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Dynamic response of support systems during excavation of underground openings

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第5期11卷 954-964页

作者： ?.Aydan Department of Civil Engineering University of Ryukyus

Rockburst,earthquake and blasting cause some dynamic loads on rock support and rock reinforcement *** of rock support and rock reinforcement are generally made of steel bar or cables,which are resistant against *** support elements may be subjected to vibrations induced by turbines,vehicle traffic and long-term corrosion in addition to dynamic loading caused by earthquake,rockburst and *** this study,some theoretical,numerical and experimental studies are conducted on rockbolts and rock anchors under shaking and impulsive *** the outcomes of these studies are presented and their practical implications are discussed accordingly.

关键词： Rockbolt Dynamic behaviour Pull-out test Planar sliding Underground openings Slopes

Periodical zonal character of damage near the openings inhighly-stressed rock mass conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 164-169页

作者： Vladimir VMakarov Mikhail AGuzev Vladimir NOdintsev Lyudmila SKsendzenko Far-Eastern Federal University VladivostokRussia Russian Academy of Sciences MoscowRussia

Rock mass damage at great depths near underground openings is often of a zonal ***,the classical elastoplastic theory fails to explain sufficiently all properties of zonal failure structures.A new non-Euclidean mathematical model for highly-stressed rock mass was developed based on the principles of mechanics of defected material and non-equilibrium *** were developed to determine model parameters that provide satisfactory correspondence between the experimental findings concerning faulted zonal structures near openings at great depths and mathematical *** mechanism of this phenomenon was discovered which consisted in a periodical character of stresses in the surrounding rock mass and development of tensile macrocracks at zones of maximal tangential *** relationships between the cracking zone width and rock mass strength were established.

关键词： Rock failure openings Zones Modeling

Finite Element Modelling of Steel Beams with Web openings

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Engineering（科研） 2014年第13期6卷 886-913页

作者： Flavio Rodrigues Pedro C. G. da S. Vellasco Luciano R. O. de Lima Sebastiã o A. L. de Andrade PGECIV—Post Graduate Program in Civil Engineering UERJ—State University of Rio de Janeiro Rio de Janeiro Brazil Structural Engineering Department UERJ—State University of Rio de Janeiro Rio de Janeiro Brazil

Height limitations are not uncommon in multi-storey buildings due to economic requirements and esthetical considerations. Substantial spaces are normally required to enable the passage of large pipes and ducts beneath steel beams leading to uneconomic floor heights. The most adopted solution for this issue is the use of steel beam web openings to provide the required space for services. These openings could lead to a significant decrease of the beam load carrying capacity depending on the adopted openings shape, size and location. These aspects motivated the present study based on FE simulations calibrated against numerical and test results. The results accuracy enabled a comprehensive parametric analysis of beams with web openings to be made focused on the profile size, web opening location, among others. The study also investigated the efficiency of longitudinal stiffeners welded at the opening region and benefits of using an adequate edge concordance radius in beams with rectangular and square openings. The obtained results showed the need of using welded longitudinal stiffeners in order to increase the beams ultimate load carrying capacity. This adoption can double or even triple the ultimate load of beams with rectangular and square opening heights equal to 0.75 H, respectively.

关键词： Non-Linear Analysis Steel Structures Web openings Steel Design and Behavior Finite Element Method

A Study on the Structural Response of a PSC Inner Containment Dome with Large openings Due to Prestress Transfer

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World Journal of Nuclear Science and Technology 2014年第2期4卷 103-122页

作者： Anirudh A. Desai Sekhar K. Chakrabarti Department of Civil Engineering Indian Institute of Technology Kanpur India

A linear three dimensional finite element (FE) study has been carried out to examine the structural response of a prestressed concrete (PSC) inner containment (IC) dome of reactor building (double containment system) of a typical Indian Nuclear Power Plant, having large steam generator (SG) openings with due emphasis on the local behaviour of the steel-concrete interfaces at the SG openings, due to initial prestress transfer. The predominant thrust of the study has been placed on the objective of predicting the possibilities of separation at the steel-concrete interface zones adjacent to the embedded plates (EPs) of the SG openings. Two types of modeling and analysis have been made to study the overall and local behaviour of the structure. Prestressing ducts, passive reinforcements and EPs have been included in the models in certain ways. For the FE analysis, the interface zone has been modeled using interface elements, the properties of which were derived from the results of past experiments conducted on steel plate-concrete inter-face specimens. The FE analysis results have been compared with the results of the past two FE analytical studies on the linear behaviour of the same PSC IC dome. Important observations have been made regarding dome deformation and stresses throughout the structure with special emphasis on the local behaviour of steel-concrete interfaces at and around the SG openings.

关键词： Prestressed Concrete Inner Containment Reactor Building Double Containment System Steel-Concrete Interface Steam Generator openings Steel Embedded Plates

A Theoretical Study the Effect of openings in Infill Wall Panels on the Behavior of Structures

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Journal of Southeast University(English Edition) 1998年第1期14卷 98-101页

作者： Umary Jamal College of Civil Engineering Southeast UniversityNanjing 210096

Two dimensional,reinforced concrete building frames built on raft foundation and having infill wall panels with openings in them are analysed using the direct stiffness *** and columns are modelled by beam column *** panels are modelled by plane stress finite *** raft foundation is modelled by uniaxial finite *** soil is modelled as half space *** in wall panels are introduced by using fictitious beams between real floor beams. A computer program is written to carry out the static analysis and do the necessary comparison to show the effect of openings on the structural behavior.

