Stability of any structure depends on strength properties of underground soil on which it is constructed. Structures basically transfer all the loads comes on itself directly to the ground. If the underlying soil is not stable enough to support transferred loads then various types of failure occur such as settlement of the structure, cracks and so on. To solve this issue, soil improvement is necessary because it not only lowers the construction cost but also cuts the risk of any damage of structure later on. Numerous improvement methods can be adopted to make ordinary soil stable enough to support the structural loads. In this research work a number of tests were conducted using both ordinary soil and fiber reinforced soil. Soil samples for unsoaked and soaked CBR tests were prepared at its maximum dry density analogous to its optimum moisture content in the CBR mould with and without fiber. The reinforcing agent used in this study are natural bamboo fibers having diameter of 3 and 6 mm and length of 10 and 20 mm respectively. The proportion of bamboo fiber by waterless weight of normal soil was used as 0.20, 0.40, 0.60, 0.80, 1.00, 1.20 and 1.40%. Bamboo fiber is natural fiber, acts as a strengthening material for ordinary soil. It binds the soil particles together and helps in reduction of rapid change in volumetric properties. Addition of fiber improves the ductility behavior and increases the CBR value of ordinary soil. It was observed from the test results that unsoaked and soaked CBR value of soil increases with the increase in length and diameter of bamboo fiber. It was also found that increasing the percentage of bamboo fiber increases the CBR value of reinforced soil, and this increment is significant at fiber dosage of 1.2%. This significant increase of CBR value will diminish the thickness of pavement.

中文翻译：

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普通土壤中竹纤维的随机掺入及其影响CBR值的研究

任何结构的稳定性都取决于构造该结构的地下土壤的强度特性。结构基本上将所有载荷直接转移到地面上。如果下面的土壤不够稳定，无法支撑传递的载荷，则会发生各种类型的破坏，例如结构沉降，裂缝等。为了解决这个问题，土壤改良是必要的，因为它不仅降低了建筑成本，而且降低了以后破坏结构的风险。可以采用多种改进方法使普通土壤足够稳定以支撑结构载荷。在这项研究工作中，使用普通土壤和纤维增强土壤进行了许多测试。将未浸湿和浸湿的CBR试验的土壤样品制备成其最大干密度类似于其在有纤维和无纤维的CBR模具中的最佳水分含量。本研究中使用的增强剂是天然竹纤维，其直径分别为3和6 mm，长度分别为10和20 mm。竹纤维在正常土壤中的无水重量比例为0.20％，0.40％，0.60％，0.80％，1.00％，1.20％和1.40％。竹纤维是天然纤维，可作为普通土壤的增强材料。它将土壤颗粒粘合在一起，有助于减少体积特性的快速变化。纤维的添加改善了延展性并增加了普通土壤的CBR值。从试验结果可以看出，未浸透和浸透的土壤CBR值随竹纤维长度和直径的增加而增加。还发现增加竹纤维的百分比会增加加筋土壤的CBR值，这种增加在纤维用量为1.2％时很明显。CBR值的显着增加将减小路面的厚度。