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研究了风化砂改良膨胀土对抗剪强度及其指标的影响。通过改变风化砂的掺量,研究了风化砂对膨胀土物理性质的影响。试验表明,随着掺砂比例的增加,最佳含水率逐渐下降,渗透系数逐渐增大,说明风化砂能有效降低膨胀土的塑性指数,增大膨胀土的透水性能,使之更适合用作公路路基填料。通过研究风化砂掺入比例及初始干密度对膨胀土抗剪强度指标c、φ值及抗剪强度的影响,可以得出:在掺砂比例一定时,改良膨胀土的粘聚力随着初始干密度的增大而增大,内摩擦角随着初始干密度的增大先增大后减小再增大,抗剪强度值总体逐渐增大;在初始干密度一定时,改良膨胀土的粘聚力随着掺砂比例的增大而减小,内摩擦角随着掺砂比例的增大先增大后减小,抗剪强度总体变化趋势减小。当初始干密度为2.0g/cm3,掺砂比例为30%时,抗剪强度达到最大值。
The effect of weathering sand on the shear strength and its index of expansive soil was studied. By changing the amount of weathered sand, we studied the effect of weathered sand on the physical properties of expansive soils. Experiments show that with the increase of sand content, the optimum moisture content decreases gradually and the permeability coefficient increases gradually, indicating that weathering sand can effectively reduce the plastic index of expansive soils and increase the water permeability of expansive so as to make it more suitable for Highway subgrade filler. By studying the effect of aerated sand incorporation ratio and initial dry density on shear strength indexes c and φ and shear strength of expansive soils, it can be concluded that the cohesion of modified expansive soils increases with the initial Dry density increases and the internal friction angle increases with the initial dry density increases first and then decreases and then increases, the overall shear strength value gradually increases; at a certain initial dry density, the improvement of expansive soil The cohesion decreases with the increase of sand content. The internal friction angle first increases and then decreases with the increase of sand content, and the overall trend of shear strength decreases. When the initial dry density of 2.0g / cm3, sand content of 30%, the shear strength reached its maximum.