水稻土的先期固结压力测定与分析

    Measurement and analysis of precompression stress of soil in rice field

    • 摘要: 土壤先期固结压力的大小通常采用受周向约束柱状土样的快速单轴压缩测试方法获取,该值的确定不仅是土壤结构保护的基础参考,还为确定合理的作业机械轴重、农业机械的设计及其田间运用提供理论依据。该试验通过对江浦农场水稻土的实际测试,得到未受压实耕层土壤的先期固结压力范围为58.84~69.19 kPa,而用拖拉机碾压处理后的先期固结压力区间上升为69.15~100.1 kPa,表明拖拉机的碾压导致土壤先期固结压力的增加,即破坏了土壤的原始结构。目前的农业机械接地压力通常在70 kPa以上,而大田所测的土壤先期固结压力却在60 kPa左右,因此机械的使用必会造成土壤的压实及其结构的破坏。

       

      Abstract: Pre-consolidation pressure was usually measured by fast uni-axial compression test on confined cylindrical soil, the determination of which provided a basis reference for soil structure protection and a theoretical foundation for the correct selection of axial load, as well as the design and field application of agricultural machineries. A field experiment was conducted in Nanjing Jiangpu farm to measure the pre-consolidation pressure. Its value was 58.84- 69.19 kPa for undisturbed soil and 69.15-100.1 kPa for compacted soil with a tractor. The results showed that wheel rolling increased soil pre-consolidation pressure and thus destroyed soil structure. The currently used agricultural machineries usually have a contacting pressure of 70 kPa above, while the measured value was around 60 kPa. It is concluded that the application of these machineries will caused soil compaction and soil structure destruction.

       

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