42 research outputs found
Ductility of wide-beam RC frames as lateral resisting system
[EN] Some Mediterranean seismic codes consider wide-beam reinforced concrete moment resisting frames (WBF) as horizontal load carrying systems that cannot guarantee high ductility performances. Conversely, Eurocode 8 allows High Ductility Class (DCH) design for such structural systems. Code prescriptions related to WBF are systematically investigated. In particular, lesson learnt for previous earthquakes, historical reasons, and experimental and numerical studies underpinning specific prescriptions on wide beams in worldwide seismic codes are discussed. Local and global ductility of WBF are then analytically investigated through (1) a parametric study on chord rotations of wide beams with respect to that of deep beams, and (2) a spectral-based comparison of WBF with conventional reinforced concrete moment resisting frames (i.e. with deep beams). Results show that the set of prescriptions given by modern seismic codes provides sufficient ductility to WBF designed in DCH. In fact, global capacity of WBF relies more on the lateral stiffness of the frames and on the overstrength of columns rather than on the local ductility of wide beams, which is systematically lower with respect to that of deep beams.Gómez-MartÃnez, F.; Alonso Durá, A.; De Luca, F.; Verderame, GM. (2016). Ductility of wide-beam RC frames as lateral resisting system. Bulletin of Earthquake Engineering. 14(6):1545-1569. doi:10.1007/s10518-016-9891-xS15451569146ACI (1989) Building code requirements for reinforced concrete (ACI 318-89). ACI Committee 318, American Concrete Institute, Farmington Hills, Michigan, USAACI (2008) Building code requirements for structural concrete (ACI 318-08) and commentary (318-08). ACI Committee 318, American Concrete Institute, Farmington Hills, Michigan, USAACI-ASCE (1991) Recommendations for design of beam-column connections in monolithic reinforced concrete structures (ACI 352R-91). Joint ACI-ASCE Committee 352, American Concrete Institute, Farmington Hills, Michigan, USAACI-ASCE (2002) Recommendations for design of beam-column connections in monolithic reinforced concrete structures (ACI 352R-02). Joint ACI-ASCE Committee 352, American Concrete Institute, Farmington Hills, Michigan, USAArslan MH, Korkmaz HH (2007) What is to be learned from damage and failure of reinforced concrete structures during recent earthquakes in Turkey? Eng Fail Anal 14(1):1–22ASCE (2007) Seismic Rehabilitation of Existing Buildings, ASCE/SEI 41-06. American Society of Civil Engineers, RestonASCE (2010) Minimum Design Loads for Building and Other Structures, ASCE/SEI 7-10. American Society of Civil Engineers, RestonBenavent-Climent A (2007) Seismic behavior of RC side beam-column connections under dynamic loading. J Earthquake Eng 11:493–511Benavent-Climent A, Zahran R (2010) An energy-based procedure for the assessment of seismic capacity of existing frames: application to RC wide beam systems in Spain. Soil Dyn Earthq Eng 30:354–367Benavent-Climent A, CahÃs X, Zahran R (2009) Exterior wide beam-column connections in existing RC frames subjected to lateral earthquake loads. Eng Struct 31:1414–1424Benavent-Climent A, CahÃs X, Vico JM (2010) Interior wide beam-column connections in existing RC frames subjected to lateral earthquake loading. Bull Earthq Eng 8:401–420BHRC (2004) Iranian Code of Practice for Seismic Resistant Design of Buildings. Standard Nº 2800, 3rd edn. Building and Housing Research Center, TehranBorzi B, Elnashai AS (2000) Refined force reduction factors for seismic design. Eng Struct 22:1244–1260Borzi B, Pinho R, Crowley H (2008) Simplified pushover-based vulnerability analysis for large-scale assessment of RC buildings. Eng Struct 30:804–820BSI (2004) Eurocode 2: Design of concrete structures: Part 1-1: General rules and rules for buildings. British Standards Institutions, LondonCalvi GM (1999) A displacement-based approach for vulnerability evaluation of classes of buildings. J Earthquake Eng 3(3):411–438CDSC (1994) Seismic construction code, NCSR-94. Committee for the Development of Seismic Codes, Spanish Ministry of Construction, Madrid, Spain (in Spanish)CDSC (2002) Seismic construction code, NCSE-02. Committee for the Development of Seismic Codes, Spanish Ministry of Construction, Madrid, Spain (in Spanish)CEN (2004) Eurocode 8: design of structures for earthquake resistance—part 1: general rules, seismic actions and