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International Journal of Sediment Research 2018年第4期33卷 385-394页

作者： Szczepan Ludwik Dabkowski Lukasz Bak department of Water Quality Institute of Technology and Life Sciences department of geotechnics Geomatics and Waste Management Kielce University of Technology

A knowledge of the quantity of the sand fraction in the sediments deposited in reservoirs makes it easier to determine the bedload transport, which is a rarely measured parameter. The current study discusses the results of investigations into the siltation and physical properties of sediment in two small reservoirs located in the southeastern part of Poland. Also, the quantity of the bedload sand fraction was *** estimation of the reservoir capacity loss after t years of operation was based on hydroacoustic measurements. The sediment density, organic matter content, and granulometric composition were evaluated by means of investigations and analyses of bottom sediment core samples. The interpolation of the parameters describing the sediment properties was done using the Kriging method. The analyses indicate that 10.80 thousand m3of sediment were deposited into the Zalew Kielecki Reservoir in the years 2004-2015. Their overall mass was 7320 t, of which sand fraction sediments constituted 39.7%.Between the years 2004 and 2014, the Umer Reservoir retained 11.79 thousand m3of sediment having a mass of 7200 t, of which sand fraction constituted 34.6%.

关键词： Reservoir Sedimentation Bottom sediment properties Bedload transport Bathymetry

A mathematical model of gas flow during coal outburst initiation

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International Journal of Mining Science and Technology 2019年第5期29卷 791-796页

作者： Dmytro Rudakov Valeriy Sobolev department of Hydrogeology and Engineering Geology National Mining UniversityDnipro 49005Ukraine department of Construction Geotechnics and GeomechanicsNational Mining UniversityDnipro 49005Ukraine

A proposed concept of outburst initiation examines the release of a large amount of gas from coal seams resulted from disintegrating thermodynamically unstable coal organic matter(COM).A coal microstructure is assumed to getting unstable due to shear component appearance triggered by mining operations and tectonic activities considered as the primary factor while COM disintegration under the impact of weak electric fields can be defined as a secondary *** energy of elastic deformations stored in the coal microstructure activates chemical reactions to tilt the energy balance in a“coal–gas”*** on this concept a mathematical model of a gas flow in the coal where porosity and permeability are changed due to chemical reactions has been *** this model we calculated gas pressure changes in the pores initiated by gas release near the working face till satisfying force and energy criteria of *** simulation results demonstrated forming overpressure zone in the area of intensive gas release with enhanced porosity and *** calculated outburst parameters are well combined with those evaluated by field measurements.

关键词： Coal organic matter Coal meta-stability Outburst Gas flow Permeability Modeling

Fuzzy-entropy based robust optimization criteria for tuned mass dampers

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Earthquake Engineering and Engineering Vibration 2010年第2期9卷 285-294页

作者： Giuseppe Carlo Marano Giuseppe Quaranta Sara Sgobba department of Environmental Engineering and Sustainable Development Technical University of Bari department of Structural Engineering and geotechnics University of Rome "La Sapienza" Faculty of Engineering International University UNINETTUNO

Tuned mass dampers (TMD) are well known as one of the most widely adopted devices in vibration control passive strategies. In the past few decades,many methods have been developed to find the optimal parameters of a TMD installed on a structure and subjected to a random base excitation process,but most of them are usually based on an implicit assumption that all of the structural parameters are deterministic. However,in many real cases this simplification is unacceptable,so robust optimal design criteria becomes aviable alternative to better support engineers in the design process. In Robust Design Optimization (RDO) approaches,indeed the solution must be able to not only minimize the performance but also to limitits variation induced by uncertainty. Most of the currently available RDO methods are based on a probabilistic description of the model uncertainty,even if in many cases they are not able to explicitly include the influence of all the possible sources of uncertainties. Therefore,in this study,a fuzzy version of the robust TMD design optimization problem is proposed. The consistency of the fuzzy approach is studied with respect to the available non-probabilistic formulations reported in the literature and an application to an example of a robust design of a linear TMD subjected to base random vibrations in the presence of fuzzy uncertainties. The results show that the proposed fuzzy-based approach is able to give a set of optimal solutions both in terms of structural efficiency and sensitivity to mechanical and environmental uncertainties.

