بررسی رفتار برشی ستون‌های سنگی محصور شده با ژئوسنتتیک‌ در بستر ماسه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان

• عادل شکیبی نژاد ¹
• سجاد قلی پور ²
• مسعود مکارچیان ³

¹ دانشکده مهندسی، دانشگاه بوعلی‌سینا، همدان

² گروه مهندسی عمران، دانشکده فنی و مهندسی خوی، دانشگاه صنعتی ارومیه، ارومیه.

³ دانشکده مهندسی، دانشگاه بوعلی‌سینا، همدان.

10.22067/jfcei.2024.90055.1323

چکیده

یکی از روش‌های بهسازی خاک‌های سست، استفاده از ستون‌های سنگی است که باعث کاهش نشست، افزایش مقاومت در برابر روانگرایی، بهبود ظرفیت باربری، تسریع زهکشی قائم و افزایش سرعت تحکیم می‌شود. در این مقاله تاثیر محصورکننده‌های ژئوتکستایل بر روی پارامترهای باربری جانبی ماسه سست مسلح شده با ستون سنگی مورد بررسی قرار گرفته است. به ‌همین منظور توسط دستگاه برش مستقیم بزرگ‌مقیاس، ستون‌های سنگی در حالت‌های غیرمسلح و مسلح شده با ژئوتکستایل مدل شده و تحت تنش‌های نرمال مختلف بهصورت تکی و گروهی با قطرهای متفاوت مورد آزمایش قرار گرفتد. نتایج بیانگر افزایش مقادیر مقاومت و پارامترهای برشی ماسه سست از طریق مسلح نمودن ستون‌های سنگی است؛ به‌طوری ‌که استفاده از ستون سنگی غیرمسلح در بستر ماسه سست با سطح مقطع تا 17% سطح ماسه، باعث افزایش حدود 12% در زاویه اصطکاک داخلی ماسه و 70% در مقاومت برشی حداکثر شده است. همچنین استفاده همزمان از ستون سنگی و ژئوتکستایل موجب بهبود جزئی حدود 3% در میزان زاویه اصطکاک داخلی و تا حدود 60% در مقدار چسبندگی و 2/2 برابر در مقاومت برشی گردیده است.

کلیدواژه‌ها

• ستون سنگی
• بهسازی خاک
• ژئوتکستایل
• برش مستقیم بزرگ مقیاس

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عنوان مقاله [English]

Investigation of Shear Behavior of Stone Columns in Sandy Bed

نویسندگان [English]

• Adel Shakibi Nezhad ¹
• sajjad gholipour ²
• masoud makarchian ³

¹ Civil Engineering Department, Bu-Ali Sina University, Hamedan

² Department of Civil Engineering, Engineering Faculty of Khoy, Urmia University of Technology.

³ Civil Engineering Department, Bu-Ali Sina University.

چکیده [English]

There are various methods to improve loose soils. One of the improvement methods is the use of stone columns. This method decrease settlement, increase the resistance to liquefaction, improve load bearing capacity, vertical drainage and increase the speed of consolidation. In this paper, the effect of geotextile enclosures on the lateral bearing capacity of loose soil reinforced by stone columns are investigated. In order to study the behavior of stone columns, large-Scale Direct shear apparatus was used. The stone columns modeled in this apparatus have been tested in unreinforced and reinforced with geotextile materials under different normal stresses and in single and group mode with different diameters. The results show an increase in the value of the shear parameters of loose sand by reinforcing stone columns, so that the use of unreinforced stone column in the loose sand bed up to 17% of the sand surface increases the internal friction angle of the sand by 12% and 70% in the maximum shear strength, and the simultaneous use of the stone column and geotextile have led to a slight improvement of about 3% of the internal friction angle, and up to about 60% adhesion and 2.2 times the shear resistance depending on different parameters.

کلیدواژه‌ها [English]

• Stone Column
• Soil Improvement
• Geotextile
• large Scale Direct shear

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