اثر دما بر خصوصیات تورمی یک خاک متورم‌شونده در چرخه‌های خشک و تر

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشجو

2 دانشیار گروه مهندسی آبیاری و آبادانی دانشگاه تهران

3 مربی گروه مهندسی آبیاری و آبادانی دانشگاه تهران

چکیده

در این کار تحقیقاتی خواص مکانیکی یک خاک رسی متورم­شونده تحت تاثیر شرایط دمای ثابت و متغیر در چرخه­های خشک و تر متوالی مورد بررسی قرار گرفت. نمونه­های آزمایشگاهی با کیفیت­های مایع منفذی مختلف آب مقطر­، محلول سدیم­کلرید و کلسیم­کلرید ‌(با غلظت 250 گرم بر لیتر) به روش تراکم استاتیکی تهیه گردید. آزمایش­های چرخه­های­ خشک و تر روی نمونه­های ساخته شده در دو دستگاه تحکیم اصلاح ­شده تحت تاثیر سربار  ثابت 10  کیلوپاسکال انجام شد و درطول آزمایش تغییر شکل محوری اندازه­گیری گردید. در یکی از دستگاه­ها دما در چرخه­های خشک و تر متوالی مقدار ثابت 45 درجه سانتی­گراد و در دستگاه دیگر دمای چرخه­های خشک 45 درجه و دمای چرخه­های تر 25 درجه سانتی­گراد اعمال گردید. نتایج نشان داد در هر یک از حالات برای تمامی نمونه­ها پتانسیل تورمی تقریبا پس از طی 5 چرخه به تعادل می­رسد. هم­چنین مقایسه مقادیر پتانسیل تورمی نشان می­دهد که کاهش پتانسیل تورمی در حالت تعادل نسبت به چرخه­ای که بیشینه درصد تورم در آن اتفاق افتاده است برای نمونه ساخته شده با مایع منفذی مقطر در حالت دمای ثابت در مقایسه با نمونه­های ساخته شده با مایع منفذی سدیم­کلرید و کلسیم­کلرید به ترتیب به میزان  25/4 %  و 85/5 % بیشتر می­باشد هم­چنین در حالت دمای متغیر این کاهش به ترتیب 21/7 %  و 9/8 %  بیشتر می­باشد. علاوه بر این مقایسه نتایج در حالت دمای ثابت و متغیر نشان می­دهد که در حالت دمای ثابت پتانسیل تورمی نمونه‌­­ها با مایع منفذی سدیم­کلرید و کلسیم­کلرید در چرخه­های اولیه بیشتر از حالت دمای متغیر است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The effect of temperature on the behavior of an expansive soil during drying and wetting cycles

نویسندگان [English]

  • mohadeseh amini kelehroudi 1
  • Ali Raeesi Estabragh 2
  • jamal Abdolahi Baik 3
1 student
2 Associate Prof., Dept of irrigation and reclamation, univ of Tehran, Tehran, Iran
3 Lecturer., Dept of irrigation and reclamation, univ of Tehran, Tehran, Iran
چکیده [English]

In this research the mechanical behavior of an expansive soil (with different pore fluid) was investigated under the constant and variable temperature through experimental tests. The soil samples with different pore fluid (distilled water, NaCl and CaCl2 with concentration of 250 gr/Lit) were prepared by static compaction method. Experimental testes were conducted in two modified odometer under 10 KPa surcharge pressure at constant and variable temperature. The axial deformation of samples were determined during each test. The results showed that equilibrium condition is achieved nearly after 5 cycles. The reduction of swelling potential at equilibrium condition for sample with distilled water as pore fluid is more than samples with NaCl and CaCl2 solutions. In addition comparing the results for samples with NaCl and CaCl2 solution in variable and constant temperature indicated that reduction of swelling potential is not the same.

کلیدواژه‌ها [English]

  • swelling potential
  • constant and variable temperature
  • modified odometer
  • 10 KPa surcharge
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