改良盐渍土物理力学性质试验研究

Experimental Study on the Physical and Mechanical Property of Improved Saline Soil

盐渍土作为一种性质特殊的土体,在用作路基填料时表现出易溶陷、盐胀、腐蚀等问题。结合某铁路工程建设,采用石灰、水泥及粉煤灰对盐渍土进行改良试验研究,分析了石灰、水泥及粉煤灰掺量对改良盐渍土的击实特性及无侧限抗压强度的影响关系。结果表明:改良盐渍土的最优含水率随改良材料掺量的增加而增大;除水泥改良土的最大干密度随改良材料的增加而增大外,石灰、石灰粉煤灰、石灰水泥改良土的最大干密度均随改良材料掺量的增加而减小。改良盐渍土的无侧限抗压强度与龄期呈正相关关系。龄期一定时,因部分石灰水化和物理作用的不完全致使石灰、石灰粉煤灰及石灰水泥改良盐渍土的无侧限抗压强度随改良材料掺量的增加呈先增大后减小的变化趋势,而水泥改良盐渍土的无侧限抗压强度则随改良材料掺量的增加而增大。

As a special soil mass, the saline soil presents such problems as easy to dissolve and sink, salt expansion, and corrosion, etc. when it is used as roadbed filling. Based on the construction of a railway and the experimental study on the improvement of saline soil using lime, cement and coal ash, the influence of the content of lime, cement and coal ash to the compaction characteristics and unconfined compressive strength of the improved saline soil is analyzed. The results show that the optimum moisture content of the improved saline soil is increased with the increase of the content of improved materials. Except the cement improved soil, the maximum dry density of the lime, lime coal ash and lime cement improved soil is decreased with the increase of the content of improved materials. The unconfined compressive strength and age of the improved saline soil have positive correlation. When the age is constant, the unconfined compressive strength of the lime, lime coal ash and lime cement improved saline soil presents the variation trend of first increase and then decrease with the increase of the content of improved materials due to the incompleteness of hydration and physical action of partial lime, but the unconfined compressive strength of cement improved saline soil is increased with the increase of the content of improved materials.