برآورد تاثیر شدت سربار بر پتانسیل رمبندگی خاک در الگوهای مختلف نفوذ آب

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه یزد، یزد، ایران

چکیده

خاک رمبنده در حالت خشک پایداری خوبی از خود نشان می‌دهد اما با ورود آب دچار نشست‌های قابل توجه می‌گردد. پارامترهای زیادی می‌توانند بر میزان نشست رمبندگی تاثیر بگذارند. میزان سربار در زمان خیس شدن یکی از مهمترین پارامترهای تاثیر گذار بر روی نشست و رفتار خاک رمبنده است. اشباع شدن خاک رمبنده از طریق منابع مختلفی مانند سیلاب، بارندگی، آبیاری، نشت لوله‌های مدفون و ... انجام می‌شود اما در آزمایش‌هایی که برای بررسی رفتار خاک رمبنده استفاده می‌شود، تاثیر این منابع قابل بررسی نیست. یک دستگاه با قابلیت شبیه‌سازی الگوهای مختلف نفوذ آب در خاک ساخته شد و با استفاده از سه سربار اشباع شدگی 100، 200 و 300 کیلوپاسکال تاثیر سربار در هر الگو نفوذ آب به صورت جداگانه مورد بررسی قرار گرفت. نتایج نشان می‌دهد که برای خاک رمبنده‌ استفاده شده، در هر سه سربار میزان پتانسیل رمبندگی آزمایش ادئومتر با آزمایش‌های الگوهای نفوذ آب اختلاف دارد و بیشترین اختلاف با مقدار 16 درصد مربوط به سربار 300 کیلوپاسکال است و در بین الگوهای مختلف نفوذ آب، الگوی نفوذ آب نقطه‌ای از بالا بیشترین پتانسیل رمبندگی را ایجاد می‌کند. تغییرات پتانسیل رمبندگی در مقابل تغییرات سربار اشباع شدگی نشان می‌دهد در تمام الگوهای نفوذ آب با افزایش سربار اشباع شدگی، پتانسیل رمبندگی کاهش می‌یابد اما میزان تغییرات برای هر الگو متفاوت است. به عنوان مثال با افزایش سربار از 100 تا 200 کیلوپاسکال، بیشترین کاهش پتانسیل رمبندگی با مقدار27/2 درصد در الگو نفوذ آب نقطه‌ای از پایین ایجاد می‌گردد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Evaluation of the effect of surcharge intensity on the collapse potential of soils in different water infiltration patterns

نویسندگان [English]

  • Javad Mahmoudi
  • reza pourhosseini
department of civil engineering, yazd university
چکیده [English]

Collapsible soils have good stability in dry states, but it experience significant settlements due to wetting. Many characteristics can affect the collapse settlement. The amount of wetting pressure is one of the most important parameters affecting the collapsible soil. Water can enter the collapsible soil from various sources such as floods, rainfall, irrigation, etc. However, in the tests used to investigate the behavior of the collapsible soils, the influence of these sources cannot be investigated. An apparatus capable of simulating different patterns of water infiltration in the soil was built and using three wetting pressures of 100, 200, and 300 kPa, the effect of surcharge in each pattern of water infiltration was investigated separately. The results show that if collapsible soil is used, in all three surcharges, the collapse potential of the oedometer test is different from the water infiltration tests. The biggest difference is related to the surcharge of 300 kPa that the maximum difference between the oedometer and water infiltration tests is 16%. When the water enters as top-point pattern, the highest collapse potential is created among the different patterns. The collapse potential decreases with the increase of the surcharge, but the amount of changes is different for each pattern. For example, with the increase of surcharge from 100 to 200 kPa, the greatest reduction of the collapse potential with a value of 27.2% is created in the bottom-point pattern.

کلیدواژه‌ها [English]

  • Collapse Potential
  • Water Infiltration
  • Apparatus
  • Surcharge
  • Collapsible Soil
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