نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 استاد ، گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.
2 دانش آموخته کارشناسی ارشد علوم مهندسی جنگل، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.
3 استادیار، گروه جنگلداری، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.
4 دانش آموخته دکتری علوم مهندسی جنگل، دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract Background and objectives: In Hirkan forests, fine-grained clayey soils have created many problems in construction projects, especially road construction, due to their swelling, and have caused the instability of the road surface and as a result, the pavement has been damaged. Fine-grained soils are problematic due to unfavorable technical properties, especially plastic properties, low permeability, low strength, changes in pore water pressure, changes in volume, texture, chemical properties, and grain structure, and may present complex engineering problems for construction. One of the ways to improve the swelling characteristics of the soil is soil stabilization. Soil stabilization is the use of natural or synthetic additives to improve the mechanical properties of soil. Lime and plant waste are cheap, available and easy to use materials. Materials and methods: In this research, a fixed amount of three percent hydrated lime along with reed plant ash from Phragmites australis with a mixing ratio of three, six, nine and twelve percent to the road bed soil of the study area located in the educational and research forest of Sari University of Agricultural Sciences and Natural Resources - Darabkala was added and then soil mechanics tests including: Atterberg limit, standard compaction test, California bear ratio(CBR) test and uniaxial compressive strength(UCS) test were performed in three repetitions after the processing period. In this research, a constant amount of three percent hydrated lime along with reed ash with a mixing ratio of three, six, nine, and twelve percent was added to the road bed soil of the study area.
Results: The results show that the liquid limit and plasticity index decreased and placticity limit of the soil increased. The maximum dry weight of the samples decreased with the increase of reed ash, and the highest value of 14.52 KN/m3 was recorded and the lowest value of 11.97 KN/m3 was recorded in the soil sample with 3% lime and 12% reed ash. In CBR test, an increasing trend was recorded from 4.9% to 9.7% in the soil sample containing 3% lime and 12% reed ash. The result of the uniaxial compressive strength test in three time periods of 7, 14 and 28 days on the samples shows that the highest value of uniaxial compressive strength is 2.6 Kg/cm2 in the sample containing 3% lime and 6% reed ash after 28 days. Conclusion: Based on the findings of this research, it was concluded that reed ash can be used as a suitable pozzolanic material to stabilize the bed soil of the forest roads in the study area, and the ratio of three percent lime and six percent ash can be used for 28 days to stabilize the bed clay.
کلیدواژه‌ها [English]
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