rules for buildings. European Standard EN 1998-1:2003—Comité Européen de Normalisation, Brussels, BelgiumCEN (2005) Eurocode 8: design of structures for earthquake resistance—part 3: assessment and retrofitting of buildings. European Standard EN 1998-1:2005—Comité Européen de Normalisation, Brussels, BelgiumCheung PC, Paulay T, Park R (1991) Mechanisms of slab contributions in beam-column subassemblages. ACI Spec Publ 123Cosenza E, Manfredi G, Polese M, Verderame GM (2005) A multilevel approach to the capacity assessment of existing RC buildings. J Earthquake Eng 9(1):1–22Crowley H, Pinho R (2010) Revisiting Eurocode 8 formulae for periods of vibration and their employment in linear seismic analysis. Earthquake Eng Struct Dynam 39:223–235CS.LL.PP (2009) Instructions for the application of the technique code for the Constructions. Official Gazette of the Italian Republic, 47, Regular Supplement no. 27 (in Italian)De Luca F, Vamvatsikos D, Iervolino I (2013) Near-optimal piecewise linear fits of static pushover capacity curves for equivalent SDOF analysis. Earthquake Eng Struct Dynam 42(4):523–543De Luca F, Verderame GM, Gómez-MartÃnez F, Pérez-GarcÃa A (2014) The structural role played by masonry infills on RC building performances after the 2011 Lorca, Spain, earthquake. Bull Earthq Eng 12(5):1999–2026Decanini LD, Mollaioli F (2000) Analisi di vulnerabilità sismica di edifici in cemento armato pre-normativa. In: Cosenza E (ed) Comportamento sismico di edifici in cemento armato progettati per carichi verticali. CNR—Gruppo Nazionale per la Difesa dei Terremoti, Rome (in Italian)DolÅ¡ek M, Fajfar P (2004) IN2—a simple alternative for IDA. In: Proceedings of the 13th World conference on Earthquake Engineering. August 1–6, Vancouver, Canada. Paper 3353DomÃnguez D, López-Almansa F, Benavent-Climent A (2014) Comportamiento para el terremoto de Lorca de 11-05-2011, de edificios de vigas planas proyectados sin tener en cuenta la acción sÃsmica. Informes de la Construcción 66(533):e008 (in Spanish)DomÃnguez D, López-Almansa F, Benavent-Climent A (2016) Would RC wide-beam buildings in Spain have survived Lorca earthquake (11-05-2011)? Eng Struct 108:134–154Dönmez C (2013) Seismic Performance of Wide-Beam Infill-Joist Block RC Frames in Turkey. J Perform Constr Facil 29(1):04014026Fadwa I, Ali TA, Nazih E, Sara M (2014) Reinforced concrete wide and conventional beam-column connections subjected to lateral load. Eng Struct 76:34–48Fardis MN (2009) Seismic design, assessment and retrofitting of concrete, Buildings edn. Springer, LondonGentry TR, Wight JK (1992) Reinforced concrete wide beam-column connections under earthquake-type loading. Report no. UMCEE 92-12. Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USAGómez-MartÃnez F (2015) FAST simplified vulnerability approach for seismic assessment of infilled RC MRF buildings and its application to the 2011 Lorca (Spain) earthquake. Ph.D. Thesis, Polytechnic University of Valencia, SpainGómez-MartÃnez F, Pérez GarcÃa A, De Luca F, Verderame GM (2015a) Comportamiento de los edificios de HA con tabiquerÃa durante el sismo de Lorca de 2011: aplicación del método FAST. Informes de la Construcción 67(537):e065 (in Spanish)Gómez-MartÃnez F, Pérez-GarcÃa A, Alonso Durá A, MartÃnez Boquera A, Verderame GM (2015b) Eficacia de la norma NCSE-02 a la luz de los daños e intervenciones tras el sismo de Lorca de 2011. In: Proceedings of Congreso Internacional sobre Intervención en Obras Arquitectónicas tras Sismo: L’Aquila (2009), Lorca (2011) y Emilia Romagna (2012), May 13–14, Murcia, Spain (in Spanish)Gómez-MartÃnez F, Verderame GM, De Luca F, Pérez-GarcÃa A, Alonso-Durá, A (2015c). High ductility seismic performances of wide-beam RC frames. In; XVI Convegno ANIDIS. September 13–17, L'Aquila, ItalyHawkins NM, Mitchell D (1979) Progressive collapse of flat plate structures. ACI J 76(7):775–808Iervolino I, Manfredi G, Polese M, Verderame GM, Fabbrocino G (2007) Seismic risk of RC building classes. Eng Struct 29(5):813–820Inel M, Ozmen HB, Akyol E (2013) Observations on the building damages after 19 May 2011 Simav (Turkey) earthquake. Bull Earthq Eng 11(1):255–283Kurose Y, Guimaraes GN, Zuhua L, Kreger ME, Jirsa JO (1991) Evaluation of slab-beam-column connections subjected to bidirectional loading. ACI Spec Publ 123:39–67LaFave JM, Wight JK (1997) Behavior of reinforced exterior wide beam-column-slab connections subjected to lateral earthquake loading. Report no. UMCEE 97-01. Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USALaFave JM, Wight JK (1999) Reinforced concrete exterior wide beam-column-slab connections subjected to lateral earthquake loading. ACI Struct J 96(4):577–586LaFave JM, Wight JK (2001) Reinforced concrete wide-beam construction vs. conventional construction: resistance to lateral earthquake loads. Earthq Spectra 17(3):479–505Li B, Kulkarni SA (2010) Seismic behavior of reinforced concrete exterior wide beam-column joints. J Struct Eng (ASCE) 136(1):26–36López-Almansa F, DomÃnguez D, Benavent-Climent A (2013) Vulnerability analysis of RC buildings with wide beams located in moderate seismicity regions. Eng Struct 46:687–702Masi A, Santarsiero G, Nigro D (2013a) Cyclic tests on external RC beam-column joints: role of seismic design level and axial load value on the ultimate capacity. J Earthquake Eng 17(1):110–136Masi A, Santarsiero G, Mossucca A, Nigro D (2013b) Seismic behaviour of RC beam-column subassemblages with flat beam. In: Proceedings of XV Convegno della Associazione Nazionale Italiana di Ingegneria Sismica, ANIDIS. Padova, ItalyMazzolani FM, Piluso V (1997) Plastic design of seismic resistant steel frames. Earthquake Eng Struct Dynam 26:167–191MEPP (2000a) Greek earthquake resistant design code, EAK 2000. Ministry of Environment, Planning and Public Works, AthensMEPP (2000b) Greek code for the design and construction of concrete works, EKOS 2000. Ministry of Environment, Planning and Public Works, Athens (in Greek)Miranda E, Bertero VV (1994) Evaluation of strength reduction factors for earthquake-resistant design. Earthq Spectra 10(2):357–379MPWS (2007) Specifications for buildings to be built in seismic areas. Turkish Standards Institution, Ministry of Public Works and Settlement, Ankara (in Turkish)Mwafy AM, Elnashai AS (2002) Calibration of force reduction factors of RC buildings. J Earthquake Eng 6(2):239–273NZS (2004) Structural design actions. Part 5: earthquake actions, NZS 1170.5. New Zealand Standards, WellingtonNZS (2006) Concrete structures standard: part 1—the design of concrete structures, NZS 3101 part 1. New Zealand Standards, WellingtonPan A, Moehle JP (1989) Lateral displacement ductility of reinforced concrete flat plates. ACI Struct J 86(3):250–258Panagiotakos TB, Fardis MN (2001) Deformations of reinforced concrete members at yielding and ultimate. ACI Struct J 98(2):135–148 [and Appendix 1 (69 pp)]Paulay T, Priestley MJN (1992) Seismic design of concrete and masonry structures. Wiley, New York, USAQuintero-Febres CG, Wight JK (1997) Investigation on the seismic behavior of RC interior wide beam-column connections. Report no. UMCEE 97-15. Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USAQuintero-Febres CG, Wight JK (2001) Experimental study of Reinforced concrete interior wide beam-column connections subjected to lateral loading. ACI Struct J 98(4):572–582Serna-Ros P, Fernández-Prada MA, Miguel-Sosa P, Debb OAR (2001) Influence of stirrup distribution and support width on the shear strength of reinforced concrete wide beams. Mag Concr Res 54(00):1–11Shuraim AB (2012) Transverse stirrup configurations in RC wide shallow beams supported on narrow columns. J Struct Eng 138(3):416–424Siah WL, Stehle JS, Mendis P, Goldsworthy H (2003) Interior wide beam connections subjected to lateral earthquake loading. Eng Struct 25:281–291Tore E, Demiral T (2014) A parametric study of code-based performance limits for wide beams. e-GFOS 5(8):1–11Vamvatsikos D, Cornell CA (2002) Incremental Dynamic Analysis. Earthquake Eng Struct Dynam 31:491–514Vidic T, Fajfar P, Fischinger M (1994) Consistent inelastic design spectra: strength and displacement. Earthquake Eng Struct Dynam 23:507–521Vielma JC, Barbat AH, Oller S (2010) Seismic safety of low ductility structures used in Spain. Bull Earthq Eng 8:135–15
APPLICATION OF THE CHARACTERISTIC ROOT INDEX MODEL TO THE ESTIMATION OF N-OCTANOL WATER PARTITION-COEFFICIENTS - POLYCHLORINATED-BIPHENYLS
The ability of the Characteristic Root Index (CRI) to predict the n-octanol/water partition coefficients (K-ow) of polychlorinated biphenyls (PCBs) has been demonstrated. The CRI for 58 congeners were calculated from the roots of the characteristic polynomial obtained from a square matrix comprising all possible orders of valence connectivity index - except zero order - for a congener as the entry. The correlation proposed for the estimation of K-ow of PCBs based on the CRI model contains only one variable and predicts log K-ow with high regression coefficient (r=0.998) and may be regarded satisfactory for environmental applications
