Assessment of near-field and far-field strong ground motion effects on soil-structure SDOF system 2 2 The distinctive characteristics of near-field earthquake records can lead to different structural responses from those experienced in far-field ones. Furthermore, soil-structure interaction (SSI) can have a crucial influence on the seismic response of structures founded on soft soils however, in most of the time has been neglected nonchalantly. This paper addresses the effects of near-field versus far-field earthquakes on the seismic response of single degree of freedom (SDOF) system with considering SSI. A total 71 records were selected in which near-field ground motions have been classified into two categories: first, records with a strong velocity pulse, (i.e. forward-directivity) second, records with a residual ground displacement (i.e. fling-step). Findings from the study reveal that pulse-type near-field records generally produce greater seismic responses than far-field motions especially at high structure-to-soil stiffness ratios. Moreover, the importance of considering SSI effects in design of structures is investigated through an example. Finally, parametric study between Peak Ground Velocity to Peak Ground Acceleration ratio (PGV/PGA) of pulse-like ground motions and maximum relative displacement indicate that with increase in structure-to-soil stiffness ratios, earthquakes with higher PGV/PGA ratio produce greater responses. 153 166 2014/07/23 1393/5/1 2015/09/26 1394/7/4 M. Davoodi M. Davoodi International Institute of Earthquake Engineering and Seismology Iran m-davood@iiees.ac.ir M. Sadjadi M. Sadjadi International Institute of Earthquake Engineering and Seismology Iran mani.sajadi@yahoo.com Soil-structure interaction SDOF system Near-field earthquake Far-field earthquake PGV/PGA [1] Stewart JP, Chiou S, Bray J, Graves R, Somerville P, Abrahamson N. Ground motion evaluation procedures for performance-based design, Pacific Earthquake Engineering Research Center (PEER), Report No. 09, 2001.##[2] Corigliano M. Seismic Response of Deep Tunnels in Near-Fault Conditions, Ph.D. Thesis, Italy, Politecnico di Torino, 2007.##[3] Somerville P, Smith N, Graves R, Abrahamson N. Modification of empirical strong ground motion attenuation relations to include the amplitude and duration effects of rupture directivity, Seismological Society Letters, 1997, No. 1, Vol. 68, pp. 180-203. ##[4] Bolt BA. Earthquakes, New York, W.H, Freeman, 1993.##[5] Bertero V, Mahin SA, Herrera RA. A seismic design implications of near-fault San Fernando earthquake records, Earthquake Engineering & Structural Dynamics Journal, 1978, No. 1, Vol. 6, pp. 31-42.##[6] Mahin SA, Bertero V. An evaluation of inelastic seismic design spectra, ASCE Journal of Structural Engineering, 1981, Vol. 107, pp. 1777-95.##[7] Hall JF, Heaton TH, Halling MW, Wald DJ. Near source ground motion and its effects on flexible buildings, Earthquake Spectra, 1995, No. 4, Vol. 11, pp. 569-605.##[8] Iwan WD. Drift spectrum: measure of demand for earthquake ground motions, Journal of Structural Engineering, 1997, No. 4, Vol. 123, pp. 397-404.##[9] Chopra A, Chintanapakdee C. Comparing response of SDF systems to near-fault and far-fault earthquake motions in the context of spectral regions, Earthquake Engineering and Structural Dynamics, 2001, No. 12, Vol. 30, pp. 1769-89.##[10] Alavi B, Krawinkler H. Behavior of moment-resisting frame structures subjected to near-fault ground motions, Earthquake Engineering and Structural Dynamics, 2004, Vol. 33, pp. 687-706 (DOI: 10.1002/eqe.369).##[11] Kalkan E, Kunnath SK. Effects of fling step and forward directivity on seismic response of buildings, Earthquake Spectra, 2006, No. 2, Vol. 22, pp. 367-390.##[12] Ghahari F, Jahankhah H, Ghannad MA. Study on elastic response of structures to near-fault ground motions through record decomposition, Soil Dynamics and Earthquake Engineering, 2010, Vol. 30, pp. 536-546.##[13] Mazza F, Mazza M. Nonlinear modeling and analysis of r.c. framed buildings located in a near-fault area, The Open Construction & Building Technology Journal, 2012, Vol. 6, pp. 346-354, ISSN: 1874-8368.##[14] Wolf JP. Dynamic soil-structure interaction, Prentice-Hall, INC, Englewood cliffs, New Jersey 07632, 1985.##[15] Kramer SL. Geotechnical Earthquake Engineering, Prentice-Hall, Upper Saddle River, New Jersey 07458, 1996.##[16] Ghannad MA. A study on the effect of soil-structure interaction on the dynamic properties of structures using simplified methods, Ph.D. thesis, Japan, 1998, Nagoya University.##[17] Gazetas G. Seismic design of foundation and soil-structure interaction, First European Conference on Earthquake Engineering and Seismology, Geneva, Switzerland, 3-8 September 2006.##[18] Ricardo D. Ambrosini, Jorge D. Riera, Rodolfo F. Danesi, on the influence of foundation flexibility on the seismic response of structures, Computers and Geotechnics, 2000, Vol. 27, pp. 179-197.##[19] Ghannad MA. Effects of soil-structure interaction on response of structures subjected to near-fault earthquake records, Seismic Engineering Conference Commemorating the 1908 Messina and Reggio Calabria earthquake, Italy, 2008.##[20] Zhang J, Tang Y. Dimensional analysis of linear soil-foundation-structure system subjected to near-fault ground motions, Structure Congress\'08, Vancouver, Canada, April 2008.##[21] Azarhoosh Z, Ghodrati Amiri GR. Elastic response of soil-structure systems subjected to near-fault rupture directivity pulses, Soil Dynamics and Earthquake Engineering, Proceedings of the Geo shanghai International Conference, June 3-5, 2010, Shanghai, China - Hind: 90, 50 EUR.##[22] Minasidis G, Hatzigeorgiou GD, Beskos DE. SSI in steel frames subjected to near-fault earthquakes, Soil Dynamics & Earthquake Engineering, 2014, Vol. 66, pp. 56-68.##[23] Gelagoti F, Kourkoulis R, Anastasopoulos I, Gazetas G. Rocking-isolated frame structures: Margins of safety against toppling collapse and simplified design approach, Soil Dynamics and Earthquake Engineering, 2012, Vol. 32, pp. 87-102.##[24] Davoodi M, Sadjadi M, Goljahani P, Kamalian M. Effects of near-field and far-field earthquakes on seismic response of sdof system considering soil structure interaction, 15th World Conference on Earthquake Engineering. Lisbon, Portugal, 2012. ##[25] Sadjadi M. Effects of soil structure interaction on response of structure subjected to near-field earthquakes with fling-step characteristic, M.Sc. thesis, Iran, 2012, SRBIAU.##[26] Shuang LI, Li-li XIE. Progress and trend on near-field problems in civil engineering, Acta Seismological Sinica, 2007, No. 1, Vol. 20, pp. 105-114.##[27] Bray JD, Rodrigues-Marek A. Characterization of forward-directivity ground motions in the near-fault region, Soil Dynamics and Earthquake Engineering, 2004, No. 11, Vol. 24, pp. 815-828.