Hydraulic Evaluation of the Design and Operation of Ancient Rome's Anio Novus Aqueduct

This paper evaluates conveyance and flow characteristics for the Anio Novus, the aqueduct bringing water from the greatest distance to ancient Rome. Travertine accumulations, deposited from water on floor and walls, were used to reconstruct the flow rate and associated spatial and temporal variations. Hydraulic quantities (e.g., flow depth and velocity) markedly varied over the course of the aqueduct, implying that constraints such as topography and construction techniques were combined with hydraulic considerations to determine the aqueduct layout. Design practices differed along the aqueduct and channel size design was not based exclusively on anticipated carrying capacity, tending towards larger‐than‐necessary design based on experience.     

From private initiative to public intervention in Spanish water management: the case of the Muga and Fluvià rivers (1850–1930)

During the second half of the nineteenth century and the first third of the twentieth century, Spain, along with some other European countries, underwent a process of transition regarding water resources management. One of the most obvious transformations that occurred during this period was the increasing lead taken by the government in the building of large hydraulic structures and the subsequent decrease in the influence of private initiative in this matter. The government's aim was to exploit the water resources provided by the rivers to their full, and in particular to use the water that was destined for irrigation to maximum effect. The repeated failure of projects promoted by private companies led the government, not without problems, to enact regulations and create hydraulic plans to be put into motion by the public sector. This change in focus is the key to understanding the frenetic pace of hydraulic infrastructure construction that occurred later and which made Spain one of the world's leading nations in terms of indicators such as the number of large reservoirs in use. This article focuses on the transition from private initiative to public intervention and evaluates the main stages of this process in Spain. The cases of the basins of the Muga and Fluvià rivers, located in the extreme north-east of the Iberian Peninsula in Catalonia, are described in light of this process. This research attempts to verify that despite their modest size and their distance from the main decision-making centres, these two cases reflected the situation at the national level. This was just one of the many local effects of the transition process of water resources management in Spain, even though the results of this transformation would be neither immediate nor effective in the short term.     

King Bhumibol: The Symbolic “Father of Water Resources Management” and Hydraulic Development Discourse in Thailand

The present Thai monarch’s reputation in matters hydrological is an integral element of the mythology and symbolism that have characterised his reign. Royalists have carefully constructed the king as a semi-deified “Father of Thai Water Management”, “Royal Rainmaker”, wise inventor of hydraulic technology and planner of “royal initiatives” over a period of six decades. Yet, despite the links that are often drawn between water resources control, spiritual cosmology and political governance surrounding pre-modern Southeast Asian rulers, there has been surprisingly little critical scholarship undertaken on this contemporary aspect of kingship and state-making in Thailand. This paper examines the evolving discourse surrounding the monarchy and hydraulic development as a response to a perceived neglect regarding the central role of water in cementing the king’s power and legitimacy. It argues that King Bhumibol’s apparent hegemony in the national water resources governance paradigm has been an essential element underpinning the longevity and authority of his reign, partly facilitated through the workings of a network of allied strategic interests. Drawing from a range of sources, this paper makes a cautious start in addressing the subject and attempts to open up a space for further critical reflection and discussion regarding the significance of water resources control to Thailand’s royal statecraft.     

Investigation of coupled hydraulic–geomechanical processes at the KTB site: pressure‐dependent characteristics of a long‐term pump test and elastic interpretation using a geomechanical facies model

The German Continental Deep Drilling Program comprising a pilot borehole down to 4000 m and a main borehole down to 9101 m in southeast Germany (KTB) is continuing to provide a unique opportunity for the identification of important factors and processes in deep‐seated fluid and energy transfer. In situ stress conditions significantly impact flow, transport and exchange characteristics of fracture networks that dominate the permeability of crystalline reservoir rocks. In this paper, several scales of information are combined to present a fully three‐dimensional hydraulic finite element model of the principal KTB fault zones, and linked to a geomechanical model describing the alteration of the hydraulic parameters with stress changes caused by fluid extraction. The concept of geomechanical facies is introduced to define and characterize architectural elements in the subsurface system. Evaluation of a long‐term pump test in the KTB pilot hole, June 2002–July 2003, coupled with a geomechanical model gives an insight into some of the elastic and nonelastic processes controlling hydraulic transport in the basement rocks. Trends in the decline of the permeability and the degree of storage in the system could only partially be explained by elastic processes, clearly indicating the importance of nonelastic processes. A number of inelastic processes are suggested as areas for further research.     

