Structural control considering soil–structure interaction effects     

H. Allison Smith  Wen-Hwa Wu  Ronaldo I. Borja 《地震工程与结构动力学》1994,23(6):609-626

A discussion of the effects of Soil-Structure Interaction (SSI) on the formulation of active structural control algorithms is presented. Two approaches for incorporating SSI effects in linear optimal control theory are developed: one which performs the control analysis on a structure with a fixed base and then considers the effects of SSI on the controlled structural response; and another which performs the control analysis using a structural equation of motion reformulated to include SSI effects. The two control formulations are studied and compared using a single-degree-of-freedom structure supported through a rigid foundation resting on a linear, elastic half-space. Results show that control effectiveness is affected by the approach used in formulating the equations of motion of the interacting system.  相似文献   

Aggregation-based information retrieval system for geospatial data catalogs     

Javier Lacasta  F. Javier Lopez-Pellicer  Borja Espejo-García  Javier Nogueras-Iso  F. Javier Zarazaga-Soria 《International journal of geographical information science》2017,31(8):1583-1605

Geospatial data catalogs enable users to discover and access geographical information. Prevailing solutions are document oriented and fragment the spatial continuum of the geospatial data into independent and disconnected resources described through metadata. Due to this, the complete answer for a query may be scattered across multiple resources, making its discovery and access more difficult. This paper proposes an improved information retrieval process for geospatial data catalogs that aggregates the search results by identifying the implicit spatial/thematic relations between the metadata records of the resources. These aggregations are constructed in such a way that they match better the user query than each resource individually.  相似文献   

The application of Hert'z contact theory to the problem of an offshore structure entering the seabed     

V Birman  R Latorre 《Ocean Engineering》1985,12(4):369-373

This paper treats the problem of the penetration of a cylindrical leg of a fixed offshore structure into the sea. The problem is taken as a classic contact problem where the seabed is flat and two cases of structure geometry are considered. Comparisons of the flat and hemispherical bottom geometries indicate that the hemispherical geometry requires 2/3 the load of the flat bottom. This results leads to a preliminary conclusion that a hemispherical geometry is more efficient for initial penetration.  相似文献   

Relationships between wave exposure and biomass of the goose barnacle (Pollicipes pollicipes, Gmelin, 1790) in the Gaztelugatxe Marine Reserve (Basque Country, northern Spain)     

Borja  Angel; Liria  Pedro; Muxika  Inigo; Bald  Juan 《ICES Journal of Marine Science》2006,63(4):626-636

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A double-yield-surface plasticity theory for transversely isotropic rocks     

Zhao  Yang  Borja  Ronaldo I. 《Acta Geotechnica》2022,17(11):5201-5221

Acta Geotechnica - We present a double-yield-surface plasticity theory for transversely isotropic rocks that distinguishes between plastic deformation through the solid matrix and localized...  相似文献   

Poroelastic coefficients for anisotropic single and double porosity media     

Zhang  Qi  Borja  Ronaldo I. 《Acta Geotechnica》2021,16(10):3013-3025

Acta Geotechnica - Closed-form expressions for poroelastic coefficients are derived for anisotropic materials exhibiting single and double porosity. A novel feature of the formulation is the use of...  相似文献   

A Marine Biotic Index to Establish the Ecological Quality of Soft-Bottom Benthos Within European Estuarine and Coastal Environments   总被引：34，自引：0，他引：34  

A. Borja  J. Franco  V. Prez 《Marine pollution bulletin》2000,40(12):1235-1114

In this paper, a marine Biotic Index (BI) for soft-bottom benthos of European estuarine and coastal environments is proposed. This is derived from the proportions of individual abundance in five ecological groups, which are related to the degree of sensitivity/tolerance to an environmental stress gradient. The main difference with previously published indices is the use of a simple formula that produces a continuous Biotic Coefficient (BC) – which makes it more suitable for statistical analysis, in opposition with previous discreet biotic indices – not affected by subjectivity. Relationships between this coefficient and a complementary BI with several environmental variables are discussed. Finally, a validation of the proposed index is made with data from systems affected by recent human disturbances, showing that different anthropogenic changes in the environment can be detected through the use of this BI.  相似文献   

Human impacts overwhelm the effects of sea-level rise on Basque coastal habitats (N Spain) between 1954 and 2004     

Guillem Chust  ngel Borja  Pedro Liria  Ibon Galparsoro  Marta Marcos  Ainhoa Caballero  Raúl Castro 《Estuarine, Coastal and Shelf Science》2009,84(4):453-462

According to coastal measurements, global mean sea-level has risen at a rate of 1.8 mm yr⁻¹ between 1950 and 2000, with large spatial variability at regional scales. Within the Bay of Biscay, trends computed from coastal tide gauges records have revealed that sea-level rise is accelerating over this period of time; this is in agreement with rates obtained from satellite imagery in the open ocean since 1993. The objectives of the present study are: (1) to assess the evidence of the relative sea-level rise on coastal morphology and habitats in the Gipuzkoan littoral zone (Basque coast, northern Spain) for the period 1954–2004, and (2) to evaluate the relative contribution of local anthropogenic versus sea-level rise impacts for explaining inter-supratidal habitat changes. A high-resolution airborne laser altimetry data (LIDAR) has been used to derive a Digital Terrain Model (DTM) of 15-cm vertical resolution. Coastal habitats were mapped for two periods, using historic airborne photography (1954) and high-resolution imagery (2004). Analysis of tide gauge records from Santander (northern Spain) has revealed that relative mean sea-level has been rising at a rate of 2.08 ± 0.33 mm yr⁻¹ from 1943 to 2004; this is consistent with sea-level trends from other measurements within the area (St. Jean de Luz and Bilbao), obtained over shorter periods of time, and with previous results obtained in the Bay of Biscay. Based upon this sea-level trend and by means of a LIDAR-based DTM, the results have indicated that the predicted change along the Gipuzkoan coast due to sea-level rise was of 11.1 ha within the 50-yr period. In contrast, comparison of historical and recent orthophotography has detected only 2.95 ha of change, originated possibly from sea-level rise, and 98 ha transformed by anthropogenic impacts. Hence, coastal changes due to sea-level rise might be overwhelmed by excessive human impacts, at the spatial and temporal scales of the analysis. This work highlights that local anthropogenic impact is the major threat to Basque coastal and estuarine habitats, compared with natural erosive processes and global climate change driving forces over recent times.  相似文献   

Micro-bubble resistance reduction on a model SES catamaran     

Robert Latorre  Aaron Miller  Richard Philips 《Ocean Engineering》2003,30(17):2297-2309

The concept of micro-bubble ejection is emerging as an attractive method for viscous drag reduction for high speed craft. Most of the drag reduction literature presents results for micro-bubble ejection above/below horizontal surfaces. Nevertheless, modern high-speed hull forms are slender with vertical surfaces. This paper presents results of model tests with micro-bubble ejection to the vertical sides of a high speed model with a non-wetting coating. The coating yielded drag reduction of 4–6% and micro-bubbles with coating reduced overall drag by 4–11%. The local coefficient of friction with micro-bubbles is analyzed and found comparable to vertical flat plate results of [Madavan et al., 1984].  相似文献   

Three- and four-term approximate expansions of the Haverkamp formulation to estimate soil hydraulic properties from disc infiltrometer measurements     

David Moret-Fernández  Borja Latorre  Maria V. López  Yolanda Pueyo  Laurent Lassabatere  Rafael Angulo-Jaramilo  Mehdi Rahmati  Jaume Tormo  José M. Nicolau 《水文研究》2020,34(26):5543-5556

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