تاثیر استفاده از محلول تبادل یونی CBR +4 در افزایش میزان باربری خاکهای رسی با شاخص خمیری مختلف

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده فنی و مهندسی، دانشگاه بین المللی امام خمینی )ره(، قزوین، ایران

چکیده

تاکنون در اکثر پروژ ههای اجرایی در ایران روش کار برای استفاده از ماده تثبی تکننده یونی CBR+4 ، انجام آزمایشهای تبادل یونی شیمیایی بوده است. ضرورت انجام این تحقیق بررسی مشخصات رفتار مقاومتی نمون ههای خاک رسی با PI مختلف تثبیت شده به این روش با انجام آزمایشهای مکانیکی از جمله CBR+4 است. همچنین عملکرد نمونه های تثبیت شده خاک با محلول تبادل یونی CBR+4 در سیکلهای تر و خشک شدن و ذوب-انجماد نیز برای اولین بار در این تحقیق مورد مطالعه قرار گرفته است. در تثبیت خاک با محلول CBR+4 ابتدا با توجه به میزان تبادل یونی خا کها که بوسیله یک آزمایش شیمیایی انجام م یشود، میزان مورد نیاز مواد تثبی تکننده تعیین م یشود. سپس، نمون هها در درصد رطوبت بهینه و بیشترین چگالی خشک ساخته شده و پس از عم لآوری به مدت دو هفته، نمونه های خشک مورد آزمایش قرار گرفتند. همچنین نمونه های خاک پس از دو هفته عمل آوری در شرایط خیس خورده نیز مورد آزمایش قرار گرفت هاند. نمون ههای خیس خورده در مقایسه با نمونه های خشک افزایش مقاومت بیشتری نشان دادند. سپس نمون هها تحت 1 تا 4 سیکل انجماد-ذوب و خشک-تر قرار گرفت هاند. نتایج نشان میدهند استفاده از محلول CBR+4 ، باربری خاکهای رسی را افزایش میدهد این افزایش در خاک با PI کمتر، بیشتر است. اگرچه سیکلهای انجماد-ذوب و خشک-تر باربری خاک را کاهش میدهند، ولی مقاومت نمونه خاک رس تثبیت شده پس از اعمال سیکلهای مذکور به طور قابل توجهی بیش از نمونه های تثبیت نشده بوده و در حد قابل قبول است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Using Ion Exchange Solution in Increasing Bearing Capacity of Clayey Soils with Various Plasticity Index (PI)

نویسندگان [English]

  • R. Ziaie Moayed
  • Seyed M.H Khatami
  • F. Allahyari
Civil Engineering Department, Imam Khomeini International University, Qazvin, Iran
چکیده [English]

So far, at the most of executive project in Iran, using CBR+4 ion stabilizer solution is a chemical ion-exchange experiments. The necessity of present study is the investigation about the characteristics of strength behavior of clayey soils with various PI stabilized by this method. The performance of stabilized soil samples by“CBR+4” ion-exchange solution in wetting-drying and freeze-thaw cycles also been studied for the first time in this study. In soil stabilization with CBR+4 solution Firstly, according to the amount of soils ion exchange, which is determined by a laboratory chemical test, the required amount of the stabilizer is determined. Then, At the most of executive project in Iran, using Tetrabromomethane (CBR+4) ion stabilizer
solution is a chemical ion-exchange experiments. The necessity of present study is the investigation
about the characteristics of strength behavior of clayey soils with various plasticity index (PI) stabilized
by this method. The performance of stabilized soil samples by CBR+4 ion-exchange solution in wettingdrying
and freeze-thaw cycles also been studied for the first time in this study. Firstly, in soil stabilization
with CBR+4 solution the required amount of the stabilizer is determined, according to the amount of
soils ion exchange, which is determined by a laboratory chemical test. Then, the samples are built in
their optimum moisture content and maximum dry densities and after curing the samples for two weeks,
dry samples are tested. Soils samples are also tested in saturated condition after two weeks curing time.
Saturated samples showed more increase in strength compared to dry samples. Stabilized soil sample
are also tested under 1 to 4 freeze-thaw and wetting-drying cycles. Tests results showed that using
CBR+4 stabilizer increase bearing capacity of clayey soils. This increase is higher in soils with lower
PI. Although freeze-thaw and wetting-drying cycles reduce soils bearing capacity, their strength are
significantly more than the un-stabilized samples and is acceptable.

کلیدواژه‌ها [English]

  • Soil Stabilization Ion Exchange CBR+4 PI California Bearing Ratio Test (CBR)
  • Freeze-Thaw and Wetting- Drying Cycles
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