میزان رسوب در ستون‌های زهکش ماسه‌ای بعد از انجام زهکشی در خاک

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

گروه خاک، دانشکده مهندسی عمران، دانشگاه سمنان

چکیده

یکی از مسائل مرتبط با ستون‌های زهکش بحث انسداد در آن‌ها می‌باشد. در ستون‌های زهکش به ­دلیل ورود ذرات ریزدانه از خاک اطراف به داخل ستون زهکش، منافذ به مرور مسدود می‌گردند. در این تحقیق چهار ستون زهکش به­ کمک سلول ساخته شده مورد آزمایش قرار گرفت، که شامل ستون‌های تک­ مصالح و ستون‌های مخلوط می‌باشند. بر روی هر نمونه، 8 آزمایش انجام شده. مصالح مورد استفاده در این ستون‌ها شامل 3 اندازه ماسه به قطر میانگین 5/0، 75/0 و 1 سانتی‌متر است. به ­منظور بررسی عملکرد میزان رسوب، خاک با آب مخلوط شده، که درصد اختلاط این ریزدانه با آب 0، 5، 5/7 و 10 درصد از وزن آب است. در تمام آزمایش‌ها جریان آب، با هد 1 متر وارد ستون‌های زهکش شده و پس از عبور از ستون از آن خارج شده است. نتایج آزمایش‌ها نشان می‌دهد میزان رسوب در ستون‌های زهکش، به نوع جنس مصالح، نسبت تخلخل مؤثر، نسبت تخلخل غیر مؤثر، نسبت تخلخل اولیه، اصطکاک بین مصالح داخل ستون با ریزدانه مخلوط در آب، حفرات در سطح مصالح، زبری و شکل هندسی مصالح می‌باشد. رسوب در ستون‌های زهکش باعث کاهش نسبت تخلخل، کاهش عبور جریان، افزایش اصطکاک داخلی و ایجاد پل‌های ارتباطی بین ریزدانه و در نتیجه انسداد و از بین رفتن عملکرد زهکشی ستون می‌شود. دانه­ بندی خاک قبل و بعد انجام آزمایش نشان­ دهنده‌ این است که ذرات عبوری از الک 200 به ­طور کلی از نمونه‌ها عبور کرده و بیشترین وزن ذرات رسوب کرده، ذرات بزرگتر از 5/0 میلی‌متر می‌باشد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

The Amount of Sediment in Sand Drainage Columns after Drainage in the Soil

نویسندگان [English]

  • Amirhossein Pashaie
  • Adel Asakereh
  • Abdolhossein Haddad
Civil Engineering Department, Semnan University, Semnan, Iran
چکیده [English]

Historically for geotechnical engineers, the design and construction of structures on soft soil sediments has been a challenge. The ability to serve and limit the conditions as well as the cost and time program is considered. To meet these requirements, many types of construction methods are available. For example, replacing soft soil with other materials, reinforcing embankment, using lightweight filling materials, prefabricated vertical drainage and overhead or suction to accelerate consolidation, stage density, use of stone columns or different options from cement and cement mixture The soil is like a deep mixing or candle with reinforced reinforcement. Among all existing construction methods, the use of stone columns in soft soil is one of the most common things to reduce session and improve stability and freight capacity. However, when the stone columns are installed in very soft soils, it results in excessive clay pouring into the inner parts of the stone columns and reduces its stone column bearing capacity as well as its drainage capacity (Almeida, 2019). The stone column obstruction has been widely reported and its obstruction on the amount of soft soil improved with the stone columns is visible (Tai and Zhou, 2019) The use of stone columns is a popular technique in improving land with fine soil that can easily Reduce drainage and time of consolidation, as well as increased hardness and shear resistance (Indraratna, 2017). Vertical drainage, such as prefabricated drainage, sand drainage, stone columns and pebbles that are commonly used to accelerate or increase soil resistance. Many previous studies have reported that the area of the impact and resistance of the well causes excess water pressure in the soft soil to be improved with drainage (Nguyen, 2020). The stone column contains empty space or pores. The microphones are attached to the surface of the pores, through which penetrating water flows. Studies show that hydrodynamic or colloidal force is generally responsible for separating the microphones from the pores (Survi and Kousik, 2018). Stone columns create drainage paths due to high permeability (Weber et al., 2010).