##[28] Bozorgnia B, Bertero V. Earthquake Engineering: from Engineering Seismology to Performance-Based Engineering, Florida, CRCPress, 2004.##[29] Alavi B, Krawinkler H. Effects of near-fault ground motions on frame structures, blume, John A. Blume, Earthquake Engineering Center Stanford, California, 2001, No. 138. ##[30] Rodriguez-Marek A, Bray JD. Seismic site response for near-fault forward- directivity ground motion, Journal of Geotechnical and Geoenvironmental Engineering ASCE, December 2006, pp. 1611-1620.##[31] PEER. Next Generation Attenuation Database, Pacific Earthquake Engineering Research Center, http://peer.berkeley.edu/nga/index.html, 2006.##[32] Chopra, A. Dynamics of Structures, Prentice-Hall of India, New Delhi, 2002.##[33] International Code Council (ICC), International Building Code. Falls Church (VA), 2000.##[34] The US. NRC Regulatory Guide 1.6 spectrum, Design Response Spectra For Seismic Design Of Nuclear Power Plants, 1973.##[35] Bertero V. Establishment of design earthquakes-Evaluation of present methods, Proceedings of the International Sympusiom on Earthquake Structural Engineering, St. Louis, 1976, Vol. 1, pp. 551-580.##[36] Sucuogly H, Erberik MA, Yucemen MS. Influence of peak ground velocity on seismic failure probability, Proceedings of the 4th International Conference of the European Association for Structural Dynamics, (EURODYN’ 99), Prague, Czech Republic, 1999.##[37] Makris N, Black JC. Evaluation of peak ground velocity as a ‘‘good’’ intensity measure for near-source ground motions, Journal of Engineering Mechanics, No. 9, Vol. 130, September 2004, pp. 1032-1044.##[38] McGuire RK. Seismic ground motion parameter relations, Journal of the Geotechnical Engineering Division, ASCE, 1978, Vol. 104, pp. 481-490.##[39] Kermani E, Jafarian Y, Baziar MH. New predictive models for the v max/a max ratio of strong ground motions using genetic programming, IJCE, 2009, Vol. 7, No. 4, pp. 236-247.##[40] Consenza E, Manfredi G. Damage indices and damage measures, Progress in Structural Engineering and Materials, 2000, Vol. 2, pp. 50-59.##[41] Zhu TJ, Tso WK, Heidebrecht AC. Effect of peak ground a/v ratio on structural damage, Journal of Structural Engineering, 1988, Vol. 114, pp. 1019-1037.##[42] Meskouris K, Kratzig WB, Hanskotter U. Seismic motion damage potential for R/C wall-stiffened buildings In: Fajfar P, Krawinkler H. (eds) Nonlinear seismic analysis and design of reinforced concrete buildings, Oxford, Elsevier Applied Science, 1992, pp. 125-136.## ##

Utilization of high liquid limit soil as subgrade materials with pack-and-cover method in road embankment construction 2 2 In order to improve the utilization of high liquid limit soil, the fundamental properties of high liquid limit soil and its direct utilization method are studied in this paper. This work involves both laboratory and fieldwork experiments. The results show that clay and sandy clay both with high liquid limit can be directly used for the road embankment, and the degree of compaction can be controlled at 88 %. The pack-and-cover method in accordance with Chinese technical specifications is recommended to be operated in the engineering practice. The packed height should be less than 8 meters and the total height of embankment no more than 12 meters in the interests of settlement. From the view of stability, the optimal thickness value of top sealing soil layer and edge sealing soil layer is about 1.5 meter respectively, and the geogrid reinforcement spacing should be about 2.0 meters. In addition, based on Yun-Luo expressway in China filled with high liquid limit soil, the construction techniques and key points of quality control in subgrade with pack-and-cover method are compared and discussed in detail, and the feasibility of these schemes are verified by the experimental results. 167 174 2014/07/232014/01/8 1392/10/18 2015/09/262015/09/26 1394/7/4 x. liu x. liu Hohai University China liuxin100@hhu.edu.cn K. Sheng K. Sheng Hohai University China J.H. Hua J.H. Hua Hohai University China B.N. Hong B.N. Hong Hohai University China J.J. Zhu J.J. Zhu Hohai University China High liquid limit soil Direct utilization Pack-and-cover method Experimental road Construction technology [1] CCCC First Highway Engineering Co. LTD. Technical Code for Construction of Highway Subgrades (JTG F10-2006). Beijing: People\'s Communications Publishing House, 2006.##[2] Jegede G. Effect of soil properties on pavement failures along the F209 highway at Ado-Ekiti, south-western Nigeria, Construction and Building Materials, 2000, No. 6/7, Vol. 14, pp. 311-315.##[3] Zeng Jing, Deng Zhi-bin, Lan Xia, Sheng Qian. Experimental study on properties of high liquid limit soil and red clay of Zhucheng Highway, Rock and Soil Mechanics, 2006, No. 1, Vol. 27, pp. 89-93.##[4] Gary Hicks R. Alaska soil stabilization design guide, Department of Transportation and Public Facilities Research & Technology Transfer, Alaska, 2002.##[5] Luo Zhi-qiang. Application of high liquid limit soil in freeway construction, Central South Highway Engineering, 2004, No. 1, Vol. 29, pp. 87-89.##[6] Zhang Guo-bing, YU Gai-ning. Study on improvement of high liquid limit soil, Journal of Highway and Transportation Research and Development, 2005, No. 11, Vol. 22, pp. 71-74.##[7] Abu-Zreig MM, Al-Akhras NM, Attom MF. Influence of heat treatment on the behavior of clayey soils. Applied Clay Science, 2001, No. 3, Vol. 20, pp. 129-135.##[8] Tan Ö, Yilmaz L, Zaimoğlu AS. Variation of some engineering properties of clays with heat treatment, Materials Letters, 2004, No. 7/8, Vol. 58, pp. 1176-1179.##[9] Deka S, Sreedeep S, Dash SK. Re-evaluation of laboratory cone penetration method for high liquid limit based on free swell property of soil, Geotechnical Testing Journal, 2009, No. 6, Vol. 32, pp. 553-558.##[10] Luo B, Xiong Z. Test study on improving high liquid limit red clay with crushed stone, Highway Engineering, 2009, No. 2, Vol. 30, pp. 131-134.##[11] Fang-hua, L. I. Experimental study of optimal proportion of gravel adopted to improve the properties of high liquid limit soil subgrade, Rock and Soil Mechanics, No. 3, 2010, Vol. 31, pp. 785-788. ##[12] Basha EA, Hashim R, Mahmud HB, Muntohar AS. Stabilization of residual soil with rice husk ash and cement, Construction and Building Materials, 2005, No. 6, Vol. 19, pp. 448-453.##[13] Degirmenci N, Okucu A, Turabi A. Application of phosphogypsumin soil stabilization, Building and Environment, No. 9, 2007, Vol. 42, pp. 3393-3398.##[14] Guney Y, Sari D, Cetin M, Tuncan M. Impact of cyclic wetting-drying on swelling behavior of lime-stabilized soil, Building and Environment, No. 2, 2007, Vol. 42, pp. 681-688.