石灰改良膨胀土击实样膨胀特性和力学性质试验研究

本文以宁淮高速公路淮安段膨胀土填料为研究对象,通过室内试验研究石灰改良膨胀土作为路基填料的膨胀性和力学性质。在天然膨胀土2%石灰砂化的基础上,制备不同初始含水率与压实度的石灰改良土,进行不同养护龄期的有荷膨胀率和强度特性试验。试验结果表明:石灰改良土线膨胀率和膨胀力均有大幅度的降低,且随含水率和养护龄期保持减小趋势、随压实度保持增大趋势;石灰改良土无侧限抗压强度、黏聚力、内摩擦角均有一定程度的提高。因此,石灰改良膨胀土作为路基填料的施工工艺在工程中是可行的,为膨胀土改良方案选择以及膨胀土地区公路路基设计和现场施工提供科学依据和参考。

Experimental Study on the Expansive and Strength of Expansive Soil Stabilized with Lime

Engineering properties of the Lime-improved expansive soil as highway foundation filling soils were studied here with the engineering background of Ninghuai Highway in Huai-An part. According to the 2% lime-improved natural expansive soil, swelling ratio and unconfined compressive test were carried out with different initial moisture content and the compacted ratio. The final results indicated that the value of line expansive ratio and expansive stress for lime improved soil both decreased greatly, which also suggested that both of the two values would keep decreasing with initial moisture content and curing age, but keep increasing with the compacted ratio. Moreover, the lime-improved expansive soil unconfined compressive strength, cohesion as well as the internal friction angle were all improved effectively. And so, it can be concluded that the lime-improved method for expansive soil is reasonable, and the new developed method is also helpful for road foundation design.