温度及含盐量对滨海路基填料力学特性的研究

Study of the influence of temperature and salt content on the mechanical properties of coastal road base filling materials

滨海路基填料服役性能,随温度及含盐量的改变而变化。目前,对于不同温度及含盐量下路基服役性能缺乏准确的认识。为此,对大三轴试验系统进行温控模块升级,采用循环流体加热模式,实现试样温度的精准控制。选取浙江省某路基采石场碎石填料进行饱和排水剪切试验,分析不同温度下低围压路基填料静力剪切特性。同时,考虑到滨海地区路基填料受海水入侵影响,填料受氯盐影响而盐渍化,因此,对不同含盐量的盐渍路基填料进行浸水试验。研究表明,温度升高,使密实路基填料表现出软化现象,其峰值强度随着温度升高而降低;路基填料围压越高,其峰值强度随温度的衰减越明显;残余强度基本不受温度变化影响;浸水前干燥及浸水后饱和两种条件下,土体强度表现出随含盐量的升高而升高的现象。浸水前后粗颗粒盐渍土剪切强度有着明显的降低,减弱程度随着含盐量的升高,表现出先迅速增大而后趋于平缓的现象。

The service performance of coastal roadbed filler varies with the change of temperature and salt content. At present, there is a lack of accurate understanding of the service performance of roadbeds at different temperatures and salt contents. For this reason, the temperature control module of the large triaxial test system is upgraded and the circulating fluid heating mode is adopted to achieve accurate control of the specimen temperature. A roadbed quarry gravel filler in Zhejiang Province was selected for saturated drainage shear test to analyze the static shear characteristics of low perimeter pressure roadbed filler under different temperatures. At the same time, considering that the roadbed filler in coastal areas is affected by seawater intrusion and the filler is salted by chlorine salt, therefore, the salted roadbed filler with different salt content is subjected to water immersion test, and the study shows that the temperature increases so that the dense roadbed filler shows softening phenomenon and its peak strength decreases with the increase of temperature;the higher the perimeter pressure of the roadbed filler, the more obvious the attenuation of its peak strength with temperature;residual strength largely unaffected by temperature changes;the residual strength is basically not affected by Under the conditions of dry before and saturated after water immersion, the strength of the soil exhibits the phenomenon of increasing with the increase of salt content. The shear strength of coarse-grained saline soils before and after immersion has a significant decrease, and the degree of weakening increases rapidly with the increase of salt content, and then tends to level off.