##[15] Sakr MA, Shahin MA, Metwally YM. Utilization of lime for stabilizing soft clay soil of high organic content, Geotechnical and Geological Engineering, No. 1, 2009, Vol. 27, pp. 105-113.##[16] Zhang Wen-hui, et al. Experimental study on the feasibility of using water glass and aluminum sulfate to treat complications in high liquid limit soil subgrade, Advances in Materials Science and Engineering, 2015, pp. 1-8.##[17] Zeng S. Study of lab improvement test for high liquid limit clay, China and Overseas Highways, 2007, Vol. 27, pp. 208-210.##[18] Test Methods of Soils for Highway Engineering (JTG E40-2007), China Communications Press, Beijing, China, 2007.##[19] Zhang Wen-hui, XI Wen-yong, Wang Bao-tian, Hong Bao-ning. Test study of high liquid limit clay modified by quick lime used as sub-grade material, Journal of Central South University of Technology, No. s2, 2008, Vol. 15, pp. 126-130. ##[20] CCCC Second Highway Consultants Co. LTD. Code for Design of Highway Subgrades(JTGD30-2004), Beijing: People\'s Communications Publishing House. 2004.##[21] The Ministry of Water Resources of The People\'s Republic of China. Standard for Test Methods of Earthworks (GB/T10123-1999), Beijing, China Water Power Press, 1999.##[22] Ministry of the People\'s Republic of China. Technical Standard of Highway Engineering (JTG B01-2003), Beijing, People\'s Communications Publishing House, 2004.##[23] CCCC First Highway Consultants Co. LTD. Technical Code for Design and Construction of Highway Embankment on Soft Ground (JTJ 017-96, Beijing, People\'s Communications Publishing House, 1996.##[24] She Xiao-nian, liu Yin-sheng. Study of pack-cover method of high liquid limit soil, Hunan Communication Science And Technology, 2003, No. 4, Vol. 29, pp. 28-30.##[25] Ignjatovic, Miroslav; Ignjatovic, Snezana. Determination of the final slope angle of the open pit mine during exploitation of oil shale from Aleksinac deposit by GeoStudio 2007-SLOPE/W program, Technics Technologies Education Management-Ttem, 2011, No. 3, Vol. 6, pp. 615-621.##[26] Guo Pingye, Li Wei-chao. Development and implementation of Duncan-Chang constitutive model in Geo Studio 2007, International Conference on Advances in Computational Modeling and Simulation (ACMS), 2012, No. 31, pp. 395-402.##[27] Rowe R. Kerry, Taechakumthorn C. Design of reinforced embankments on soft clay deposits considering the viscosity of both foundation and reinforcement, Geotextiles and Geomembranes, 2011, No. 5, Vol. 29, pp. 448-461.##[28] Liu Chun-yuan, Dou Yuan-min. Experiment research on filling super highway bed with high liquid clay, Journal of Hebei University of Technology, 1999, No. 4, Vol. 28, pp. 64-68.##[29] Huang Hou-qing. The application study of high liquid limit soil in the embankment engineering, Central South Highway Engineering, 2001, No. 4, Vol. 26, pp. 01-03.## ##

Effects of mean net stress and cyclic deviatoric stress on the cyclic behavior of normally consolidated unsaturated kaolin 2 2 Experimental study of the cyclic behavior of unsaturated materials is more complex than that of the saturated materials due to the required equipment, experience and time. Furthering investigations in the field of unsaturated materials is necessary to better understand its complexity and sensitivity of unsaturated cyclic parameters to different determinants such as suction path, stress path, loading speed, deviatoric stress amplitude, physical specifications, and etc. To this end, the main focus of this study has been to analyze the effects of factors such as mean net stress and deviatoric stress levels in fast cyclic loading on the cyclic behavior of a normally consolidated unsaturated fine-grained trade soil, namely the Zenoz kaolin. Various unsaturated tests were performed in three mean net stress levels and three amplitudes of cyclic deviatoric stress levels. Results showed that increase of suction in the same strain level leads to increase in stiffness in normally consolidated samples (i.e. increase in elastic modulus and shear modulus and decrease in damping ratio). Also, in the same suction value and strain level, increase of the mean net stress during the isotropic consolidation causes to the denser normally consolidated samples and results to increase of elastic modulus and shear modulus, and decrease of damping ratio. 175 184 2014/07/232014/01/82015/06/8 1394/3/18 2015/09/262015/09/262015/09/20 1394/6/29 M. Mojezi M. Mojezi International Institute of Earthquake Engineering and Seismology Iran m.mojezi@iiees.ac.ir M.K. Jafari M.K. Jafari International Institute of Earthquake Engineering and Seismology Iran jafari@iiees.ac.ir M. Biglari M. Biglari Razi University Iran m.biglari@razi.ac.ir Cyclic loading Unsaturated Zenoz kaolin Mean net stress Deviatoric stress amplitude Suction controlled-cyclic triaxial [1] Marinho EAM, Chandler RJ, Crilly MS. Stiffness measurements on a high plasticity clay using bender elements, In Unsaturated Soils, Proceedings of the First International Conference on Unsaturated Soils, UNSAT 95, Paris, France, AA Balkema, Rotterdam, 1995, Vol. 1, pp. 535-539.##[2] Picornell M, Nazarian S. Effects of soil suction on low-strain shear modulus of soils, Proceedings of Second International Conference on Unsaturated Soils, August 27-30, Beijing, China, 1998, Vol. 1, pp. 102-107.##[3] Cabarkapa Z, Cuccovillo T, Gunn M. Some aspects of the pre-failure behavior of unsaturated soil, Proceedings of second international conference on prefailure behavior of geomaterials, Torino, 1999, pp. 159-165.##[4] Mancuso C, Vassallo R, d\'Onofrio A. Soil behaviour in suction controlled cyclic and dynamic torsional shear tests, Proceedings of the Asian Conference on Unsaturated Soils, Singapore, 2000, Vol. 1, pp. 539-544.##[5] Vassallo R, Mancuso C. Soil behaviour in the small and the large strain range under controlled suction conditions, International Workshop on Experimental Evidence and Theoretical Approaches in Unsaturated Soils, Torento, 2000, pp. 75-90.##[6] Vassallo R, Mancuso C, Vinale F. Effects of net stress and suction history on the small-strain stiffness of a compacted clayey silt, Canadian Geotechnical Journal, 2007, Vol. 44, pp. 447-462.##[7] Vassallo R, Mancuso C, Vinale F. Modelling the influence of stress–strain history on the initial shear stiffness of an unsaturated compacted silt, Canadian Geotechnical Journal, 2007, Vol. 44, pp. 463-472.##[8] Becker Th, Meissner H. Direct suction measurement in cyclic triaxial test Devices, Proceedings of 3rd International Conference on Unsaturated Soils, Recife, Brasil, 2002.##[9] Becker T, Li T. Behavior of unsaturated soils subjected to cyclic loading, Proceedings of International Workshop on Unsaturated Soiols, Weimar, Germany, Springer, 2003, pp. 347-364.