with the nature of real DSRW. In the first place, the plane strain failure is modeled by a purely discrete approach and a discrete-Continuum approach. The advantage and inconvenient of each method will be presented in advance. A quantitative validation of numerical models is provided by comparing the critical height of loading with results derived from the full-Scale experimental campaign. Thereafter, a 3D qualitative model of DSRWs loaded with a concentrated load on the backfill surface is presented. The modeling problem is noted and the influence of the block form in regards of the related failure mechanism is studied.

<p>Following paper deals with the questions about prehistorian and medieval settlements in the Mälar Valley and their relations to the historically known hamlets or single farmsteads from the 17^th- and 18^th-century cadastral maps. Models over settlement development through the period A.D 200 to 1700 done by geographers Ulf Sporrong and Dan Carlsson are tested and compared to the knowledge won by recent archaeological excavations. Is there a connection between the older settlements linked together by dry-stone walls and the late Iron Age settlements? Does the picture differ from the one presented for the Gotland region? How well are the general theories about different settlement development depending on basic natural conditions as for the potentials for cultivation and topography, corresponding to the physical remains?  Are there other factors involved when the settlement structure takes its form?</p><p>The methods that are used here constitutes mainly of a comparison between different locations in the Mälar Valley that has got a well known prehistory thanks to extensive archaeological excavations. Cadastral maps, soilmaps, topography maps and maps over ancient monuments are intertwined to the same map and analyzed through works in Geographical information systems.</p><p>The results of this study reveal an interesting suspicion in the continuity-question through the Iron Age. Certain settlements seem to be more stable than what was earlier assumed in the general models. This occurrence of continuous use of sites must also be seen in a spatial context and not only a pattern formed by randomly chosen locations. The research has shown that it may be connected to the local political power in the Iron Age community. Related to this are also the different settlement forms where more than one unit occurs on a site. Concerning the different natural landscapes both disparities and similarities are found when it comes to the development that precedes the given situation on the cadastral maps. The conclusion is that the recent archaeological excavations definitely have shown us a more complex situation than what was once outlined in the early years of landscape archaeology.</p>

Following paper deals with the questions about prehistorian and medieval settlements in the Mälar Valley and their relations to the historically known hamlets or single farmsteads from the 17th- and 18th-century cadastral maps. Models over settlement development through the period A.D 200 to 1700 done by geographers Ulf Sporrong and Dan Carlsson are tested and compared to the knowledge won by recent archaeological excavations. Is there a connection between the older settlements linked together by dry-stone walls and the late Iron Age settlements? Does the picture differ from the one presented for the Gotland region? How well are the general theories about different settlement development depending on basic natural conditions as for the potentials for cultivation and topography, corresponding to the physical remains?  Are there other factors involved when the settlement structure takes its form? The methods that are used here constitutes mainly of a comparison between different locations in the Mälar Valley that has got a well known prehistory thanks to extensive archaeological excavations. Cadastral maps, soilmaps, topography maps and maps over ancient monuments are intertwined to the same map and analyzed through works in Geographical information systems. The results of this study reveal an interesting suspicion in the continuity-question through the Iron Age. Certain settlements seem to be more stable than what was earlier assumed in the general models. This occurrence of continuous use of sites must also be seen in a spatial context and not only a pattern formed by randomly chosen locations. The research has shown that it may be connected to the local political power in the Iron Age community. Related to this are also the different settlement forms where more than one unit occurs on a site. Concerning the different natural landscapes both disparities and similarities are found when it comes to the development that precedes the given situation on the cadastral maps. The conclusion is that the recent archaeological excavations definitely have shown us a more complex situation than what was once outlined in the early years of landscape archaeology.