关键词： tuned mass damper random vibration robust design fuzzy variable expected value fuzzy entropy

Influence of loading and heating processes on elastic and geomechanical properties of eclogites and granulites

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 127-137页

作者： Hem Bahadur Motra Sascha Zertani department of Geosciences Marine and Land Geomechanics and Geotechnics University of Kiel Institut für Geologische Wissenschaften Freie Universitat Berlin

Increased knowledge of the elastic and geomechnical properties of rocks is important for numerous engineering and geoscience applications(e.g. petroleum geoscience, underground waste repositories,geothermal energy, earthquake studies, and hydrocarbon exploration). To assess the effect of pressure and temperature on seismic velocities and their anisotropy, laboratory experiments were conducted on metamorphic rocks. P-(Vp) and S-wave(Vs) velocities were determined on cubic samples of granulites and eclogites with an edge length of 43 mm in a triaxial multianvil apparatus using the ultrasonic pulse emission technique in dependence of changes in pressure and temperature. At successive isotropic pressure states up to 600 MPa and temperatures up to 600 ℃, measurements were performed related to the sample coordinates given by the three principal fabric directions(x, y, z) representing the foliation(xy-plane), the normal to the foliation(z-direction), and the lineation direction(x-direction). Progressive volumetric strain was logged by the discrete piston displacements. Cumulative errors in Vpand Vsare estimated to be <1%. Microcrack closure significantly contributes to the increase in seismic velocities and decrease in anisotropies for pressures up to 200-250 MPa. Characteristic P-wave anisotropies of about 10% are obtained for eclogite and 3-4% in a strongly retrogressed eclogite as well as granulites. The wave velocities were used to calculate the geomechanical properties(e.g. density, Poisson’s ratio, volumetric strain, and elastic moduli) at different pressure and temperature conditions. These results contribute to the reliable estimate of geomechanical properties of rocks.

关键词： Anisotropy Elastic wave velocities Dynamic elastic moduli Geomechanical rock properties Microcrack

A New Dynamic and Vertical Photovoltaic Integrated Building Envelope for High-Rise Glaze-Facade Buildings

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Engineering 2024年第8期39卷 194-203页

作者： Wuwei Zou Yan Wang Enze Tian Jiaze Wei Jinqing Peng Jinhan Mo College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Department of Building ScienceSchool of ArchitectureTsinghua UniversityBeijing 100084China Songshan Lake Materials Laboratory Dongguan 523808China Institute of Physics Chinese Academy of SciencesBeijing 100190China College of Civil Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Intelligent geotechnics and Tunnelling Shenzhen 518060China Key Laboratory of Coastal Urban Resilient Infrastructures Ministry of EducationShenzhen UniversityShenzhen 518060China Key Laboratory of Eco Planning&Green Building Ministry of EducationTsinghua UniversityBeijing 100084China

Substantially glazed facades are extensively used in contemporary high-rise buildings to achieve attractive architectural *** conflicts exist among architectural aesthetics,building energy consumption,and solar energy harvesting for glazed *** this study,we addressed these conflicts by introducing a new dynamic and vertical photovoltaic integrated building envelope(dvPVBE)that offers extraordinary flexibility with weather-responsive slat angles and blind positions,superior architectural aesthetics,and notable energy-saving *** hierarchical control strategies were proposed for different scenarios of the dvPVBE:power generation priority(PGP),natural daylight priority(NDP),and energy-saving priority(ESP).Moreover,the PGP and ESP strategies were further analyzed in the simulation of a *** office room integrated with a dvPVBE was modeled using *** influence of the dvPVBE in improving the building energy efficiency and corresponding optimal slat angles was investigated under the PGP and ESP control *** results indicate that the application of dvPVBEs in Beijing can provide up to 131%of the annual energy demand of office rooms and significantly increase the annual net energy output by at least 226%compared with static photovoltaic(PV)*** concept of this novel dvPVBE offers a viable approach by which the thermal load,daylight penetration,and energy generation can be effectively regulated.

