بررسی تأثیر سیمان پرتلند و نانو رس بر پتانسیل فروریزش و شاخص‌های تحکیم خاک فروریزشی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه ژئوتکنیک، دانشکده مهندسی عمران، آب و محیط زیست، دانشگاه شهید بهشتی، پردیس فنی و مهندسی شهید عباسپور، تهران، ایران

2 کارشناسی ارشد مهندسی عمران، ژئوتکنیک، دانشگاه علم و فرهنگ،تهران، ایران

چکیده

فروریزش، کاهش حجم ناگهانی خاک با افزایش رطوبت است که در اثر از بین رفتن مقاومت عوامل پیونددهنده ذرات رخ می‌دهد. خاک‌های فروریزشی در مناطق وسیعی از جهان و در نواحی گرمسیری ایران، یافت می‌شوند. وقوع فروریزش می‌تواند خسارت‌های زیادی به تاسیسات و سازه‌های مجاور خاک تحمیل کند. بنابراین مطالعه رفتار خاک‌های فروریزشی از اهمیت ویژه‌ای برخوردار است. در این تحقیق تثبیت خاک فروریزشی منطقه سرکویر سمنان که از نوع الی با پیوندهای ضعیف رسی است، توسط سیمان پرتلند و نانو رس مورد مطالعه قرار گرفت. سیمان به مقدار 0/5 ،1 و 2/5 و نانو رس به مقدار 0/05 ،0/01و 0/25 درصد وزنی خاک خشک، به خاک فروریزشی اضافه شدند. نمونه‌ها با دانسیته نسبی 14 کیلونیوتون بر متر مکعب و درصد رطوبت 5 ،%آماده شدند. با انجام آزمایش تحکیم بر روی نمونه‌های به‌سازی شده پس از 7 ،14 و 28 روز، شاخص فروریزش مطابق با استاندارد  ASTM D 5333    تعیین شد. نتایج نشان داد که هر دو ماده سیمان و نانو رس می‌توانند پتانسیل فروریزش را کاهش دهند. عملکرد بهسازی بهطور قابل توجهی به مقدار ماده افزودنی و نیز زمان عمل‌آوری وابسته بود. بهترین عملکرد بهسازی در مقادیر پائین نانو رس مشاهده شد و با افزایش مقدار نانو رس، بازده بهسازی کاهش یافت. برخلاف سیمان، فرآیند ً سریع بود و با تبخیر آب درون خاک، تکمیل شد. علاوه بر این، در این تحقیق با تثبیت با نانو رس نسبتا عکس‌برداری میکروسکوپی از نمونه‌های بهسازی شده و بهسازی نشده، رفتار خاک از دیدگاه میکرومکانیک نیز مورد ارزیابی قرار گرفت.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Investigating the effect of Portland cement and Nano-clay on the collapse potential and consolidation indexes of the collapsible soil

نویسندگان [English]

  • Mostafa Zamanian 1
  • Fatemeh Qahremani 2
1 Department of Civil, Water, and Environmental Engineering, Shahid Beheshti University, Tehran, Iran
2 Master of Geotechnical Engineering, University of Science and Culture
چکیده [English]

Collapse refers to a sudden decrease in the soil volume upon wetting which is attributed to a loss in the strength of the inter-particle bonds. Collapsible soils can be founded in vast areas around the word and subtropical areas of Iran. Collapse characteristics contribute to various problems to infrastructures that are constructed on loess soils. For this reason, the collapse behavior of loess soils has been the subject of interest. In this study, stabilization of Semnan loess which is composed of fine sand and silt bonded by weak clay bonds, has been investigated. The loess was mixed with Portland cement in the order of 0.5%, 1%, and 2.5% for and with nano-clay in order of 0.05%, 0.1%, and 0.25%. The specimens were prepared to achieve a dry density of 14 kN/m3 and a water content of 5%. Oedeometer tests were performed to determine the collapse potential according to ASTM D5333 after 7, 14, and 28 days. Results showed that both Portland cement and nano-clay could reduce collapse potential. Improvement performance was significantly dependent on the binder content and curing time. The best improvement performance was observed at low nano-clay content and it was reduced by increasing nano-clay content. Unlike the cement stabilization, treatment process with nano-clay was relatively fast that terminated when soil moisture content was evaporated. In addition, in this study, micromechanical soil behaviors were investigated by scanning electron microscopy (SEM) image of the treated and untreated specimens.

