اندازه‌گیری ظرفیت باربری جاده جنگلی تازه روسازی شده به‌‌روش صحرایی با استفاده از نفوذسنج دینامیک (DCP)

نوع مقاله : علمی- پژوهشی

نویسندگان

1 استادیار، گروه جنگل‌داری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران

2 کارشناس مسئول گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران

3 کارشناس جنگل آموزشی و پژوهشی خیرود، دانشکده منابع طبیعی، دانشگاه تهران

چکیده

جاده‌های جنگلی با وجود هزینه‌بر بودن، به‌عنوان عاملی ضروری برای دسترسی به‌‌منظور مدیریت منابع جنگلی مطرح هستند. کیفیت این جاده‌ها تا حدود زیادی به نوع مصالح به‌ویژه در روسازی بستگی دارد که گاهی تا 70 درصد هزینه کل را دربر‌می‌‌گیرد. هدف از این مطالعه بکار بردن ابزار نفوذ‌سنج دینامیک (DCP) به‌‌منظور کنترل و بررسی مقدار ظرفیت باربری کالیفرنیا (CBR) در جاده تازه تکمیل شده با استفاده از تثبیت‌‌‌کننده یونی در بخش نم‌خانه جنگل خیرود بود. به این‌‌منظور با استفاده از DCP اقدام به برآورد ظرفیت باربری در رابطه با عمق در 28 نمونه و با پنترومتر مقاومت به نفوذ سطح جاده در محور وسط و کناره‌‌ها گردید. سپس مقادیر ایندکس نفوذ حاصل از DCP تبدیل به مقادیر CBR گردید. نتایج نشان داد که با‌ وجود استفاده از تثبیت‌‌کننده، مقاومت قسمت‌‌های با مصالح رس و مخلوط درشت‌‌دانه بیشتر از قسمت دارای خاک رس می‌‌باشد. همچنین بین مقادیر دو ابزار در لایه سطحی همبستگی مثبت و معنی‌داری وجود دارد. به‌طوری که ‌مقادیر CBR جاده کمتر از حد انتظار و ناکافی برای عبور ترافیک و در کلاسه ضعیف از نظر ترافیک‌‌پذیری قرار داشت. با توجه به عدم انجام آزمایش CBR در پروژه جاده‌های جنگلی به دلیل زمان و هزینه‌‌بر بودن، استفاده از DCP به عنوان ابزاری ساده، کارا، کم هزینه و بدون تخریب برای برآورد CBR عرصه توصیه می‌‌‌‌‌‌‌‌گردد.

کلیدواژه‌ها

عنوان مقاله [English]

Measuring the in situ California Bearing Ratio of a new constructed forest road using DCP

نویسندگان [English]

  • Ehsan Abdi 1
  • Hamid Soofi Mariv 2
  • Jafar Fathi 3
1 Assistant Professor, Department of Forestry and Forest Economics, Faculty of Natural resources, University of Tehran
2 Expert, Department of Forestry and Forest Economics, Faculty of Natural resources, University of Tehran
3 . Expert, Kheyrudkenar Educational and Research Forest, Department of Forestry and Forest Economics, Faculty of Natural Resources, University of Tehran
چکیده [English]

Despite the cost of forest roads, they are essential infrastructure to provide access for resource management. The quality of roads pavement depends largely on the material used, particularly type of pavement that sometimes includes up to 70% of total cost. The purpose of this study was to use the DCP for CBR assessment of a newly completed road segment. Therefore, a DCP and a penetrometer were used to assess penetration resistance. Then penetration index of DCP was converted to field CBR. The results showed that bearing ratio of sections with clay material (which treated with Ionic stabilizer) was significantly lower than sections with clay and gravel material. There is a significant positive correlation between values of DCP and penetrometer. CBR values of the investigated road were less than expected and improper for passing traffic, which road destruction and wheel rut caused by traffic pass at the end of summer, confirms the achieved result. Regarding the lack of CBR tests in forest road projects due to its cost-time consuming and road surface destruction, using DCP as a simple, efficient and non destructive tool is suggested for estimating field CBR.

کلیدواژه‌ها [English]

  • forest road
  • pavement
  • CBR
  • DCP
  • ionic stabilizer

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