关键词： Weather-responsive facades Building energy efficiency Dynamic photovoltaic integrated building envelopes(PVBEs) Building-integrated photovoltaics(BIPVs)

Multifaceted Bioinspiration for Improving the Shaft Resistance of Deep Foundations

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Journal of Bionic Engineering 2020年第5期17卷 1059-1074页

作者： Seyed Ali Aleali Paola Bandini Craig Michael Newtson Center for Bio-mediated and Bio-inspired geotechnics Department of Civil EngineeringNew Mexico State UniversityLas CrucesNew Mexico 88003-8001USA

This paper describes the bioinspiration process to derive design concepts for new deep foundation systems that have greater axial capacity per unit volume of pile material compared to conventional deep *** study led to bioinspired ideas that provide greater load capacity by increasing the pile shaft *** bioinspiration approach used problem-solving strategies to define the problem and transfer strategies from biology to geotechnical *** bioinspiration considered the load transfer mechanism of hydroskeletons and the anchorage of the earthworm,razor clam,kelp,and lateral roots of *** biostrategies that were transferred to the engineering domain included a flexible but incompressible core,passive behaviour against external loading,a longitudinally split shell that allows expansion for anchorage,and lateral root-type or setae-type anchoring *** concepts of three bioinspired deep foundation systems were proposed and *** advantage of this approach was illustrated with two examples of the new laterally expansive pile in drained sand under axial *** finite element analysis of these examples showed that the new laterally expansive pile can provide considerably greater load capacity compared to a conventional cylindrical pile due to the increased lateral confining pressure developed along the expanded pile core.

关键词： bioinspiration expansion anchorage deep foundation pile capacity frictional resistance

Optimum Heating of Thick-Walled Pressure Components Assuming a Quasi-steady State of Temperature Distribution

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Journal of Thermal Science 2016年第4期25卷 380-388页

作者： Piotr Dzierwa Marcin Trojan Dawid Taler Katarzyna Kamińska Jan Taler Institute of Thermal Power Engineering Cracow University of Technology Institute of Thermal Engineering and Air Protection Faculty of Environmental Engineering department of Hydraulic Engineering and geotechnics Agricultural University of Cracow

As a result of the development of wind farms,the gas- steam blocks,which shall quickly ensure energy supply in case the wind velocity is too low,are introduced to the energy *** shorten the start-up time of the gas-steam and conventional blocks,the structure of the basic components of the blocks are changed,*** reducing the diameter of the boiler,the thickness of its wall is also *** attempts were also made to revise the currently binding TRD 301 regulations,replacing them by the EN 12952-3 European Standard,to reduce the allowable heating and cooling rates of thick walled boiler *** basic assumption,on which the boiler regulations allowing to calculate the allowable temperature change rates of pressure components were based,was the quasi- steady state of the temperature field in the simple shaped component,such as a slab,cylindrical or spherical wall.

关键词： pressure component thermal stress quasi-steady state optimum heating

Influence of heterogeneity on rock strength and stiffness using discrete element method and parallel bond model

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 575-584页

作者： Spyridon Liakas Catherine O’Sullivan Charalampos Saroglou Arup geotechnics Solihull UK department of Civil & Environmental Engineering Imperial College London London UK department of Geotechnical Engineering School of Civil Engineering National Technical University Athens Athens Greece

The particulate discrete element method(DEM) can be employed to capture the response of rock,provided that appropriate bonding models are used to cement the particles to each *** of laboratory tests are important to establish the extent to which those models can capture realistic rock *** the focus in such comparison studies has either been on homogeneous specimens or use of two-dimensional(2D) *** situ rock formations are often heterogeneous,thus exploring the ability of this type of models to capture heterogeneous material behavior is important to facilitate their use in design *** situ stress states are basically three-dimensional(3D),and therefore it is important to develop 3D models for this *** paper revisits an earlier experimental study on heterogeneous specimens,of which the relative proportions of weaker material(siltstone) and stronger,harder material(sandstone) were varied in a controlled *** a 3D DEM model with the parallel bond model,virtual heterogeneous specimens were *** overall responses in terms of variations in strength and stiffness with different percentages of weaker material(siltstone) were shown to agree with the experimental *** was also a good qualitative agreement in the failure patterns observed in the experiments and the simulations,suggesting that the DEM data enabled analysis of the initiation of localizations and micro fractures in the specimens.

