Breakwater Engineering

Abstract

Breakwaters have been built for thousands of years to protect harbours and coasts against the waves. Because of their very nature, breakwaters are exposed to strong wave attack. During recent years a number of newly constructed breakwaters have been severely damaged: Sines in Portugal in the winters of 1978 and 1979; Arzew-el-Djedid in Algeria in 1980; Tripoli, Libya, in beginning of 1981; Gioja Tauro in Italy in 1980; San Ciprian, Spain, during the winter of 1980. These recent examples of breakwater failure are not unique: there have frequently been reports of storm damage. One can even say that a rubble-mound breakwater is designed to absorb a certain amount of damage during its lifetime. What now alarmed the world of designers and builders of such structures, however, was the unprecedented increase in the number of failures, the fact that the breakwaters were either under construction or had been just completed and also the extent of damage in each of the above cases, the total damage being estimated as a thousand million US dollars.

So far, no overall picture has been presented. All failures were individually investigated. The investigation reports left few issues unexamined, but remain confidential themselves. The Delft Hydraulics Laboratory participated in some of the damage investigations and was entrusted with the hydraulic investigations for the rehabilitation of all five breakwaters. A unique chance, therefore, existed for the development of an overall picture. Without affecting the confidentiality of the individual cases, the most important deficiencies in the design of rubble-mound breakwaters are treated in this paper. A plan is made for a design approach in which hydraulic, structural and geotechnical aspects are integrated. The state of the art of each of these different aspects is presented globally, emphasizing the interactions between them and the consequences of an integral approach for the design methods.     

Relational complexity and the imaginative power of strategic spatial planning1

This paper explores the imaginations of place and spatial organization and of governance mobilized in recent experiences of strategic spatial planning for urban regions in Europe. Drawing on examples of such experiences, it examines how far these imaginations reflect a relational understanding of spatial dynamics and of governance processes. Spatial imaginations are assessed in terms of the nature of the spatial consciousness expressed in a strategy, the way the multiple scales of the social relations of a place are conceived, and the extent to which relational complexity is understood and reflected in a strategy. Governance imaginations are assessed in terms of how the relation between government and society is imagined, how the tensions between functional/sectoral and territorial principles of policy organization are addressed, and what assumptions are made about the nature and trajectory of transformative processes in governance dynamics. The paper concludes that signs of a recognition of the “relational complexity” of urban and regional dynamics and of territorially-focused governance processes can be found in these experiences, but a relational understanding is weakly-developed and often displaced by more traditional ways of seeing place/space and governance process. The paper concludes with some comments on the challenge of developing a stronger understanding of “relational complexity” within strategic spatial planning endeavours.     

Temper mixture models and assessing ceramic complexity in the emerging Tarascan state

This study presents compositional data from ceramics drawn from surface survey and controlled excavations from three prehispanic sites within the relatively small Lake Pátzcuaro Basin, representing a ceramic sequence stretching nearly 1500 years, from the Preclassic to Late Postclassic Tarascan state (ca. 50 B.C.–1525 A.D.). Using neutron activation analysis, we identify compositional groups and model the importance of volcanic materials as temper in the construction of prehispanic ceramics by matching mathematical simulations of clay–ash mixes to the compositional groups. Rather than discreet clay resources and spatially circumscribed production, we argue for a broadly dispersed and highly varied organization of pre-Tarascan and Tarascan state ceramic production in which the potters' distribution and use of specific volcanic ashy additives, not clays, structured the organization of production.     

Scale, causality, complexity and emergence: rethinking scale's ontological significance

Scale remains a pivotal yet highly contentious concept in geography. I survey the lively discussions engaged in recently by many critical/radical geographers regarding the theoretical status of scale. While these discussions have been intellectually fruitful, I argue that much more needs to be said. Drawing from complex systems theory, I argue that scale should be understood as an ontological category essential to understanding causality. Revalorising Aristotle's four categories of cause – formal, final, material and efficient – from two centuries of positivist thinking facilitates this endeavour. Research on the relationship between university-based poultry scientists and the poultry industry illustrates the explanatory potential of poly-scalar analysis.     

Local and nonlocal knowledge typologies: technological complexity in the Irish knowledge space

This paper advances a measure of knowledge complexity to analyse for Ireland whether more complex knowledge is generated by local or foreign firms. Information on assignees, technological structure and global ownership contained within a recently developed Irish patent database forms the basis for distinguishing between technologies developed by local and nonlocal firms. Thereafter, our knowledge complexity index uses a modified bipartite network to link these technologies to their country of origin, i.e. local or nonlocal. Our results indicate that the most complex technologies tend to be produced in a few diverse regions. Furthermore, the majority of complex knowledge is generated in technology classes where the share of foreign activity is greater than local firms.     

Development of a systems model to visualise the complexity of children's independent mobility

Substantial changes to the built environment, urbanisation patterns, and societal norms have contributed to limiting children's opportunities for being independently mobile. Several linear causal pathway models have been developed to understand the influences on children's independent mobility; however feedback loops between and within the various levels of influence cannot be modelled using such an approach. The purpose of this paper is to refine the interrelationships of factors related to children's independent mobility, taking into account earlier models, broader contextual factors, recent children's geographies literature, and feedback loops. Systems model components were informed by attributes known to influence children's independent mobility, related qualitative findings, and the development of a framework that could lend itself to multilevel modelling approaches. This systems model may provide a useful structure for identifying how best to develop and monitor interventions to halt the declining rates of children's independent mobility.     

