Effects of soil structure interaction on behavior of reinforced concrete structures

Transcription

1 Journal of Structural Engineering & Applied Mechanic 18 Volume 1 Iue 1 Page RESEARCH ARTICLE Effect of oil tructure interaction on behavior of reinforced concrete tructure S. Kilicer 1, K. Ozgan * and A. Daloglu 1 Artvin Çoruh Univerity, Faculty of Engineering, Artvin, Turkey Karadeniz Technical Univerity, Department of Civil Engineering, Trabzon, Turkey Abtract The effect of the uboil have a very important role on the behavior of the tructure. For many year, thee effect have been neglected and the upertructure i deigned without conidering the oil-tructure interaction. However, earthquake in recent year have clearly hown the importance of oil-tructure interaction on the deign of the tructure, and tudie on oil-tructure interaction have increaed epecially in the lat 5 year. In thi tudy, the effect of oil-tructure interaction on behavior of reinforced concrete tructure i invetigated. The effect of uboil ha been taken into account uing Winkler and Vlaov Model in addition to rigid bae aumption. For thi purpoe, an interface that allow SAP and MATLAB to be ued imultaneouly ha been developed in MATLAB. It i oberved that oil-tructure interaction ha a ignificant effect on the column longitudinal reinforcement ratio of reinforced concrete tructure. Keyword OAPI; Reinforced concrete tructure; SAP; Soil-tructure interaction; Vlaov model Received: March 18; Accepted: 9 March 18 ISSN: (online) 18 Golden Light Publihing All right reerved. 1. Introduction The behavior of a tructure i affected by interaction between the upertructure, the foundation ytem and the uboil. Soil-tructure interaction analye the relation of thee ytem with each other. Soil behavior i the mot complicated ubject in thee relation. The reliability of tructural deign depend on how the oil tructure interaction i modelled accurately and realitically. The column at the bae are uually conidered a fixed in the deign neglecting the oil effect. Soil effect are only conidered in the deign of foundation. The oil-tructure interaction can be incorporated uing Winkler model which oil tructure i repreented by infinitely cloe pring. However, in the Winkler model, being the implet of the foundation model, the interaction between the pring are ignored and therefore the hear deformation of the uboil i neglected. But the main diadvantage of thee model i the neceity of determining the oil parameter. Modified Vlaov model facilitate the calculation of oil parameter depending on propertie oil and the tructure and type and the ditribution of load. There are many tudie available on plate or beam reting on elatic foundation in literature [1-7]. Beide thi, tudie have been alo carried out to invetigate the effect of the uboil on building behavior [8-17]. In thi tudy, behavior of reinforced concrete tructure i invetigated by conidering oiltructure interaction. In thi way, an interface * Correponding author kozgan@yahoo.com

2 9 Kilicer et al. developed in MATLAB i ued imultaneouly with SAP v.15 package program. A 1-torey building i analyzed and reult are compared for three different cae of upport condition. The oil parameter, natural vibration period, column axial force, column bending moment and longitudinal reinforcement ratio of the column for variou uboil aumption are preented cooperatively in figure and table.. Modified Vlaov model In the Modified Vlaov Model, uboil reaction of a tructure on elatic foundation i given by qz kw t w (1) in which w i the vertical urface diplacement of uboil, k i ubgrade reaction modulu and t i the oil hear parameter a defined below H E(1 ) ( z) k dz (1 )(1 ) z H t G z dz ( ) () where E, and G are elaticity modulu, Poion ratio and hear modulu of uboil repectively. ( z) i the mode hape function decribing the variation of vertical diplacement within the uboil, and it can be expreed a 1 z ( z) inh 1 inh H (3) where H i uboil depth to rigid bae, and i the third oil parameter and it can be evaluated a (1 ) H (1 ) w dxdy w dxdy (4) In Eq. (1-4), it i een that the modulu of ubgrade reaction, k, and the oil hear parameter, t, mode hape function ( z) the third parameter of the oil,, the depth of the uboil, H,, and vertical urface diplacement of the uboil are dependent variable. Therefore, the olution of thi complex oil-tructure interaction problem can be performed uing an iterative technique [4]. The third oil parameter,, i et to be equal to 1 to tart iteration. The iteration i repeated until the latet and previou value of within a precribed tolerance. 3. Methodology Verion of SAP after V1 have OAPI (Open Application Programming Interface) feature to enable two-way data exchange. By uing the OAPI function, a MATLAB interface ha been coded for calculating oil parameter iteratively. The model file created in SAP program i opened uing MATLAB interface and tarting value of oil parameter are aigned the model. After running of the SAP model, new oil parameter are calculated uing MATLAB code with the oil urface diplacement obtained from SAP. Thi iterative proce i repeated until the difference between oil urface parameter computed in two ucceive iteration converge to a predetermined value [5]. The flowchart for the analyi of reinforced concrete tructure reting on elatic foundation uing Vlaov model i given in Fig. 1.