Finite element modeling of slug tests in an aquifer with stratigraphical and structural heterogeneities

Slug interference tests using an array of multilevel active and monitoring wells permit enhanced aquifer characterization. Analyses of these field test data rely on numerical inverse models. In order to provide synthetic data sets and to have a better understanding of the flow mechanisms, we used a three-dimensional finite element analysis (FEHM) to explore the effects of idealized, stratigraphical (strata) and structural (faults) heterogeneities with low permeability values on the transient head field that is associated with slug tests in an aquifer. Firstly, we tested our model on homogeneous aquifers and the effectiveness of our modeling strategies have been validated via the excellent agreement of our modeling results with those of the semi-analytical model of Liu & Butler (1995) . In our heterogeneity investigations, we embedded vertical and horizontal zones of lower permeability into a homogenous, isotropic, and confined aquifer to represent low-permeability faults and strata respectively. A slugged interval is located at the center of the aquifer. Effects of strata thickness and permeability contrast as well as other effects associated with the offset of low-permeability strata were explored. In particular, modeling results are represented by contour maps of peak travel time and maximum head perturbation of generated hydraulic pulses. Furthermore, various phenomena, such as real-time matrix diffusion, intermittent matrix–fracture interactions, and faster pulse arrival through a longer flow trajectory, are concretely presented in the snapshots of head perturbations in the aquifer. Our finite element modeling provides useful information for understanding the behaviors of diffusive pressure propagation in an aquifer with stratigraphical and/or structural heterogeneities, and for designing hydraulic tomography to enhance aquifer characterization.     

Characterization of Hydraulic Lime Mortar Containing Opuntia ficus-indica as a Bio-Admixture for Restoration Applications

Many successful and long lasting structures that contain lime mortars are hydraulic in nature. Organic admixtures are added to lime mortar mix to modify their fresh and hardened state properties. The present work proposes plant extract as bio-admixture for repair mortar towards the protection of heritage structures. The effect of cactus extract on the properties of hydraulic lime mortar is studied. Mortar´s composition is selected with respect to the composition of historic mortars and modern restoration practice. Cactus extract was added to the lime sand mixture with varying concentrations (25%, 50%, 75%, and 100%) and with different fermentation periods of 0, 1, and 2 days The consistency and workability of modified mortar, mechanical behavior, water absorption, porosity, and water/salt absorption through capillary rise, salt crystallization have been studied. Micro structural properties of the resulting mortar have been evaluated by XRD and FT-IR to identify their mineralogical composition and morphology by SEM-EDX. It is observed that addition of 75% cactus extract with 1-day fermentation produces maximum positive effect on the strength and durability properties of lime mortar. It improves the mechanical characteristics, limits water and salt absorption by capillarity into mortar and also show resistance to salt crystallization cycles.     

Historical Mortars from the Fortified Upper Town of Eivissa (Balearic Islands,Spain)

Samples of mortars and stone of Portal de ses Taules from the Renaissance city walls of Eivissa (16th century) were characterized using thermal analysis— thermogravimetry and derivative thermogravimetry (DTG)—x-ray diffractometry, and scanning electron microscopy. The granulometric fraction of particle size <63 μm was selected as representative of the binder, while the fraction 0.5–1 mm was taken as representative of the aggregate in order to characterize mortar samples. The results show that local materials were used. Lime was the main component of most of the samples tested. Thermal analysis revealed the hydraulic nature of the lime mortars. High amounts of sodium chloride were found in the samples analysed.     

Structural Assessment of Ancient Masonries before and during a Rehabilitation Process

ABSTRACT

The rehabilitation of old buildings requires detailed knowledge of the mechanical characteristics and stress state of the structural elements, which play an important role in the intervention process. In this sense, non-slightly destructive tests can estimate structural characteristics with good precision at relatively low costs. Consequently, this article presents a device, based on the flat jack technique, applied to continuous stress monitoring over time. It also focuses on the onsite determination of service stresses and its continuous monitoring in several masonry buttresses of a historic building, as well as the assessment of the structural safety before, during, and after an intervention process. A brief analysis of the research is performed, and the motivation and the methodology adopted are described. Finally, the evolution of the measurements recorded and the analysis of the results achieved are detailed. The study enabled recommendations to be made to the intervening agents that guarantee structural safety.