Scientific knowledge production in European regions: patterns of growth,diversity and complexity

ABSTRACT

We study regional patterns of scientific knowledge production in Europe using all scientific publications in the period 2000–2014 attributed to 813 scientific subfields. We show that the existing scientific portfolio of regions offers opportunities for related diversification and discourages the creation of knowledge on topics unrelated to the local knowledge base. Many lagging regions show clear growth, but complex knowledge production remains highly concentrated in regions in the North and West of Europe. For lagging regions there are advantages in not specializing too soon and to first diversify before moving into developing more complex knowledge.     

Engagement: Archaeological Design and Engineering

Practice, architectonics, the disposition of materials, instruments, people, the articulation of heterogeneous parts in an assemblage that performs transformative work: we can easily call this engineering—science in action. One of the main topics of this collection of papers is the design of archaeological knowledge. Taking a lead from these papers, let us ask how we might work with the richness of the past, creatively, respecting the qualities of materials and relationships. From these questions, I sketch a few components in the design of knowledge.     

Spider Webs: Design and Engineering

Abstract

‘All things in nature,’ said Sullivan, have a shape, that is to say, a form, an outward semblance, that tells us what they are that distinguishes them from ourselves and from each other ….'. ‘Whether it be the sweeping eagle in his flight or the open apple-blossom, the toiling work-horse, the blithe swan, the branching oaks, the drifting clouds, over all the coursing sun, form ever follows function, and this is the law.’     

工程遗产初探

工程遗产不同于古建筑,也不同于工业遗产。中国的古代工程遗产具有独特的科学技术价值、集成价值和发展价值。然而工程遗产实物难于辨识,遗产价值易被忽视,遗产性质和遗产构成难于界定,遗产真实性难于评估,遗产保护和展示难度大,因此长期以来重视程度不够。我们需要加强基础研究,并争取政策支持和开放合作,以实现对工程遗产的整体保护。     

The evolution of sociopolitical complexity in prehistoric Hawaii: An assessment of the archaeological evidence

The sociopolitical system of late prehistoric Hawaii was among the most complex of any Oceanic chiefdom, as indexed by such characteristics as scale, rate of energy extraction, degree of functional specialization, and political hierarchy. Various anthropologists and archaeologists have advanced models of how this complex sociopolitical system developed out of an earlier Ancestral Polynesian society. Recent advances in Hawaiian archaeology have now begun to provide a wealth of data on the course of prehistoric change in the archipelago over some 1500 years and, thus, provide evidence which can be used to test alternative models of the evolution of sociopolitical complexity. This paper reviews the major alternative models that have been put forward and provides a synopsis of the archaeological evidence relevant to their testing.     

Mapungubwe and Great Zimbabwe: The origin and spread of social complexity in southern Africa

Stratified societies in southern Africa first developed in the Shashe–Limpopo Basin. As is well known, rank-based society at K2 developed into class distinction at Mapungubwe. The transfer of this new social organisation to Great Zimbabwe has received less attention. New research on rainmaking practices suggests that a Mapungubwe dynasty introduced class structures at Great Zimbabwe. Poor climatic conditions at the end of the 13th century undermined sacred leaders at Mapungubwe itself, and while vulnerable, the elite at Great Zimbabwe took over the important gold and ivory trade. Among other things, the new elite used the unique Zimbabwe birdstones to establish their legitimacy.     

Sr/Sr variability in Puerto Rico: geological complexity and the study of paleomobility

The temptation to use biogeochemical techniques to resolve issues of paleomigration is evident and well intentioned. Knowledge of radiogenic strontium isotope baselines in a region of interest is a sine qua non of such archaeological studies of paleomobility. Here, we present the first detailed study of baseline ⁸⁷Sr/⁸⁶Sr values for the island of Puerto Rico. The high degree of ⁸⁷Sr/⁸⁶Sr variability present in this corpus of modern Puerto Rican bedrock and terrestrial malacological samples (0.70406–0.70909) is a testament to the complex geology of that island. This diversity of ⁸⁷Sr/⁸⁶Sr values makes parsing issues of origin a difficult and highly contingent task. Given these complexities, regional studies seeking to assess paleomigration by such isotopic means should proceed with a great deal of caution.     

Engineering as a Source of Scientific Ideas

Abstract

Engineering has discovered some laws of nature as limits to what can be done, from which have developed the sciences of thermodynamics, information theory and cybernetics. Considered as a science, engineering lies between physics and biology, because its machines have physical structures and properties but biological organizations and functions. The old idea of the living body as an engine retains its power in modern biology; and the reconsideration of various natural non-biological processes in terms of engineering and biological concept reveals inadequacies in modern physical theory.     

More than trees: The challenges of creating a geodatabase to capture the complexity of forest history

European forests have been copiously documented for centuries. However, forest-related archival sources were rarely utilised to their full potential, mainly because of the difficulties in producing compatible data from large amounts of very different sources. Furthermore, analysing such data for larger areas in high resolution was hardly possible prior to the emergence of historical GIS. This paper presents the geodatabase of the LONGWOOD project, which includes tens of thousands of pieces of information on forest history from the 11^th to the 20^th century for 3,567 townships in the eastern Czech Republic (c. 27,000 km²). The paper describes the challenges we met, briefly summarizes the results, evaluates the database in a worldwide context and introduces possible directions for future research.