3 Effect of oil tructure interaction on behavior of reinforced concrete tructure 3 Fig. 1. Flowchart for the analyi of reinforced concrete tructure on Vlaov model 4. Numerical example 4.1. Data for tructural ytem A 1-torey building with the formwork plan hown in Fig. ha been elected for the analye. The tory height i 3m. Young modulu, Poion ratio and denity of concrete are aumed a 8GPa,. and 5kN/m 3 repectively. Croectional dimenion of tructural element are 5 5cm for column, 3 6cm for beam and 3 cm for hear wall. The upertructure i reting on a mat foundation with dimenion of 18m m and thickne of 75cm. Thickne of ga concrete wall on beam are cm for outer wall and 1cm for interior wall. Denity of ga concrete wall ha been taken a 5kN/m 3. Slab with thickne of 15cm are ubjected to uniform load of kn/m. The modulu of elaticity of uboil i 947kN/m and Poion ratio for uboil i.5. Modulu of ubgrade reaction i taken a

4 31 Kilicer et al. 865kN/m 3 for Winkler foundation uboil model. The uboil end with a rigid rock layer after 8m. Equivalent Earthquake Load Method i ued for earthquake analyi according to Turkih Earthquake Regulation [18]. ±.5 eccentricity and 1.4G + 1.6Q, G + Q ± E x and G + Q ± E y load combination are conidered for the analyi. 4.. Reult Natural vibration period and bae hear force for variou foundation model are given in Table 1. A een from the table, firt natural vibration period increae when the oil effect i included in the behavior, and the highet value i obtained in the cae of Vlaov model. The effect of oil-tructure interaction caue natural vibration period to increae. Bae hear force calculated according to equivalent earthquake force method decreae in Vlaov model becaue the firt natural vibration period increae. Axial force and bending moment of column for variou uboil aumption are preented in Fig Bending moment of column are more affected compare to axial force. Axial force obtained by conidering oil-tructure interaction are greater for ome column and maller for ome column than that of rigid bae model. But it i certain that the uboil effect i changing the axial force ignificantly. A expected, the greater value of bending moment are obtained in Winkler and Vlaov model. Change in column bending moment caue longitudinal reinforcement ratio to increae. Longitudinal reinforcement ratio of column for variou uboil aumption are preented in Fig. 5. Longitudinal reinforcement ratio of column i calculated reducing two-dimenional combined bending to one dimenional combined bending in internal force given by Fig Longitudinal reinforcement ratio of column obtained by conidering oil-tructure interaction are greater than that of rigid bae model. The column longitudinal reinforcement ratio in the rigid oil tructure model i obtained at the minimum reinforcement ratio. In Winkler and Vlaov model, the column longitudinal reinforcement ratio are cloe to each other. Effect of uboil on longitudinal reinforcement ratio of column are clearly viible from the figure. Table 1. Natural vibration period and bae-hear force of tructure Soil-Structure Model T1x (n) T1y (n) Vtx (kn) Vty (kn) Rigid bae Winkler Model ,1 Modified Vlaov Model Fig.. Typical floor plan of the building

5 Reinforcement ratio () M (knm) N (kn) Effect of oil tructure interaction on behavior of reinforced concrete tructure Number of the column Rigid oil-tructure model Winkler Model Vlaov model Fig. 3. The column axial load 6 4 Number of the column Rigid oil-tructure model Winkler Model Vlaov model Fig. 4. The column bending moment,3,,1, Number of the column Rigid oil-tructure model Winkler Model Vlaov model Fig. 5. Longitudinal reinforcement ratio of column