VIBRATIONAL SPECTRUM OF ACETYLENE FROM 640 TO 870 nm
Author Institution:Vibration-rotation bands of acetylene in the region between 640 and 870 nm have been reinvestigated at high resolution using pressures up to 500 torr and path lengths up to 48 m. Improved values of band origins and excited state rotational constants have been obtained for several previously reported bands, and numerous ‘hot’ bands and perturbations to the ‘cold’ bands have been resolved
SOIL IMPROVEMENT TO COUNTER LIQUEFACTION USING COLLOIDAL SILICA GROUT
Soil liquefaction due to earthquakes is a major reason of damage to buildings and other structures. This study deals with soil improvement against liquefaction by injection of a particular stabiliser, colloidal silica, which is nontoxic and stable. Laboratory experiments were performed to determine the effects of colloidal silica grout injection regarding soil strength and deformations. The experiments involved static and dynamic triaxial tests on untreated and treated soil samples. The variables used in the tests are the relative density (loose - 40%, medium - 60% and dense - 80%), the confining pressure (100 and 300 kPa), and the curing period of silica treated samples (7 and 28 days). The results clearly indicate the significant increase in strength of the soil with colloidal silica injection. Furthermore, the relative increase is the highest in the sand of the lowest relative density which is the most probable candidate for soil improvement. The observations that the increase in the strength of colloidal silica treated sands with curing time is gradual and continuous add to the advantage of this method for use in soil improvement works. By using the dynamic test results, the equivalent Young modulus (or shear modulus) and the hysteretic damping ratio of untreated and treated soils are compared.C1 [Manav, Y.; Karakaplan, E.; Inel, M.] Pamukkale Univ, Dept Civil Engn, Kinikli Campus, Denizli, Turkey.[Toprak, S.] Gebze Tech Univ, Civil Engn Dept, TR-41400 Gebze, Kocaeli, Turkey
Denizli, Turkey
This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli, a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226 parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more stories, (2) pre-1975 constructed buildings, and (3) buildings with 3-5 stories. The future studies for evaluating and reducing seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled in a Geographical Information System (GIS) database
SOIL IMPROVEMENT TO COUNTER LIQUEFACTION USING COLLOIDAL SILICA GROUT
Soil liquefaction due to earthquakes is a major reason of damage to buildings and other structures. This study deals with soil improvement against liquefaction by injection of a particular stabiliser, colloidal silica, which is nontoxic and stable. Laboratory experiments were performed to determine the effects of colloidal silica grout injection regarding soil strength and deformations. The experiments involved static and dynamic triaxial tests on untreated and treated soil samples. The variables used in the tests are the relative density (loose - 40%, medium - 60% and dense - 80%), the confining pressure (100 and 300 kPa), and the curing period of silica treated samples (7 and 28 days). The results clearly indicate the significant increase in strength of the soil with colloidal silica injection. Furthermore, the relative increase is the highest in the sand of the lowest relative density which is the most probable candidate for soil improvement. The observations that the increase in the strength of colloidal silica treated sands with curing time is gradual and continuous add to the advantage of this method for use in soil improvement works. By using the dynamic test results, the equivalent Young modulus (or shear modulus) and the hysteretic damping ratio of untreated and treated soils are compared.C1 [Manav, Y.; Karakaplan, E.; Inel, M.] Pamukkale Univ, Dept Civil Engn, Kinikli Campus, Denizli, Turkey.[Toprak, S.] Gebze Tech Univ, Civil Engn Dept, TR-41400 Gebze, Kocaeli, Turkey
DO COMORBIDITIES IMPACT PERSISTENCE OF FIRST TUMOR NECROSIS FACTOR INHIBITOR TREATMENT IN RHEUMATOID ARTHRITIS? DATA FROM TURKBIO
Annual European Congress of Rheumatology (EULAR) -- JUN 03, 2020 -- ELECTR NETWORKAkkoc, Nurullah/0000-0002-3718-171XWOS: 000555905003171[No abstract available