نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی کارشناسیارشد عمران و بهرهبرداری جنگل، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
2 دانشیار، گروه جنگلداری، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
3 استادیار، گروه جنگلداری، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
4 کارشناس محقق، بخش تحقیقات جنگل، مؤسسه تحقیقات جنگلها و مراتع کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Forest road bed soils often have problems such as high clay content, low load-bearing capacity and shear strength, difficulty in compaction, and the possibility of subsidence.
Therefore, stabilizing and improving soil strength using additives has always been of interest to researchers and road engineers. On the other hand, today, the use of waste materials in soil stabilization has become common due to its economic benefits.
Methodology: The study area is located in Dr. Bahramnia Educational-Research Forest Series 1. In this study, first, 5 thrust points containing fine-grained and swelling soil were prepared, and at least 3 samples from each were prepared by simple random method, each sample weighing 50 kg. In order to compare the efficiency of additives, soil samples were mixed with different amounts of 0, 1, 3, 5, 10, 15, and 20 percent of straw and stubble, lime, and cement. Geotechnical properties, including compaction properties, Atterberg limits, and compressive strength or CBR, were investigated in all samples. The investigation of compaction properties, including maximum dry soil density and optimum moisture content, was carried out by Proctor test, Atterberg limits including flow limit, plastic limit, and related indices by Casagrande and plastic wick methods, and compressive strength or CBR was carried out by California loading test.
Results: The results of comparing the average loading capacity of treated soil samples showed that the loading capacity increased significantly with the addition of lime, cement and straw. In addition, the plasticity index decreased significantly with the addition of more cement, lime and straw to the soil.
The lowest plasticity index was achieved with the addition of 20% cement. In general, straw treatment had no significant effect on improving the plasticity index of the soil compared to the control, and the plasticity index in this treatment was significantly higher than in soil samples treated with lime and cement. The soil loading capacity in samples treated with cement was significantly higher than in other treatments.
Conclusion: The results of this study showed that biological and non-biological additives have a significant effect on the mechanical strength of forest road bed soil, and these additives can play a significant role in increasing the loading capacity and reducing the clay index of the forest road. With proper management and use of these bioengineering techniques, it is possible to reduce the cost of forest road maintenance and increase the period of operation.
Keywords: Bioengineering, Biological and non-biological Additives, CBR , Forest Road, Plasticity Index,.
کلیدواژهها [English]