天然砂砾改良膨胀土胀缩变形试验及相关模型预估

Experimental Study on Swelling Shrinkage Characteristics of Natural Gravel Improving Expansive Soil and Forecast of Relative Model

以某市机场路改建工程k0+970处膨胀土为研究对象,通过掺入沿线K0+150处的天然砂砾对其进行物理改良。开展了重型击实试验、自由膨胀率试验、无荷膨胀率试验、有荷膨胀率试验、膨胀力试验和收缩试验,探讨不同天然砂砾掺量下,改良土体胀缩特性的变化规律和改良的可行性,并建立了相应的数值预估模型。通过补充不同配合比试验,验证了预估数值模型的正确性。

Expansive soil of k0 ＋ 970 segments in municipal airport road is studied. Physical improvements for expansive soil are made by the incorporation of natural gravel soil along the KO ＋ 150 segments. A series of tests are carried out, which include heavy compac- tion test, free expansion ratio test, non-loaded swelling ratio test, linear swelling ratio test, the expansion force test and shrinking test. The swelling-shrinkage characteristics and feasibility of expansive soil mixed with a different proportion of natural gravel are studied. The appropriate numerical prediction model is established. The correctness and accuracy of the numerical model are testified by addi- tional testing.