天然椰壳纤维加固红黏土地基模型试验

由于造价低、抗震性能好、施工简便等优点，加筋法成为一种常见的地基加固方法，天然环保的加筋材料选取是地基加固方法面临的难题之一。采用天然椰壳纤维对红黏土地基进行加固，通过载荷试验研究椰壳纤维加筋深度对红黏土地基承载变形能力的影响，并分析了土压力沿深度的分布规律。结果表明:随着加筋深度的增加，承载比均有较为明显的增大，但随着沉降量与基础宽度的比值从0.1增加到0.6，承载比大体上表现为先减小后稳定的趋势，且加筋深度越大，减小的幅度也越大。加筋深度为2 cm时，不同深度处的土压力均明显小于所施加荷载。加筋深度为4 cm时，埋深5 cm处土压力/荷载稳定在约0.6，其他深度处的土压力/荷载在荷载/最大荷载达到0.3时趋于稳定。加筋深度为6 cm时，埋深5 cm处土压力与荷载基本接近，其他深度处的土压力/荷载基本稳定，但均明显小于施加的荷载。由于应力集中，靠近加筋范围或在加筋范围内的土压力与所施加的荷载大小接近，远离加筋范围的土压力明显减小，当土压力计埋置深度达到2倍基础宽度左右时，土压力/荷载基本不变，说明荷载主要影响范围约为基础宽度的2倍。研究成果为地基加固的材料选择和海南地区地基加固提供参考。 

Model tests on the red clay foundation reinforced by the natural coir fiber

Due to the advantages of low cost, good seismic performance, simple construction, etc., reinforcement method has become a common method of foundation improvement. However, the geosynthetic used in the reinforcement method is not natural and environmentally friendly. To solve this problem, the natural coir fiber is used to reinforce the red clay foundation in this paper. The effect of the coir fiber reinforcement depth on the deformation and bearing capacity of the red clay foundation is studied through load tests. The distribution law of the earth pressure along depth is analyzed. The results show that the load bearing ratio increases significantly with the increasing reinforcement depth, but as the settlement to the foundation width ratio increases from 0.1 to 0.6, the load bearing ratio generally shows a trend of decreasing and then stabilizing, and the greater the depth of reinforcement, the larger of the reduction ratio. When the reinforcement depth is 2 cm, the earth pressures at different depths are significantly less than the applied loading. When the reinforcement depth is 4 cm, the earth pressure to the loading ratio at 5 cm is stable at about 0.6, and the earth pressure to the loading ratio at other depths tends to be stable when the loading to the maximum loading ratio reaches 0.3. When the reinforcement depth is 6 cm, the earth pressure at 5 cm is basically close to the loading, and the earth pressure to the loading ratio at other depths is basically stable, but they are all significantly smaller than the applied loading. Due to stress concentration, the earth pressure near or within the reinforcement range is close to the applied loading, and the earth pressure away from the reinforcement range is significantly reduced. When the buried depth of the earth pressure cell reaches about 2 times of the foundation width, the earth pressure to the load ratio is basically unchanged, indicating that the main influence depth of the loading is about 2 times of the foundation width. The conclusions can provide a certain reference for similar engineering.