مطالعه آزمایشگاهی ظرفیت باربری معادل بستر رسی بهسازی شده با ستون سنگی

نوع مقاله : مقاله پژوهشی

نویسندگان

کریم بهاری امینه ¹

سید محمد علی صدرالدینی ²

محمد هادی علیزاده الیزیی ³

¹ گروه مهندسی عمران، واحد رودهن، دانشگاه آزاد اسلامی ، رودهن، ایران.

² گروه مهندسی عمران ، واحد اسلامشهر ، دانشگاه آزاد اسلامی ، اسلامشهر ، ایران.

³ گروه مهندسی عمران ، واحد رودهن ، دانشگاه آزاد اسلامی ، رودهن ، ایران.

10.22067/jfcei.2025.92285.1346

چکیده

در چند دهه‌ی اخیر، ساخت‌وساز بر روی خاک‌های سُست و مسئله‌دار، چالش‌ها و مشکلات زیادی را پیش‌روی مهندسان ژئوتکنیک قرار داده است. در این میان، روش‌های متعددی برای بهسازی این خاک‌ها مورد استفاده قرار گرفته است. از جمله‌ی این روش‌ها، استفاده از ستون سنگی است که با حذف بخشی از خاک ضعیف و جایگزینی آن با ستون‌های خاک دانه‌ای صورت می‌گیرد. در این تحقیق، بهسازی بستر رسی سست از دو طبقه‌ی CL و CH، با ستون‌های سنگی مورد بررسی قرار گرفته است. بدین‌منظور، نمونه‌های بهسازی نشده و بهسازی شده با گروه ستون سنگی، شامل 7 ستون با قطر 30 میلیمتر و چیدمان مثلثی، در دستگاه برش مستقیم بزرگ‌مقیاس مورد آزمایش قرار گرفته و پارامترهای مقاومت برشی معادل و مقادیر ظرفیت باربری تعیین شده‌اند. آزمایش برش با استفاده از روش سریع انجام شده است. همچنین، تأثیر متغیرهایی چون نوع خاک پیرامونی، تعداد لایه‌های ساخت ستون سنگی و راستای چینش ستون‌های سنگی محدود با چیدمان مثلثی (رأس/ قاعده)، بر پارامترهای مقاومت برشی و ظرفیت باربری مورد ارزیابی قرار گرفته است. بر اساس نتایج حاصل، بهسازی خاک رسی با استفاده از روش گروه ستون سنگی موجب افزایش قابل توجه ظرفیت باربری خاک‌های سست شده است. نتایج آزمایش انجام شده نشان داد کیفیت ستون سنگی اهمیت زیادی در توان باربری آن دارد. علاوه بر این بهسازی خاک رسی CL نسبت به بهسازی خاک CH به روش ستون سنگی می‌تواند توان باربری بستر را بیشتر افزایش دهد که بیانگر کارایی بیشتر این روش بهسازی در خاک های رسی سخت تر است.

کلیدواژه‌ها

بستر رسی

ستون سنگی

برش مستقیم بزرگ‎مقیاس

مقاومت برشی

ظرفیت باربری

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عنوان مقاله English

Laboratory Assessment of the Equivalent Bearing Capacity of Clay Bed Improved with Stone Columns

نویسندگان English

Karim Bahari ¹

Sadreddini Seyyed Mohammad Ali ²

Mohammad Hadi Alizadeh elizei ³

¹ Department of Civil Engineering, Ro.C., Islamic Azad University, Roudenen, Iran.

² Department of Civil Engineering,Ir. C., Islamic Azad University , Eslamshahr, Iran.

³ Department of Civil Engineering, Ro. C., Islamic Azad University, Roudenen, Iran

چکیده English

Over the past few decades, construction on loose and problematic soils has posed significant challenges for geotechnical engineers. Among the methods to improve these soils, stone columns are notable, involving the replacement of weak soil portions with granular columns. This research investigates the enhancement of loose clay beds of classes CL and CH using sand columns.Unreinforced soil samples and those improved with a group of seven stone columns (30 mm diameter, arranged in a triangular pattern) were tested using a large-scale direct shear apparatus. Equivalent shear strength parameters were determined, and bearing capacity values were calculated. The shear tests employed the Fast method.

The effects of variables such as the type of surrounding soil, the number of layers in stone column construction, and the orientation of the limited stone columns (apex/base in triangular arrangement) on shear strength parameters and bearing capacity were evaluated. Results indicated that improving clay soils with stone columns significantly increased the bearing capacity of loose soils. The experimental findings showed that the execution method of stone columns greatly influences their load-bearing capacity. Moreover, improving CL clay soil with stone columns enhanced the bearing capacity more effectively than CH clay soil, indicating higher efficiency of this method in stiffer clay soils.

کلیدواژه‌ها English

Clayey bed

Sand column

Large-scale direct shear Test

Shear strength parameters

Bearing capacity

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