关键词： Discrete element method(DEM) Heterogeneous rocks Strength and stiffness Parallel bond model

Monotonic, cyclic and post-cyclic performances of single-helix anchor in residual soil of sandstone

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第4期11卷 824-836页

作者： Jose Antonio Schiavon Cristina de Hollanda Cavalcanti Tsuha Luc Thorel department of Geotechnical Engineering Aeronautics Institute of TechnologySao Jose dos CamposBrazil department of Geotechnical Engineering University of Sao PauloSao CarlosBrazil IFSTTAR GERS DepartmentGeomaterials & Models in Geotechnics LaboratoryBouguenaisFrance

Helical anchors are commonly used in Brazil for guyed transmission towers subjected to static and cyclic wind *** most cases,these anchors are installed in tropical residual soil,a micro-structured material in which the shear strength is provided by soil *** installation of a helical anchor,as the helical plate moves downward into the ground,the soil penetrated is sheared and ***,in this type of soil,anchor installation affects the soil shear strength significantly associated with a bonded ***,the cyclic responses of helical anchors in this type of structured soils are rarely *** address this problem,tests were conducted in a Brazilian residual soil to investigate the monotonic,cyclic and post-cyclic performances of single-helix *** tests used two instrumented single-helix anchors installed in this typical residual soil of sandstone,which is frequently observed in large areas in the southern *** testing results indicate that the disturbance caused by the anchor installation affected the monotonic uplift performance *** results of cyclic loading tests also show no significant degradation of helix bearing resistance and reduced displacement accumulation with increasing load *** is perhaps due to the soil improvement caused by previous loading,which then increases the stiffness response of the anchor.

关键词： Helical anchors Tropical residual soil Cyclic loading Field load tests

Ultimate bearing capacity of strip footing resting on clay soil mixed with tire-derived aggregates

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Frontiers of Structural and Civil Engineering 2021年第4期15卷 1016-1024页

作者： Ali AREFNIA Ali DEHGHANBANADAKI Khairul Anuar KASSIM department of geotechnics&Transportation School of Civil EngineeringFaculty of EngineeringUniversiti Teknologi MalaysiaSkudai81310Malaysia department of Civil Engineering Roudehen BranchIslamic Azad UniversityTehranIran department of Civil Engineering Damavand BranchIslamic Azad UniversityDamavandTehranIran

This study investigated the use of recycled tire-derived aggregate(TDA)mixed with kaolin as a method of increasing the ultimate bearing capacity(UBC)of a strip *** 1g physical modeling tests were prepared in a rigid box of 0.6 m×0.9 m in plan and 0.6 m in *** sample preparation,0%,20%,40%,or 60%(by weight)of powdery,shredded,small-sized granular(G 1–4 mm)or large-sized granular(G 5–8 mm)TDA was mixed with the kaolin.A strip footing was then placed on the stabilized kaolin and was caused to fail under stress-controlled conditions to determine the UBC.A rigorous 3D finite element analysis was developed in Optum G-3 to determine the UBC values based on the experimental test *** experimental results showed that,except for the 20%powdery TDA,the TDA showed an increase in the UBC of the strip *** kaolin mixed with 20%G(5–8 mm),the UBC showed a threefold increase over that for the unreinforced *** test with 20%G(1–4 mm)recorded the highest subgrade *** was observed that the UBC calculated using finite element modeling overestimated the experimental UBC by an average of 9%.

关键词： kaolin physical modeling tests stabilization numerical modeling