以广西南宁膨胀土为研究对象,考虑气象因素的影响,进行了现场膨胀力测试。测试场地设置桩和框锚结构,在土体中沿水平方向和垂直方向设置土压力盒,测试浅层土体水平向和竖向膨胀力,膨胀力的测试经历了一个完整的雨季。测试结果表明,土体膨胀力的变化与降雨入渗息息相关,"旱涝急转"的过程会造成土体膨胀力骤然变化,但雨季的持续又会对土体水平向和竖向膨胀力带来不同影响。现场对膨胀土竖向和水平向膨胀力的测试结果可为工程设计的优化提供参考。
Considering the influence of atmosphere action, field test of swelling force on expansive soil is carried out in Nanning, Guangxi. Pile and frame anchor structure are set up. Earth pressure cells are installed along the vertical and horizontal direction to measure the shallow swelling pressure. The test lasts a whole rainy season. The testing results show that swelling force is closely linked to the process of rainfall. The phenomenon, which long drought turns the rain, induces a sudden change of swelling force. But the persistence of rainfall brings different influence on vertical and horizontal swelling force. The results of field test can provide reference to optimize the engineering design.