کلیدواژه‌ها [English]

  • Collapsible soil
  • Collapse potential
  • Soil improvement
  • Portland cement
  • Nano-clay

مراجع

[1]  A. El Howayek, P.-T. Huang, R. Bisnett, M.C. Santagata, Identification and behavior of collapsible soils, (2011).
[2]  H.H. Abdel-Mohsen, A. Ali, Performance of partially replaced collapsible soil Part 1: Laboratory Study, in:International Conference on Advances in Structural and Geotechnical Engineering, 2015, pp. 9-6.
[3]  M. Ayeldeen, A. Negm, M. El-Sawwaf, M. Kitazume, Enhancing mechanical behaviors of collapsible soil using two biopolymers, Journal of Rock Mechanics and Geotechnical Engineering, 339-329 (2017) (2)9.
[4]  S.M. Haeri, A.A. Garakani, A. Khosravi, C.L. Meehan, Assessing the hydro-mechanical behavior of collapsible soils using a modified triaxial test device, Geotechnical Testing Journal, 204-190 (2013) (2)37.
[5]  S.M. Haeri, Hydro-mechanical behavior of collapsible soils in unsaturated soil mechanics context, Japanese Geotechnical Society Special Publication, -25 (2016) (1)2 40.
[6]  K.E. Gaaver, Geotechnical properties of Egyptian collapsible soils, Alexandria Engineering Journal, (3)51 210-205 (2012).
[7]  L. Barden, A. McGown, K. Collins, The collapse mechanism in partly saturated soil, Engineering Geology, 60-49 (1973) (1)7.
[8]  K. Abbeche, O. Bahloul, T. Ayadat, A. Bahloul, Treatment of collapsible soils by salts using the double consolidation method, in: Experimental and Applied Modeling of Unsaturated Soils, 2010, pp. 78-69.
[9]  A.A. Basma, E.R. Tuncer, Evaluation and control of collapsible soils, Journal of Geotechnical Engineering, 1504-1491 (1992) (10)118.
[10] A. Klukanova, J. Sajgalik, Changes in loess fabric caused by collapse: an experimental study, Quaternary International, 39-35 (1994) 24.
[11] C. Rogers, Types and distribution of collapsible soils, in: Genesis and properties of collapsible soils, Springer, 1995, pp. 17-1.
[12] A. Assallay, I. Jefferson, C. Rogers, I. Smalley, Fragipan formation in loess soils: development of the Bryant hydroconsolidation hypothesis, Geoderma, (2-1)83 16-1(1998).
[13] C. Chiu, C. Ng, C. Shen, Collapse behavior of loosely compacted virgin and non-virgin fills in Hong Kong, in: Proc. 2nd Int. Conf. Unsaturated soils, 1998, pp. 30-25.
[14] C. Ng, C. Chui, C. Shen, Effects of wetting history on the volumetric deformations of an unsaturated loose fill, in: Proceedings of the 13th Southeast Asian Geotechnical Conference, Taipei, Taiwan, 1998, pp. 146-141.
[15] Alkandari, F. A.," Collapse of Cemented Carbonate Sand", Ph. D. thesis, Department of Civil, Environmental and Architectural Engineering, University of Colorado, USA, (2000)
[16]Elkady, T. Y." Static and dynamic behaviour of collapsible soils". Ph. D. Thesis, Arizona State University, USA, (2002).
[17] M.M. Futai, M. De Souza Scares de Almeida, Collapsible soil: a theoretical and experimental study, Electronic Journal of Geotechnical Engineering, 16 (2002) 7.
[18] A. BAGHERIE, A. FARSIJANI, CONSOLIDATION BEHAVIOR OF COLLAPSIBLE CLAYEY SOILS IN SATURATED AND UNSATURATED CONDITIONS, (2016). (in Persian)
[19]G. Evans, D. Bell, Chemical stabilization of loess, New Zealand, in: Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering, 1981, pp. 658-649.
[20] R.H. Borden, R.O. Holtz, I. Juran, Grouting, soil improvement and geosynthetics, in, ASCE, 1992.
[21] F.N. Okonta, T. Manciya, Compaction and strength of lime–fly Ash stabilized collapsible residual sand, (2010).
[22] S. Huangjing, W. Gasaluck, The stabilization of loess by chemical additives for road base, EJGE, -1651 (2010) 15 1668.
[23] R. Moayed, E. Izadi, S. Heidari, Stabilization of saline silty sand using lime and micro silica, Journal of Central South University, 3011-3006 (2012) (10)19.
[24] Y. Zhang, Z. Zhang, Influence factor analysis on strength of lime-fly ash loess, Engineering, 561 (2013) (06)5.
[25] L.H. Mei, W.L. Min, G. Peng, The mechanical properties of cement reinforced loess and Pore microstructure characteristics, Applied Mechanics & Materials, ((527 2014.))
