摘要
作为路基填料的红黏土,掺入天然砂砾改良后其力学指标会发生相应的变化。为了探究这种变化趋势,在红黏土中掺入10%,20%,30%,40%,50%的天然砂砾,分别进行CBR值、回弹模量值、无侧限抗压强度值、抗剪强度指标试验。试验结果表明,掺砂能显著改善红黏土的水理特性和力学性能;随着掺砂比例的增加,CBR值、回弹模量值均增大;无侧限抗压强度值随着掺砂量的增加,先逐渐增大后逐渐减小,当掺砂量达到30%时,无侧限抗压强度达到最大;黏聚力随着掺砂比例的增加而减小,内摩擦角随着掺砂比例的增加而增大,抗剪强度随着掺砂比例的增加先增大后减小,当掺砂比例达到30%时,抗剪强度达到最大值。在此基础上,对各力学指标与掺砂量之间的关系进行了曲线拟合,建立起了数学模型。最后,在红黏土中掺入5%,15%,25%,35%,45%的天然砂砾,补充各力学指标试验,将试验值与理论计算值进行比较。结果表明,力学指标模型计算值与试验实测值吻合较好,相对误差大多控制在5%以内,建立的数学模型具有较好的适应性。
The mechanical index of red clay as roadbed filler changes when it is improved by adding natural gravel. In order to explore this trend, the CBR, modulus of resilience, unconfined compression strength and shear strength are tested after blending different contents （ 10% , 20% , 30% , 40% , 50% ） of natural gravel soil in red clay. The result shows that （ 1 ） the water physical property and mechanical property of red clay are improved obviously; （2） The CBR and modulus of resilience increase as the content of gravel soil goes up; （3） the unconfined compression strength shows a trend of first increases and then decreases as the content of gravel soil goes up, the unconfined compression strength reaches maximum when the gravel content is 30% ; （4） cohesive force decreases with the increasing of sand proportion, the inner friction angle increases along with the gravel soil content growth, shear strength first increases and then decreases with the increasing of sand proportion, and the shear strength reaches the maximum when the sand proportion reaches 30%. Based on these data, the relationship curves of mechanical indexes with the content of gravel soil are fitted, and the mathematical model is created. At last, the supplementary test values and theoretical values of mechanical index are compared after adding natural gravel soil into red clay with the contents of 5% , 15% , 25%, 35%, 45% respectively. The result shows that the model calculation values of mathematical indexes are consistent with the test values, the relative error is within 5%, the established mathematical model has good adaptability.
出处
《公路交通科技》
CAS
CSCD
北大核心
2015年第9期41-48,共8页
Journal of Highway and Transportation Research and Development
基金
湖北省公路管理局2013年自然科学研究项目
关键词
道路工程
路基填料改良
试验-模型预估
力学指标
红黏土
road projects
roadbed filler improvement
test-model predictive
mechanical index
red clay
