辽西风积土路基土水特征曲线试验研究  

EXPERIMENTAL STUDY ON SOIL-WATER CHARACTERISTIC CURVE OF AEOLIAN SOIL ROADBED IN WESTERN LIAONING PROVINCE

作　　者：贾宝新 王荷[1] 周琳力 李志永 JIA Baoxin;WANG He;ZHOU Linli;LI Zhiyong(School of Civil Engineering,Liaoning Technical University,Fuxin1 23000;Institute of Geology,China Earthquake Administration,Beijing 100029)

机构地区：[1]辽宁工程技术大学土木工程学院,阜新123000 [2]中国地震局地质研究所,北京100029

出　　处：《工程地质学报》2018年第3期633-638,共6页Journal of Engineering Geology

摘　　要：基于土水特征曲线对工程性质的重要性,利用SDSWCC压力板仪和GDS饱和-非饱和应力路径三轴试验系统,详细研究了不同干密度、干湿循环次数和净平均应力对辽西风积土土水特征曲线的影响,并采用常用的3种模型,使用数学方法对所测数据进行拟合。试验结果表明,低基质吸力阶段,干密度、干湿循环和应力作用对风积土土水特征曲线影响显著:干密度更大时,土体内部孔隙率降低,饱和含水率降低,进气值升高,持水性能更好;干湿循环作用下,随着循环次数的增加,饱和含水率增高,失水速率变大,进气值降低,持水性能减弱,但3次干湿循环后趋于稳定;应力作用下土体发生收缩变形,密度变大,其产生的影响规律与干密度相似。高基质吸力阶段,三者的影响均很小。曲线拟合分析表明,Van Genuchten模型的拟合精度最高,能够更好地描述和预测辽西风积土的土水特征曲线。研究结果揭示了辽西风积土力学、工程性质与其它地域土体的一致规律,以及风积土自身独有的特性,为广泛开展的风积土路基、桥基等工程提供了判定风积土性质的参考和依据。The soil water characteristic curve（ SWCC） is an important engineering characteristic. This paper uses the SDSWCC pressure plate apparatus and GDS saturated-unsaturated stress path triaxial testing system to test the SWCC of arolian soil in western Liaoning Province. Also,detailed studies are carried out on the different dry density,dry-wet cycle and net mean stress for their influence on the SWCC of the aeolian soil. The usual three models use a mathematical method for fitting the measured data. The test results show that at the low matrix suction stage,the three factors of dry density,dry-wet cycle and stress have significant effects on the SWCC of aeolian soil.When the soil dry density is larger,the porosity in soil is lower,the saturated water content is lower,the air-entry value is bigger,water capacity is better. Under the action of dry and wet cycle,with the increase of the cycle times,the saturated water content is increased,the water loss rate becomes larger,the intake value is reduced,and the water holding performance is weakened. But after 3 times of the dry-wet cycle,it tends to be stable. Under the action of stress,there is shrinkage deformation of the soil. The density of soil becomes greater. The impact law issimilar to that of the dry density. In the high matrix suction stage,the influences of the three factors are small.Curve fitting analysis shows that Van Genuchten model has the highest fitting precision. It is better to describe and forecast SWCC of the aeolian soil in western Liaoning. The results reveal engineering and mechanical properties of the aeolian soil in western Liaoning have the same laws with soils in other regions. The results also reveal the unique features of aeolian soil. It can offer some reference and evidence to determine the aeolian soil properties. It is good for wide development of aeolian soil subgrade,bridge foundation engineering,and other projects.

关 键 词：风积土 土水特征曲线 干密度 干湿循环 应力状态 

分 类 号：TU42[建筑科学—岩土工程]