[26] A. Khelifa, L. Azeddine, B. Ouassila, Treatment of Collapsible Soils by Cement Using the Double Consolidation Method, in: International Congress and Exhibition” Sustainable Civil Infrastructures: Innovative Infrastructure Geotechnology”, Springer, 2017, pp. 88-76.
[27] R.N. Angelova, Loess-cement long-term strength-a facilitating factor for loess improvement applications, Geologica Balcanica, 24-21 (2007) (4-3)36.
[28]  F. Sariosseiri, B. Muhunthan, Geotechnical properties of Palouse loess modified with cement kiln dust and Portland cement, in: GeoCongress 2008: Characterization, Monitoring, and Modeling of GeoSystems, 2008, pp. -92 99.
[29]  P. Arrúa, G. Aiassa, M. Eberhardt, B.C. Alercia, Behavior of collapsible loessic soil after interparticle cementation, International journal of Geomate, 2(1 SERL -130 )2011 2 136.
[30]  A.-M. Mohamed, M. El Gamal, Treatment of collapsible soils using sulfur cement, International Journal of Geotechnical Engineering, 77-65 (2012) (1)6.
[31]  R. Noorzad, H. Pakniat, Investigating the effect of sample disturbance, compaction and stabilization on the collapse index of soils, Environmental Earth Sciences, (18)75 1262 (2016).
[32] Z.H. Majeed, M.R. Taha, A review of stabilization of soils by using nanomaterials, Australian Journal of Basic and Applied Sciences, 581-576 (2013) (2)7.
[33] G. Zhang, Soil nanoparticles and their influence on engineering properties of soils, in: Advances in Measurement and Modeling of Soil Behavior, 2007, pp. 13-1.
[34] s. sohrabi shegefti, h. musavi jahromi, E.M. Super Repair s’effect on the strength parameters of the collapsible soils, Amirkabir Journal of Civil Engineering, -97 (2014) (1)46 106. (in Persian)
[35] M.R. Noll, C. Bartlett, T.M. Dochat, In situ permeability reduction and chemical fixation using colloidal silica, in: Proceeding of the Sixth National Outdoor Action Conference on Aquifer Restoration, Ground Water Monitoring, and Geophysical Method, National Ground Water Association, 1992, pp. 457-443.
[36] P.M. Gallagher, Y. Lin, Column testing to determine colloidal silica transport mechanisms, in: Innovations in grouting and soil improvement, 2005, pp. 10-1.
[37] H.H. Karim, T. Schanz, M.H. Nasif, Improving collapsibility and compressibility of gypseous sandy soil using bentonite and kaolinite, Engineering and Technology Journal, 3153-3141 (2012) (18)30.
[38] A. Vakili, Evaluation of the lime and cement effect on the mechanical and physical characteristics of the collapsible soils, J. Basic. Appl. Sci. Res, 696-691 (2013) (8)3.
[39] L.H. Mei, W.L. Min, G. Peng, The mechanical properties of cement reinforced loess and Pore microstructure characteristics, Applied Mechanics & Materials, ((527 2014)).
[40] S.M. Haeri, A. Mohammad Hosseini, M.M. Shahrabi, S. Soleymani, Comparison of strength characteristics of Gorgan loessial soil improved by nanosilica, lime and Portland cement, in: 15th Pan American Conference on Soil Mechanics and Geotechnical Engineering, 2015.
[41] M. A., Khodabandeh, M. Keramati, S. M. Hosseini, S. Nokandeh, Evaluation of the Effect of the leachate’s pH on the rate of collapse and shear strength parameters of collapsible soils, Amirkabir journal of civil engineering, (2018), inPress. (in Persian)
[42] F. Davoudi, Experimental Study of collapsible soils Improvement Using Nanoclay, Msc Thesis, Persian Gulf University, Bushehr, Iran, 1394. (in Persian)
[43] B. Iranpour, A. Haddad, The influence of nanomaterials on collapsible soil treatment, Engineering Geology, 205 53-40 (2016).
[44]  ASTM D " .03-5333Standard test methods for measurement of collapse potential of soils2003) ,").
[45]  M.R. Taha, O.M.E. Taha, Influence of nano-material on the expansive and shrinkage soil behavior, Journal of Nanoparticle Research, 1190 (2012) (10)14.
[46]   R. Ladd, Preparing test specimens using undercompaction, Geotechnical Testing Journal, 23-16 (1978) (1)1.
 
نشریه مهندسی عمران امیرکبیر
دوره 52، شماره 6
شهریور 1399
صفحه 1439-1454

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