##[10] Mendoza CE, Colmenares JE, Merchan VE. Stiffness of an unsaturated compacted clayey soil at very small strains, Proceedings of an International Symposium On Advanced Experimental Unsaturated Soil Mechanics, Trento, Italy, 2005, pp.199-204.##[11] Cabarkapa Z, Cuccovillo T. Automated Triaxial Apparatus for Testing Unsaturated Soils, Geotechnical Testing Journal, 2006, No. 1, Vol. 29.##[12] Ng CWW, Yung SY. Determination of the anisotropic shear stiffness of an unsaturated decomposed soil, Géotechnique, 2008, No. 1, 58, pp. 23-35.##[13] Pineda JA, Lima A, Romero EE. Influence of hydraulic path on the low-strain shear modulus of a stiff clay, Unsaturated Soils: Advances in Geo-Engineering, Taylor & Francis Group, London, 2008.##[14] d’Onza F, d’Onforio A, Mancuso C. Effects of unsaturated soil state on the local seismic response of soil deposits, Unsaturated Soils: Advances in Geo-Engineering, Taylor & Francis Group, London, 2008.##[15] Ng CWW, Xu J, Yung SY. Effects of wetting-drying and stress ratio on anisotropic stiffness of an unsaturated soil at very small strains, Canadian Geotechnical Journal, 2009, Vol. 46, pp. 1062-1076.##[16] Biglari M, Jafari MK, Shafiee A, Mancuso C, d\'Onofrio A. Dynamic properties of unsaturated kaolin measured in a wide strain range with new suction controlled cyclic triaxial device, Geotechnical Testing Journal, ASTM, AIP ID: 001105GTJ, 2011.##[17] Biglari M, d\'Onofrio A, Mancuso C, Jafari MK, Shafiee A, Ashayeri I. Small-strain stiffness of Zenoz kaolin in unsaturated condition, Canadian Geotechnical Journal, 2012, Vol. 49, pp. 1-12.##[18] Ng CWW, Xu J. Effects of current suction ratio and recent suction history on small-strain behaviour of an unsaturated soil, Canadian Geotechnical Journal, 2012, No. 2, Vol. 49, pp. 226-243.##[19] Heitor A, Indraratna B, Rujikiatkamjorn C. Laboratory study of small-strain behavior of a compacted silty sand, Canadian Geotechnical Journal, 2013, No. 2, Vol. 50, pp. 179-188.##[20] Suriol J, Romero E, Lloret A, Vaunat J. Small-strain shear stiffness of compacted clays: Initial state and microstructural features, Unsaturated Soils: Research & Applications, 2014, pp. 769-775.##[21] Walton-Macaulay C, Bryson LS, Hippley BT, Hardin BO. Uniqueness of a constitutive shear modulus surface for unsaturated soils, ASCE, International Journal of Geomechanics, 10.1061/(ASCE)GM.1943-5622.0000470, 06015002, 2015.##[22] Hilf JW. An Investigation of Pore Water Pressure in Compacted Cohesive Soils, Technical Memo, Bureau of 479 Reclamation, Denver, 1956.##[23] Ladd RS. Preparing testing specimens using under- compaction, Geotechnical Testing Journal, 1978, pp. 16-23.##[24] Sivakumar V. A Critical State Framework for Unsaturated Soils, Ph.D. thesis, University of Shefield, Shefield, U.K, 1993.## ##

Modeling of hydraulic fracture problem in partially saturated porous media using cohesive zone model 2 2 In this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. The model is derived from the framework of generalized Biot theory. The fracture propagation is governed by a cohesive fracture model. The flow within the fracture zone is modeled by the lubrication equation. The displacement of solid phase, and the pressure of wetting and non-wetting phases are considered as the main unknown parameters. Other variables are incorporated into the model using empirical relationships between saturation, permeability and capillary pressure. Zero-thickness element and conventional bulk element are used for propagating fracture and the surrounding media, respectively. The model is validated with respect to analytical solution of hydraulic fracture propagation problem in saturated media and then the problem is solved in semi-saturated media, considering the wetting and non-wetting pore fluid. 185 194 2014/07/232014/01/82015/06/82014/09/28 1393/7/6 2015/09/262015/09/262015/09/202015/11/3 1394/8/12 F. Dastjerdy F. Dastjerdy K.N.Toosi University of Technology Iran fdastjerdy@mail.kntu.ac.ir O.R. Barani O.R. Barani K.N.Toosi University of Technology Iran barani@kntu.ac.ir F. Kalantary F. Kalantary K.N.Toosi University of Technology Iran fz_kalantary@kntu.ac.ir Hydraulic fracture Partially saturated media Cohesive fracture Tow-phase fluid flow Modeling [1] Ghasemzadeh H. (2008) Heat and contaminant transport in unsaturated soil. International Journal of Civil Engineerng, 6(2):90-107.##[2] Luo Y. L. (2013) A continuum fluid-particle coupled piping model based on solute transport. International Journal of Civil Engineering, Transaction B: Geotechnical Engineering, 11(1): 38-44.##[3] Ashayeri I, Kamalian M, Jafari M.K, Biglari M., Mirmohammad Sadeghi M. (2014) Two-dimensional time domain fundamental solution to dynamic unsaturated poroelasticity. International Journal of Civil Engineering, Transaction B: Geotechnical Engineering, 12(2): 110-133.##[4] Attia H. A., El-Meged W. A., Abbas W., Abdeen M. A. M. (2014) Unsteady flow in a porous medium between parallel plates in the presence of uniform suction and injection with heat transfer. International Journal of Civil Engineering, Transaction A: Civil Engineering, 12(3): 277-281##[5] Simoni L, Secchi S (2003) Cohesive fracture mechanics for a multi-phaseporous medium. Eng Comput , 20:675-698.##[6] Schrefler BA, Secchi S, Simoni L (2006) On adaptive refinement techniques in multi-filed problems including cohesive fracture. Comput Methods Appl Mech Eng, 195:444-461.##[7] Secchi S, Simoni L, Scherfler BA. (2007). Mesh adaptation and transfer schemes for discrete fracture propagation in porous material. Int J Numer Anal Methods Geomech, 31:331-345.##[8] Segura JM, Carol I (2008) Coupled HM analysis using zero-thickness interface elements with double nodes. Part I:Theoretical model. Int J Numer Anal Meth Geomech, 32, 32:2083-2101.##[9] Rethore J, R. de Borst, Abellan MA (2008) A two-scale model for fluid flow in an unsaturated porous medium with cohesive cracks. Computational Mechanics. 42;227–238.##[10] Adachi J, Detournay E (2008) Plane strain propagation of a hydraulic fracture in a permeable rock, Eng. Frac Mech. 75;4666–4694.##[11] Chen Z, Bunger A, Zhang Z, Jeffrey R(2009) Cohesive zone finite element-based modeling of hydraulic fractures, Acta Mech Solida Sinica. 22 ;443–452.##[12] Lecampion B(2009) An extended finite element method for hydraulic fracture problems, Commun Numer Methods Engng. 25 ;121–33. ##[13] Kovalyshen Y(2010) Fluid-Driven Fracture in Poroelastic Medium. PhD thesis, university of minnesota ##[14] Sarris E, Papanastasiou P(2011) The influence of the cohesive process zone in hydraulic fracturing modelling, Int J Fract. 167(1) ; 33–45.##[15] Barani OR, Khoei AR (2011) Modeling of cohesive crack growth in partially saturated porous media; a study on the permeability of cohesive fracture. Int J Fract, 167:15–31.