کلیدواژه‌ها [English]

  • Drainage columns
  • Void ratio
  • Sedimentation
  • Permeability
  • Slurry

مراجع

Adams K, Networks, 2017, july 18, (2nd edstor.) [online]. Available: https://www.hunker.com/13424513/size-type-of gravel-for-a-french-drain
Almeida M, “Generalities” in Geosynthetic Encased Columns for Soft Soil Improvement, Ed. Netherlands: Taylor & Francis Group, 2019, 1-6, ISBN: 978-1-315-17714-4.
Balzer M, “Identification of the growth defects responsible for pitting corrosion on sputter coated steel samples by Large Area High Resolution mapping”, Thin Solid Films, 2015, 581 99-106. https://doi:10.1016/j.tsf.2014.12.014.
Brand W, Gendig C, “Corrosion behaviour of hybrid coatings”, 1996, 291, 343-347.
Bryan A, “A review of field performance of stone columns in soft soils. Geotechnical Engineering, Issue”, 2009, GE6, 323-334. https://doi.org/10.1680/geng.2009.162.6.323
Creus J, Idrissi H, Mazille H, Sanchette F, Jacquot F, “Improvement of the corrosion resistance of CrN coated steel by an interlayer”, Surf, Coatings Technol . 107 183-190. 1998. doi:10.1016/S0257-8972(98)00646-X.
Das BM, “Geotechnical properties and exploration of soil in principles of foundation engineering”, Eighth Edition, Das, B.M. United States of America, Cengage Learning, 2014, 5-75.
Doan S, “Analytical solution for free strain consolidation of stone column-reinforced soft ground considering spatial variation of total stress and drain resistance”, Computers and Geotechnics, 2020. https://doi.org/10.1016/j.compgeo.2019.103291
Fausey N, “Drainage”, In Drainage, Surface and Subsurface, Ed. USA: Elsevier, 2005, 409-413. https://doi.org/10.1016/B0-12-348530-4/00352-0
Han J, Principles and practice of ground improvement. John Wiley & Sons, 2015.
Indraratna B, “Experimental simulation and mathematical modelling of clogging in stone Column”, Canadian Geotechnical Journal, 2017, 1-39.
Indraratna B, “Numerical solution of stone column-improved soft soil considering arching, clogging, and smear effects”, Journal of Geotechnical and Geoenvironmental Engineering, 2013.doi:10.1061/(ASCE)GT.1943-5606.0000789.
Kerry R, Armstrong D, “Particle size and clogging of granular media permeted with leachate”, Journal of Geotechnical and Geoenvironmental Engineering, 2000, 126, 775-786.
Kerry R, Yu Y, “Factors affecting the clogging of leachate collection systems in msw landfills, International Congress on Environmental Geotechnics,2010, 6, 1-23.
Konyashin IY, Chukalovskaya TV, “A technique for measurement of porosity in protective coatings, Surf”, Coatings Technol, 1997, 5-11. doi:10.1016/S0257-8972(95)02758-0.
Liu C, Leyland A, “EIS comparison on corrosion performance of PVD TiN and CrN coated mild steel in 0.5 N NaCl aqueous solution”, Corrosion Science, 2001, 43, 1953-1961.doi:10.1016/S0010-938X(00)00188-8.
Liu C, Leyland A, Matthews A, “Corrosion resistance of multi-layered plasma-assisted physical vapour deposition TiN and CrN coatings”, Surface and Coatings Technology, 2001, 164-173.doi:10.1016/S0257-8972(01)01267-1.
Nguyen P, “Large-strain analysis of vertical drain-improved soft deposit consolidation considering smear zone, well resistance, and creep effects. Computers and Geotechnics”, 2020. https://doi.org/10.1016/j.compg o.2020.103602
Nicholson P, “Ground improvement techniques and applications”, In Soil Improvement and Ground Modification Methods, Ed. USA: Elsevier, 2015, 9-17. ISBN: 978-0-12-408076-8
Nicholson P, “What is ground improvement?,” In Soil Improvement and Ground Modification Methods, Ed. USA: Elsevier, 2015, 1-6, ISBN: 978-0-12-408076-8
PCA, “Soil-Cement Handbook”, Portland Cement Association, Skokie, USA, 1987.
Singh R, Bhunia P, “Understanding intricacies of clogging and its alleviation by introducing earthworms in soil biofilters”, Science of the Total Environment, 2018, 633, 145-156.
Suravi P, Kousik D, “Effect of clogging of stone column on drainage capacity during soil liquefaction, Soils and Foundations”, 2018, 1-12.
Suravi P, Kousik, D, “Effect of clogging of stone column on drainage capacity during soil liquefaction”, Soils and Foundations, 2018, 90-143.
Tai P, Zhou C, “Effects of Clogging on Settlement Predictions of Ground Improved with Stone Columns”, Korean Society of Civil Engineers, 2019. DOI 10.1007/s12205-019-2414-y
Vega J, Scheerer H, Andersohn H, Oechsner M, “Experimental studies of the effect of Ti interlayers on the corrosion resistance of TiN PVD coatings by using electrochemical methods”, Corrosion Science, 2018, 133 240-250. doi:10.1016/j.corsci.2018.01.010.
Weber TM, Plötze M, Laue J, Peschke G, Springman SM, “Smear zone identification and soil properties around stone columns constructed in-flight in centrifuge model tests”, Ge´otechnique, 2010, 60 (3), 197-206.
Yong CF, McCarthy DT, Deletic A, “Predicting physical clogging of porous and permeable pavements”, Journal of hydrology, 2013, 481, 48-55. http://dx.doi.org/10.1016/j.jhydrol.2012.12.009

فایل ها

هم رسانی

ارجاع به این مقاله

آمار