6 33 Kilicer et al. 5. Concluion In thi tudy, uboil effect on the behavior of reinforced concrete tructure are invetigated. For thi purpoe, a 1-torey building i analyzed uing rigid bae aumption, Winkler and Vlaov uboil model. A computing tool developed in MATLAB i preented in the tudy for the analyi of building-uboil ytem. The reult how that ignificant change occur in internal force and longitudinal reinforcement ratio of column when uboil effect are taken into conideration on analyi of building. Reference [1] Buczkowki R, Torbacki W (1) Finite element modelling of thick plate on two-parameter elatic foundation. International Journal for Numerical and Analytical Method in Geomechanic 5: [] Çelik M, Saygun, A (1999) A method for the analyi of plate on a two-parameter foundation, International Journal of Solid and Structure 36: [3] Vallabhan CVG, Da YCP (1988) Parametric tudy of beam on elatic foundation, International Journal of Engineering Mechanic 114 (1):7-8. [4] Vallabhan CVG, Da YC (1991) A refined model for beam on elatic foundation, International Journal of Solid and Structure, 7, (5): [5] Kılıçer S, Özgan K, Daloğlu AT. Analyi of mat foundation uing Vlaov model, nd Soil Mechanic and Foundation Engineering Sympoium: Soil-Structure Interaction in Theory and Practie, April 14, Antalya, Turkey (in Turkih). [6] Sapuontzaki EJ, Katikadeli JT () A new model for lab and beam tructure-comparion with other model. Computer and Structure 8: [7] Wen PH, Aliabadi MH (9) Boundary element formulation for Mindlin plate on an elatic foundation with dynamic load. Engineering Analyi with Boundary Element 33: [8] Karabörk T (9) Nonlinear 3D Dynamic Analyi of Reinforced Concrete Structure by Mean of Soil-Structure Interaction, Electronic Journal of Contruction Technologie 5 (1):5-36 (in Turkih). [9] Thangaraj DD, Ilamparuthi K (1) Interaction analyi of mat foundation and pace frame for non-linear behaviour of the oil. Bonfring International Journal of Indutrial Engineering and Management Science (4):33-4. [1] Derdiman, MK (13) Effect of Soil with Different Propertie on Natural Period of Structure at RC High Rie Building, Afyon Kocatepe Univerity Journal of Science and Engineering 13:9-15 (In Turkih). [11] Frydryek K, Janco R, Gondek H (13) Solution of beam, frame and 3D tructure on elatic foundation uing FEM. International Journal of Mechanic 4 (7): [1] Hamarat MA, Çalık Karaköe ÜH, Orakdöğen E. Seimic analyi of tructure reting on two parameter elatic foundation, 15 WCEE, 1, Liboa [13] Ionecu A, Calbureanu M, Negru M. Bouineq method in eim analyi of a building tructure uing ANSYS program, WSEAS International Conference, Vouliagmeni, April 13, Athen, Greece, [14] Ahmed M, Mohamed MH, Mallick J, Haan MA (14) 3D-analyi of oil-foundation-tructure interaction in layered oil. Open Journal of Civil Engineering 4: [15] Korkmaz KA, Demir F (1) Soil tructure interaction effect on tructural earthquake behaviour, The Journal of Graduate School of Natural and Applied Science of Mehmet Akif Eroy Univerity 3(1):1-17 (In Turkih). [16] Avcıoğlu O, Orakdöğen E (15) Time hitory analyi of tructure on Vlaov type elatic ubgrade, Pamukkale Univerity Journal of Engineering Science 1(3):13-18 (In Turkih). [17] Kahraman S, Mıır İS, Özden G. The effect of uing contant and variable ubgrade modulu on the tructural behaviour, Sixth National Conference on Earthquake Engineering, October 7, İtanbul, Turkey, 17-8 (In Turkih). [18] TDY-7: Specification for the building to be contructed in diater area, Minitry of Public Work and Settlement, Ankara, Turkey, 7 (In Turkih).