##[16] Khoei AR, Barani OR (2011) Modeling of dynamic cohesive fracture propagation in porous media. Int J Numer Anal Meth Geomech, 35:1160-1184. ##[17] Khoei AR, Haghighat E (2011) Extended finite element modeling of deformable porous media with arbitrary interfaces, Applied Mathematical Modelling. 35;5426–5441.##[18] Khoei AR, Mohamadnejad T(2012) An extended finite element method for fluid flow in partially saturated porous media with weak discontinuities;the convergence analysis of local enrichment strategies, Comput Mech. DOI 10.1007/s00466-012-0732-8.##[19] Carrier B, Granet S (2012) Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model, Eng. Frac Mech. 79; 312–328. ##[20] Chen Z (2012) Finite element modelling of viscosity-dominated hydraulic fractures, Journal of Petroleum Science and Engineering. 88-89;136–144.##[21] Sarris E, Papanastasiou P, (2013) Numerical modeling of fluid-driven fractures in cohesive poroelastoplastic continuum, Int J Numer Anal Meth Geomech.37;1822-1846.##[22] Ru Z, Zhao H, Wang M, (2003) Numerical Modeling of Hydraulic Fracture Propagation Using Extended Finite Element Method, Poromechanics. 1923-1929.##[23] Mohamadnejad T, Khoei AR (2012) Hydro-mechanical modeling of cohesive crack propagation in multiphase porous media using the extended finite element method. Int J Numer Anal Meth Geomech, DOI: 10.1002/nag.2079. ##[24] Lewis RW, Schrefler BA (1998) The finite element method in the staticand dynamic deformation and consolidation of porous media. New York, NY: John Wiley. ##[25] Espinosa HD, Zavattieri PD, (2003) A grain level model for the study of failure initiation and evolution in polycrystalline brittle materials. Part I: Theory and numerical implementation, Mech Mater. 35;333–364.##[26] Song SH, Paulino GH, Buttlar WG, (2006) A bilinear cohesive zone model tailored for fracture of asphalt concrete considering viscoelastic bulk materia. Eng Fract Mech, 73;2829-2848.## [27] Spence DA, Sharp P (1985) Self-similar solutions for elasto-hydrodynamic cavity flow. Proc royal Soc London A, A 400, 40:289-313. ##[28] Geertsma J, Klerk F (1969) A rapid method of predicting width and extent of hydraulically induced fractures. 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Liquefaction potential of reinforced silty sands 2 2 In this study a series of cyclic triaxial tests were performed to examine the undrained dynamic resistance of silty sand reinforced with various arrangements of geotextile layers. The silt content of samples varies in percentage from 0, 10, 20, 30, 40 and 50%. A total of 32 laboratory cyclic triaxial tests have been performed on silty sand samples reinforced with geotextile layers in different depths. All tests were performed with 100 kPa confining pressure, subjected to an isotropic consolidated undrained (CIU) condition. The tests were conducted at a frequency of 2 Hz. Results indicate that both the geotextile arrangement and the silt content were most essential in the liquefaction potential of reinforced sands. An increase in the number of geotextile layers enhanced the cyclic resistance of reinforced samples against the liquefaction potential. It was also found that when the geotextile layer was posited near the top of the specimen (load application part) the liquefaction resistance would increase (e.g. for clean sands, the improvement of liquefaction resistance caused by the geotextile layer had a 0.2 depth, and the sample height was 5.5 times greater than the geotextile layer inserted in mid height of sample H). Based on the obtained results, effects of geotextile on liquefaction resistance decreased as ﬁnes content increased to about 33%. Further increase in the ﬁnes content however, would lead to higher in reinforcement advantages. The liquefaction improvement is more effective with a higher number of geotextile layers. The results also revealed that the reinforcement effect in FC≈33 % is at its lowest amount. 195 202 2014/07/232014/01/82015/06/82014/09/282015/07/25 1394/5/3 2015/09/262015/09/262015/09/202015/11/32015/09/26 1394/7/4 M. Alibolandi M. Alibolandi Imam Khomeini International University Iran Eng.Alibolandi@gmail.com R. Ziaie Moayed R. Ziaie Moayed Imam Khomeini International University Iran Ziaie@eng.ikiu.ac.ir Silt content Liquefaction Cyclic triaxial test Geotextile arrangement [1] Lade P.V., Yamamuro J.A., Effects of non-plastic ﬁnes on static liquefaction of sands. Canadian Geotechnical Journal, 1997; 34, 918–928.##[2] Thevanayagam S., Effect of ﬁnes and conﬁning stress on undrained shear strength of silty sands Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 1998;124, 479–91.##[3] Baziar M. H., Dobry R., Residual strength and large—deformation potential of loose silty sands, JGT ASCE, 1995; 121, 896–906.##[4] Baziar, M. H., Shahnazari, H.,Sharafi A., Laboratory study on the pore pressure generation model for Firouzkoohsilty sands using hollow torsional test. International Journal of Civil Engineering, 2011; 9 (2), 126-134.##[5] Naeini S.A., Baziar M. H., Effect of fines content on steady-state strength of mixed and layered samples of a sand. Journal of Soil Dynamics and Earthquake Engineering, 2004; 24, 181-187.##[6] Polito C.P., Martin J.R., Effects of Nonplastic Fines on the Liquefaction Resistance of Sands. Journal of Geotechnical and Geoenvironmental Engineering, ASCE, 2001; 127, 408-415.##[7] Baziar M.H., Sharafi H., Assessment of Silty Sand Liquefaction Potential Using Hollow Torsional Tests – An Energy Approach, Soil Dynamics and Earthquake Engineering, 2011; 31, 857-865.##[8] Monkul M.M., Yamamuro J.A., Influence of silt size and content on liquefaction behavior of sands. Canadian Geotechnical Journal, 2011; 48, 931 -942.##[9] Sadrekarimi A., Influence of fines content on liquefied strength of silty sands. Soil Dynamics and Earthquake Engineering , 2013; 55, 108–119.##[10] Chandrasekaran B., Broms B., Wong K.S., Strength of fabric reinforced sand under axisymmetric loading. Geotextiles and Geomembranes, 1989; 8, 293-31.##[11] Vercueil D., Billet P., Cordary D., Study of the liquefaction resistance of a saturated sand reinforced with Geosynthetics, Soil Dynamics and Earthquake Engineering, 1997; 16, 417-425.##[12] Athanasopoulos G.A., Effect of particle size on the mechanical behavior of sand-geotextile composites, Geotextiles and Geomembranes, 1993; 12, 255–273.##[13] Krishnaaswamy N.R., Isaac N.T., Liquefaction potential of reinforced sand, Geotextiles and Geomembranes, 1994; 13, 23-41.##[14] Haeri S.M., Noorzad R., Oskoorouchi A.M., Effect of geotextile reinforcement on the mechanical behavior of sand, Geotextiles and Geomembranes, 2000; 18, 385-402.##[15] Moghaddas Tafreshi, S. N. & Asakereh, A., Strength evaluation of wet reinforced silty sand by triaxial test. Iranian Journal of Civil Engineering, 2007; 4, 274-283.