关键词： infill wall panels openings direct stiffness method horizontal displacement static seismic

3-D dynamic analysis for functionally graded material plates with different openings

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3-D dynamic analysis for functionally graded material plates...

Sensor location in concrete slabs with various layout of opening using modified ‘FEMS-COMAC’ approach

2011 International Conference on Smart Materials and Nanotechnology in Engineering (SMNE 2011)

作者： Yu You Zhen Sun Yi Qun Xu Zhou TIAND Heavy-duty Machinery Manufacturing CO.LTD.

The problems of functionally graded materials are supposed to be studied incorporating their microstructures. The microelement method proposed here is characterized by this capability. In this work, by using the Fortran source program of microelement method established on the basis of existing finite element method, 3-D dynamic analysis of functionally graded material plates with different openings is performed. It can be known from the numerical results that the shapes and number of openings have a significant influence on natural frequency and basic vibration modes of functionally graded material plates, which is different from the results of homogeneous plates. These results are significant to applications of functionally graded material plates with openings.

关键词： functionally graded material three-dimensional dynamic analysis microelement material component openings

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Earthquake Engineering and Engineering Vibration 2020年第1期19卷 205-222页

作者： H.Vosoughifar P.Manafi Department of Civil and Environmental Engineering University of Hawaii at ManoaHonoluluUSA Department of Civil Engineering South Tehran BranchIslamic Azad UniversityTehranIran

Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most important issue in structural health monitoring(SHM) to increase reliability. In this study, a novel approach of OSP was evaluated to obtain the number and placement of sensors using examination of the closed loop performance. The nonlinear finite element(NFE) was used to discretize the mechanism behavior of slab. Multi-Objective Optimization based on the coordinate modal assurance criterion(COMAC) and cost considerations was considered in the optimization processes. All of the analysis, discretization and optimization process was designed and developed as a novel approach in Matlab by the author under the name ‘FEMS-COMAC’(FEM analysis of slab with COMAC). The points in the finite element method(FEM) mesh were classified as line by line information along the slab. The OSP in each line was optimized according to the objective function. The slabs with various width, thickness, aspect ratio and opening position were selected as case studies. The results of the OSP using the COMAC algorithm around the slab openings were compared with the novel ‘FEMS-COMAC’ method. The statistical analysis according Mann-Whitney criteria shows that there were significant differences between them in some of the case studies(mean P-value=0.54).

关键词： two-way concrete slabs openings OSP MAC COMAC

Numerical simulation of roof cavings in several Kuzbass mines using finite-difference continuum damage mechanics approach

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International Journal of Mining Science and Technology 2020年第2期30卷 157-166页

作者： Mikhail Eremin Gabriel Esterhuizen Igor Smolin Institute of Strength Physics and Materials Science Siberian BranchRussian Academy of SciencesTomsk 634055Russian Federation National Institute for Occupational Safety and Health PittsburghPA 15236USA National Research Tomsk State University Tomsk 634050Russian Federation

An essential stage of mine design is an estimation of the steps of the first and periodic roof caving in longwall ***,this is carried out using the field experience and can be much enhanced by numerical *** this work,the finite-difference method was applied coupled with the continuum damage mechanics(CDM)approach to simulate the stress-strain evolution of the rock mass with the underground opening during coal *** steps and stages of roof caving were estimated relying on the numerical simulation data,and they were compared with the field data from several operating mines in the south of the Kuznetsk Basin,*** dependence of the first roof caving step in simulation linearly correlates with field *** results correspond to the actual roofs of longwall panels of the flat-dipping coal seams and the average rate of face advancement is approximately 5 m/day.

关键词： Longwall mining Rock mass Underground openings Roof caving Abutment pressure Numerical simulation

Quantifying the thermal damping effect in underground vertical shafts using the nonlinear autoregressive with external input(NARX) algorithm

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International Journal of Mining Science and Technology 2019年第2期29卷 255-262页

作者： Pedram Roghanchi Karoly C.Kocsis Mineral Engineering Derpartment New Mexico Institute of Mining and Technology Mining Engineering Derpartment University of Nevada

As air descends the intake shaft, its infrastructure, lining and the strata will emit heat during the night when the intake air is cool and, on the contrary, will absorb heat during the day when the temperature of the air becomes greater than that of the strata. This cyclic phenomenon, also known as the "thermal damping effect" will continue throughout the year reducing the effect of surface air temperature variation. The objective of this paper is to quantify the thermal damping effect in vertical underground airways. A nonlinear autoregressive time series with external input(NARX) algorithm was used as a novel method to predict the dry-bulb temperature(Td) at the bottom of intake shafts as a function of surface air temperature. Analyses demonstrated that the artificial neural network(ANN) model could accurately predict the temperature at the bottom of a shaft. Furthermore, an attempt was made to quantify typical "damping coefficient" for both production and ventilation shafts through simple linear regression models. Comparisons between the collected climatic data and the regression-based predictions show that a simple linear regression model provides an acceptable accuracy when predicting the Tdat the bottom of intake shafts.

关键词： Underground mining Vertical openings Thermal damping effect Artificial neural network Nonlinear autoregressive with external input(NARX)