高填方土石混合料强度与变形特性及沉降预测研究

发布时间：2018-11-21 12:24

【摘要】：为解决高填方土石混合料强度与变形计算难题,对不同初始含水量不同初始干密度的土石混合试样进行剪切试验和压缩试验,深入分析不同土石比试样的强度与变形特性随初始参数的变化规律。结果包括:(1)初始压实度越小的试样侧限压缩应变越大,初始含水量越大的试样侧限压缩应变越大;压缩系数随竖向压力的增大整体先增大后减小,压缩模量随竖向压力的增大整体呈增大趋势;(2)类似高填方工程中填筑体初始压实度宜控制在0.93以上,初始含水量控制在最优含水量±(2%~3%),土石比控制为2∶8~4∶6;(3)粉质黏土和砂质泥岩混合料压实土的干密度与竖向压力之间呈幂函数关系,建立由填土层的初始状态和所受荷载预测填筑土层强度和沉降量的算法;(4)考虑初始状态的填方沉降预测方法是合理的,采用其略微偏大的变形计算结果进行高填方设计或施工,可使得高填方地基质量控制偏于安全;(5)最优含水量范围内不同压实系数引起的沉降差异较小;随着压实系数的增大,地基沉降变形明显减小;土石比为2∶8时压实度增大对地基沉降的影响程度大于土石比为4∶6的高填方地基。研究成果可用于土石混合料高填方地基变形分析与计算。
[Abstract]:In order to solve the problem of strength and deformation calculation of high fill earth-rock mixture, shear tests and compression tests were carried out on the soil-rock mixed samples with different initial moisture content and different initial dry density. The variation law of strength and deformation characteristics with initial parameters of different soil-rock ratio specimens is analyzed in depth. The results are as follows: (1) the smaller the initial compaction, the greater the lateral compression strain, and the greater the initial moisture content; The compression coefficient increases first and then decreases with the increase of vertical pressure, and the compression modulus increases with the increase of vertical pressure. (2) in similar high fill projects, the initial compaction should be controlled above 0.93, the initial water content should be controlled in the optimum water content 卤(2%), and the ratio of soil to rock should be controlled to 2: 8 8: 4: 6; (3) the relationship between dry density and vertical pressure of silty clay and sandy mudstone mixture is power function. (4) the method of settlement prediction considering initial condition is reasonable. The design or construction of high fill with slightly larger deformation calculation result can make the quality control of high fill foundation more safe. (5) the difference of settlement caused by different compaction coefficient is small in the range of optimal water content, and the settlement deformation of foundation decreases obviously with the increase of compaction coefficient. When the ratio of soil to rock is 2:8, the influence of compaction on the settlement of foundation is greater than that of high fill foundation with the ratio of soil to rock at 4:6. The research results can be used to analyze and calculate the deformation of soil and rock mixture high fill foundation.
【作者单位】：兰州理工大学土木工程学院;兰州理工大学西部土木工程防灾减灾教育部工程研究中心;
【基金】：甘肃省科技重大专项计划项目(1302FKDA030) 教育部长江学者和创新团队支持计划项目(IRT13068)~~
【分类号】：TU43

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