## [16] Jin Liu, Gonghui Wang, Toshitaka Kamai, Fanyu Zhang, Jun Yang, Bin Shi, Static liquefaction behavior of saturated fiber-reinforced sand in undrained ring-shear tests, Geotextiles and Geomembranes, Volume 29, Issue 5, October 2011, Pages 462-471##[17] Tuna S.C., Alton S., Mechanical behavior of sand-geotextile interface. Scientica Iranica, 2012; 19, 1044–1051.##[18] Ziaie Moayed R., and Alibolandi M., Influence of geotextile reinforcement on shear modulus of saturated sand, Proceedings of International Workshops on Civil Engineering, 2014, Koc University, Istanbul/Turkey, 99-103##[19] Naeini S.A., Gholampoor N., Cyclic behavior of dry silty sand reinforced with a geotextile, Geotextiles and Geomembranes, 2014; 42,611-619.##[20] Noorzad, R., Amini, F.,Liquefaction resistance of Babolsar sand reinforced with randomly distributed fibers under cyclic loading, Soil Dynamics and Earthquake Engineering Volume 66, November 2014, Pages 281–29.##[21] Sayeed M.A., JanakiRamaiah B., Rawal A., Interface shear characteristics of jute/polypropylene hybrid nonwoven geotextiles and sand using large size direct shear test, Geotextiles and Geomembranes, 2014;42, 63–68. ## [22] Habibi M. R., Shafiee A., Jafari M. K., Monotonic behavior of geotextile reinforced soils under discrete rotation of principal stresses, IJST, Transactions of Civil Engineering, 2014; 38, 325-335.##[23] Naeini S. A., Eftekhari Z, Effect of Geotextile on the Liquefaction Behavior ofSand in Cyclic Triaxial Test, Proceedings of International Workshop on Civil Engineering and Architecture, IWCEA-2014, Istanbul, Turkey, Aug. 2014, P.63-68.## [24] Ghahremani M., Ghalandarzadeh A., Moradi M., Effect of plastic fines on cyclic resistance of saturated sands (in Persian). Journal of Seismology and Earthquake Engineering, 2006; 8, 71-80.##[25] Ghalandarzadeh A., Ahmadi A., Effects of Anisotropic Consolidation and Stress Reversal on the Liquefaction Resistance of Sands and Silty Sands, Geotechnical Engineering Journal of the SEAGS & AGSSEA, 2012; 43, 33-39.##[26] Wong R.T., Seed H.B., Chan C.K., Cyclic loading liquefaction of gravelly soils, Journal of Geotechnical and Geo environmental Engineering, ASCE, 1975;101, 571–583.##[27] Nicholson, R.B. Seed, H.A. Anwar, Elimination of membrane compliance in undrained triaxial testing, measurement and evaluation, Canadian Geotechnical Journal, 1993, 30(5): 727-738.## [28] ASTM D5311-92, Standard Test Method for Load Controlled Cyclic Triaxial Strength of Soil, ASTM International, West Conshohocken, PA, 1992.##[29] Seed H. B., Lee K. L., Liquefaction of Saturated Sands During Cyclic Loading, Journal of the Soil Mechanics and Foundations Division, ASCE, 1966; 92, SM6, Nov., 105--134.##[30] Dobry R.S., Ladd F.Y., Yokel R.M., Chung D., Powell, Prediction of pore water pressure build up and liquefaction of sands during earthquakes by the cyclic strain method. NBS Building Science Series 138, National Bureau of Standards, Gaithersburg, MD, 150 (1982).##[31] Yang, Z., Strength and Deformation Characteristics of Reinforced Sand, Ph.D. Thesis, 1974.##[32] Thevanayagam S., Ravishankar K., Mohan, S., Effects of ﬁnes on monotonic undrained shear strength of sandy soils, Geotech. Test GTJODJ, 1997; 20, 394–406.##[33] ASTM D4833 (2013) Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products##[34] ASTM D4595 (2011) Standard Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method.##[35] ASTM D5261 (2010) Standard Test Method for Measuring Mass per Unit Area of Geotextiles##[36]ASTM D5199 (2012) Standard Test Method for Measuring the Nominal Thickness of Geosynthetics## ##

Some studies on the effect of fly ash and lime on physical and mechanical properties of expansive clay 2 2 Fly ash is one of the most plentiful and versatile of the industrial by-products. At present, nearly 150 million tonnes of fly ash is being generated annually in India posing dual problem of environmental pollution and difficulty in disposal. This calls for establishing strategies to use the same effectively and efficiently. However, it is only in geotechnical engineering applications such as the construction of embankments/dykes, as back fill material, as a sub-base material etc., its large-scale utilization is possible either alone or with soil. Soil stabilization can be achieved by various means such as compaction, soil replacement, chemical improvement, earth reinforcement etc. Usually, in the case of clay soils, chemical improvement is commonly most effective since it can strengthen the soil, to remove its sensitivity both to water and its subsequent stress history. Among chemical means or additives, fly ash/lime provides an economic and powerful means of improvement, as demonstrated by the significant transformation that is evident on mixing with heavy clay. In the present investigation, different percent fly ashes (10%, 20%, 40%, 60% & 80%) were added to a highly expansive soil from India by dry weight of the natural soil, and subjected to various tests. The important properties that are necessary for using fly ash in many geotechnical applications are index properties, compaction characteristics, compressibility characteristics, permeability and strength. Based on test results, it has been found that using fly ash for improvement of soils has a two-fold advantage. First, to avoid the tremendous environmental problems caused by large scale dumping of fly ash and second, to reduce the cost of stabilization of problematic/marginal soils and improving their engineering properties for safe construction of Engineering Structures. 203 212 2014/07/232014/01/82015/06/82014/09/282015/07/252015/09/24 1394/7/2 2015/09/262015/09/262015/09/202015/11/32015/09/262015/11/3 1394/8/12 B.A. Mir B.A. Mir Department of Civil Engineering, National Institute of Technology Srinagar India p7mir@nitsri.net Solid waste material Waste management Expansive soils Soil Stabilization Environmental problems Physical &amp mechanical properties [1]. Ghais, A. and Abadi, A., Fly Ash Utilization in Soil Stabilization. Procc. International Conference on Civil, Biological and Environmental Engineering (CBEE-2014), Istanbul (Turkey), 2014, pp. 76-78.##[2]. Chen, F. H., Foundations on expansive soils, Elsevier, Amsterdam, The Netherlands, 1975.##[3]. Holtz, W. G. and Gibbs, H. J., Engineering properties of expansive clays, Transaction of American society of civil engineers, 1954, No. 121, pp. 641-677.##[4]. Gromko, G. J., Review of expansive soils, Journal of Geotechnical Engineering Division, ASCE, 1974, 100, pp, 667-787.##[5]. Ferguson, G., Use of self-cementing fly ashes as a soil-stabilizing agent, Proceedings of Session on fly ash for soil improvement, ASCE, Geotechnical Special Publication, 1993, 36, pp. 1-14.##[6]. Mir, B. A., Effect of fly ash on the Engineering Properties of BC soils, M. E. Thesis, 2001; Deptt. of Civil Engineering IISc, Bangalore. ##[7]. Zha, F., Liu, S., Du, Y. and Cui, K., Behavior of expansive soils stabilized with fly ash Natural Hazards, Springer, 2008, 47, pp. 509–523. ##[8]. Bose B., Geo-Engineering Properties of Expansive Soil Stabilized with Fly Ash. EJGE, 2012, Vol. 17, pp. 1339-1353, Bund. J.##[9]. Cokca, E., Use of class C fly ash for the stabilization of an expansive soil, Jl. of Geotech. and Geoenvironmental Eng., 2001, 127(7), pp. 568-573.##[10]. Bhuvaneshwari, S., Robinson, R. G. and Gandhi, S. R., Stabilization of Expansive Soils using Fly ash. Fly Ash India 2005- Fly Ash Utilization Programme (FAUP), TIFAC, DST, New Delhi, pp. 5.1-5.10.##[11]. Nalbantoglu, Z., Effectiveness of Class C fly ash as an expansive soil stabilizer. Construction and Building Materials, Elsevier Ltd., 2014, 18, pp. 377–381.##[12]. Martin, J. P., Collins, R. A., Browings, J. S. and Biehl, F. J., Properties and use of fly ashes for embankments,” Journal, Energy Engg., 1990; vol. 166(2), pp 71- 85.##[13]. Rajakumar, C. and Meenambal, C. T., Effect of Coal Ash in the Stabilization of Expansive Soil for the Pavement. International Journal of ChemTech Research, 2015, 8(1), pp 170-177.##[14]. Turgeon, R., Fly ash fills a valley, Civil Engineering, ASCE, New York, 1988; pp. 58-67.##[15]. Ahmed, N. A .K., Damgir, R. M. and Hake, S. L., Effect of Fly ash and RBI Grade 81 on Black Cotton soil as a sub grade for Flexible Pavements, International Journal of Innovations in Engineering and Technology, 2014, Vol. 4, Issue 1, pp. 124-130.## [16]. Indraratna, B., Nutalaya, P. and Kuganenthira, N., Stabilization of a dispersive soil by blending with fly ash, Q. J. Engg. Geol. 1991, 24, pp. 275 – 290.##[17]. Uppal, H. L. and Dhawn, P. K., A resume on the use of fly ash in soil stabilization, Road Research Papers, 1968, 95, pp. 1 – 12.##[18]. Puppala, A. J. Fibre and fly ash stabilization methods to treat soft expansive soils, Geotechnical Special Publication, 2001, Vol.112, pp. 136-145.##[19]. Kate, J. M., Strength and volume change behavior of expansive soils treated with fly ash. GeoFrontiers-2005, ASCE, Geotechnical Special Publication, pp. 1-15.##[20]. Gourav, D., Kumar, D. and Priyadarshee, A., Effect of Fly Ash on the Properties of Black Cotton Soil: A Review. International Journal of Advanced Technology in Engineering and Science, 2015, Vol.03, Special Issue No. 02, pp. 596-604.##[21]. Pandian N. S., Fly ash characterization with reference to geotechnical applications, J. Indian Inst. Sci., 2004, 84, pp.189–216, Indian Institute of Science Bangalore.##[22]. Sridharan, A., Prashanth, J. P. and Sivapullaiah P. V., Effect of fly ash on the unconfined compressive strength of black cotton soil, Proceedings of the ICE – Ground Improvement, 1997, 1(3), pp. 169 -175.## [23]. Kumar, A., Walia, B.S. and Bajaj, A., Influence of fly ash, lime and polyester fibers on compaction and strength properties of expansive soil, Journal of materials in Civil Engineering, 2007, Vol. 19, Issue 3, pp. 242-248.##[24]. Saha, S. and Pal, S. K., Influence of Fly Ash on Unconfined Compressive Strength of Soil and Fly Ash Layers Placed Successively. Electronic Journal of Geotechnical Engineering, 2013, 18, Bund. H, pp. 1593-1602.##[25]. Satyanarayana, K, Hemanth, P. V. V. Praveen, S. P. and Kumar, S. B. V., A Study on Strength Characteristics of Expansive Soil-Fly ash Mixes at Various Molding Water. International Journal of Recent Technology and Engineering, 2013, 2 (5), pp. 145-149. ##[26]. Verma S. K. And Maru S., Behavioral Study of Expansive Soils and its Effect on Structures–A Review. International Journal of Innovations in Engineering and Technology, 2013, 2(2), pp. 228-238. ##[27]. Mir, B. A. and Sridharan, A., Physical and compaction behavior of clay soil-fly ash mixtures, International Journal of Geotechnical and geological Engineering, 2013, 31(4), pp. 1059-1072.##[28]. Phanikumar, B.R., Nagareddayya, S. and Sharma, R.S., Volume change behavior of fly ash- treated expansive soils. Proc., 2nd Int. Conf. on Civil Engineering, Indian Inst. of Science, Bangalore, India, 2001, 2, pp. 689 – 965. ##[29]. Phanikumar, B. R. and Sharma, R. S., Volume change behavior of fly ash-stabilized clays, Journal of Materials in Civil Engineering, 2007, pp. 67-74.##[30]. Phanikumar, B. R., Effect of lime and fly ash on swell consolidation and shear strength characteristics of expansive clays: A comparative study, Jl. of Geomechanics and Geoengineering: An international journal, 2009, 4(2), pp. 175-181.##[31]. Mir, B. A. and Sridharan, A., Volume change behaviour of clayey soil–fly ash mixtures, International Journal of Geotechnical Engineering, 2014, 8(1), pp. 72-83.##[32]. ASTM C618-12a, Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete, ASTM International, West Conshohocken, PA, 2012, www.astm.org.##[33]. ASTM D421-85(2007), Standard Practice for Dry Preparation of Soil Samples for Particle-Size Analysis and Determination of Soil Constants, ASTM International, West Conshohocken, PA, 2007, www.astm.org. ##[34]. ASTM D2217-85(1998), Standard Practice for Wet Preparation of Soil Samples for Particle-Size Analysis and Determination of Soil Constants, ASTM International, West Conshohocken, PA, 1998, www.astm.org.##[35]. ASTM D 2487-06, Standard procedure for classification of soils for engineering purposes, Annual Book of ASTM Standards, American society for testing and materials, Philadelphia, 2006, Vol. 04-08, West Conshohocken, PA. www.astm.org##[36]. ASTM D422-63(2007)e2, Standard Test Method for Particle-Size Analysis of Soils, ASTM International, West Conshohocken, PA, 2007, www.astm.org ##[37]. ASTM D5239-12, Standard Practice for Characterizing Fly Ash for Use in Soil Stabilization, ASTM International, West Conshohocken, PA, 2012, www.astm.org.##[38]. ASTM C311 / C311M-13, Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use in Portland-Cement Concrete , ASTM International, West Conshohocken, PA, 2013, www.astm.org ##[39]. ASTM D 854-14, Standard Test method for specific gravity of soil solids. Annual Book of ASTM Standards, American Society for Testing and Materials, Philadelphia, Vol. 04.08; 2014, www.astm.org.##[40]. Pandian, N. S., Rajasekhar, C. and Sridharan, A., Studies of the specific gravity of some Indian coal ashes, Journal of testing and evaluation, JTEA, 1998, 26(3), pp. 177-186.##[41]. ASTM D4318-10E1, Standard test methods for liquid limit, plastic limit, and plasticity index of soils, Annual Book of ASTM Standards, American society for testing and materials, Philadelphia,2010, www.astm.org.##[42]. ASTM D427-04, Test Method for Shrinkage Factors of Soils by the Mercury Method, ASTM International, West Conshohocken, PA, 2004, www.astm.org. ##[43]. ASTM D698-12e2, Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort, ASTM International, West Conshohocken, PA, 2012, www.astm.org. ##[44]. ASTM D4546-14, Standard Test Methods for One-Dimensional Swell or Collapse of Soils, ASTM International, West Conshohocken, PA, 2014, Vol. 04.08, www.astm.org.##[45]. Sridharan A, and Prakash, K., Classification procedures for expansive soils. Proc. Inst. of Civ. Eng. (UK), 2000, 143, pp. 235–240.##[46]. Mir, B. A., Effect of Fly Ash on Swelling Potential of BC Soil, Proceedings of Indian Geotechnical Conference (IGC-2013), 2013, Theme No 4, Paper No. 120, pp. 1-9, Roorkee##[47]. ASTM D2435 / D2435M-11, Standard Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental Loading, ASTM International, West Conshohocken, PA, 2011, www.astm.org. ##[48]. ASTM D2166 / D2166M-13, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil, ASTM International, West Conshohocken, PA, 2013, www.astm.org.## ##

Accounting for soil nonlinearity in three-dimensional seismic structure-soilstructure-interaction analyses of adjacent tall buildings structures 2 2 The interactive effects of adjacent buildings on their seismic performance are not frequently considered in seismic design. The adjacent buildings, however, are interrelated through the soil during seismic ground motions. The seismic energy is redistributed in the neighboring buildings through multiple structure-soil-structure interactions (SSSI). For example, in an area congested with many nearby tall and/or heavy buildings, accounting for the proximity effects of the adjacent buildings is very important. To solve the problem of SSSI successfully, researchers indicate two main research areas where need the most attention: 1) accounting for soil nonlinearity in an efficient way, and 2) spatial analysis of full 3D soil-structure models. In the present study, three-dimensional finite element models of tall buildings on different flexible foundation soils are used to evaluate the extent of cross interaction of adjacent buildings. Soil nonlinearity under cyclic loading is accounted for by Equivalent Linear Method (ELM) as to conduct large parametric studies in the field of seismic soil-structure interaction, the application of ELM is preferred over other alternatives (such as application of complicated constitutive soil models) due to the efficiency and reliability of its results. 15 and 30 story steel structures with pile foundations on two sandy and clayey sites are designed according to modern codes and then subjected to several actual earthquake records scaled to represent the seismicity of the building sites. Results show the cross interaction of adjacent buildings on flexible soils, depending on their proximity, increases dynamic displacements of buildings and reduces their base shears. 213 225 2014/07/232014/01/82015/06/82014/09/282015/07/252015/09/242014/06/3 1393/3/13 2015/09/262015/09/262015/09/202015/11/32015/09/262015/11/32015/09/20 1394/6/29 M.A. Rahgozar M.A. Rahgozar University of Isfahan Iran rahgozar@eng.ui.ac.ir Equivalent linear method (ELM) Structure-soil-structure interaction Adjacent tall buildings structures Frequency content High amplitude records Low amplitude records [1] Mylonakis G, Gazetas G, Nikolaou S, Michaelides O. The role of soil on the collapse of 18 piers of the hanshin expressway in the kobe earthquake, Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, 2000, Vol. 1, pp. 28-34.##[2] Saadeghvaziri MA, Yazdani-Motlagh AR, Rashidi S. Effects of soil-structure interaction on longitudinal seismic response of MSSS bridges, Soil Dynamics and Earthquake Engineering, 2000, Nos. 1-4, Vol. 20, pp. 231-242.##[3] Inaba T, Dohi H, Okuta K, Sato T, Akagi H. Nonlinear response of surface soil and NTT building due to soil-structure interaction during the 1995 Hyogo-ken Nanbu (Kobe) earthquake, Soil Dynamics and Earthquake Engineering, 2000, Nos. 5-8, Vol. 20, pp. 289-300.##[4] Halabian AM, El Naggar HM. Effect of non-linear soil-structure interaction on seismic response of tall slender structures, Soil Dynamics and Earthquake Engineering, 2002, No. 8, Vol. 22, pp. 639-658.##[5] Tongaonkar NP, Jangid RS. Seismic response of isolated bridges with soil–structure interaction, Soil Dynamics and Earthquake Engineering, 2003, No. 4, Vol. 23, pp. 287-302.##[6] Dutta SC, Bhattacharya K, Roy R. Response of low-rise buildings under seismic ground excitation incorporating soil–structure interaction, Soil Dynamics and Earthquake Engineering, 2004, No. 12, Vol. 24, pp. 893-914.##[7] Nakhaei M, Ghannad MA. The effect of soil-structure interaction on damage index of buildings, Engineering Structures, 2008, No. 6, Vol. 30, pp. 1491-1499.##[8] Raychowdhury P. Seismic response of low-rise steel moment-resisting frame (SMRF) buildings incorporating nonlinear soil–structure interaction (SSI), Engineering Structures, 2011, No. 3, Vol. 33, pp. 958-967.##[9] Saez E, Lopez-Caballero F, Modaressi A. Effect of the inelastic dynamic soil–structure interaction on the seismic vulnerability assessment, Structural Safety, 2011, No. 1, Vol. 33, pp. 51-63.##[10] Clouteau D, Broc D, Devesa G, Guyonvarh V, Massin P. Calculation methods of Structure – Soil - Structure Interaction (3SI) for embedded buildings: Application to NUPEC tests, Soil Dynamics and Earthquake Engineering, 2012, No. 1, Vol. 32, pp. 129-142.##[11] Lou M, Wang H, Chen X, Zhai Y. Structure-soil-structure interaction: Literature review, Soil Dynamics and Earthquake Engineering, 2011, No. 12, Vol. 31, pp. 1724-1731.##[12] Kramer SL. Geotechnical Earthquake Engineering, Prentice-Hall Inc, New Jersey, 1996.##[13] American Society of Civil Engineers. ASCE7, Minimum design loads for buildings and other structures, American Society of Civil Engineers, Virginia, 2010.##[14] American Institute of Steel Construction (AISC) Specification for structural steel buildings, ANSI, AISC 360, One East Wacker Drive, Suite 700, Illinois, 2005.##[15] Tomlinson MJ. Pile design and construction practice, Fourth edition, E & FN Spon, An Imprint of Chapman & Hall, London, 1994.##[16] Seed HB, Idriss IM. Soil Moduli and Damping Factors for Dynamic Response Analysis, Report No. EERC 70-10, University of California, Berkeley, 1970.##[17] Ordonez GA. SHAKE2000, A computer program for the 1-D analysis of geotechnical earthquake engineering problems, 2006.##[18] University of California, Berkeley, OpenSees, Open system for earthquake engineering simulation, user manual, University Avenue Berkeley, California, 2009.##[19] Pacific Earthquake Engineering Research (PEER) center, http://peer.berkeley.edu/, 2014.##[20] Wolf JP. Dynamic soil structure interaction, Prentice-Hall Inc, New Jersey, 1985.## ##