基于Comsol Multiphysics的半浸泡非饱和水泥基材料水分输运数值模型研究
Numerical model of water transport in partially-immersed unsaturated cement-based materials using Comsol Multiphysics
张梦媛 1丁龙亭 1王选仓 2谢金生 2王孜健1
作者信息
- 1. 山东高速集团有限公司 创新研究院,济南 250000
- 2. 长安大学 公路学院,西安 710064
- 折叠
摘要
我国西部荒漠区盐渍土分布广泛,由可溶性硫酸盐导致的道路基层拱胀破坏已不容忽视.文中采用Comsol Multiphysics软件,基于多相流理论进行浸润状态下非饱和水泥稳定类混合料水分输运数值模拟研究,以毛细压力作为水相输运驱动力、以饱和蒸气压作为水气相传输驱动力推导了非饱和多孔介质内水相和湿空气相动力控制方程及蒸发控制方程,建立了考虑蒸发作用的半浸泡非饱和混合料水分输运模型.依据水分传输试验得到了3种不同级配类型水稳碎石混合料毛细吸收特性,验证了模型的准确性.结果表明,XM结构毛细吸收系数最大,为0.09 g/cm2;GK次之,为0.085 g/cm2;GM的毛细吸收系数最小;对于非饱和多孔介质来说,前期孔内流体的对流作用主要是由水分毛细传输引起的,后期由于蒸汽压差的存在孔隙内水气对流较为强烈;半浸泡下非饱和水稳基层混合料内部盐分的传输不能忽视水分毛细作用及水分蒸发引起的对流作用的影响.研究结果完善了非饱和介质水分传输理论,并为探究水-盐在非饱和水泥基材料内部的迁移传输及数值模型的建立提供了参考.
Abstract
Saline soils are widely distributed in the desert regions of western China,where road base deformation due to soluble sulfate poses a significant issue.Using multiphase flow theory,this study conducts a numerical simulation of water transport in unsaturated cement-based mixtures under infiltration conditions with Comsol Multiphysics software.The model considers capillary pressure as the driving force for water phase transport and saturated vapor pressure as the driver for both water and gas phase transport.Dynamic and evaporation governing equations for the water and wet air phases in unsaturated porous media are derived,forming the basis of a water transport model for partially-immersed unsaturated mixtures that accounts for water and wet air evaporation.Capillary absorption characteristics of three types of cement-stabilized materials are obtained through water transport testing,and model accuracy is verified against experimental results.Findings show that the capillary absorption coefficient is the highest for XM(0.09 g/cm2),followed by GK(0.085 g/cm2),and lowest for GM.In unsaturated porous media,fluid movement in pores is mainly driven by capillary water transport in the early stages,with later stages dominated by convective effects due to vapor pressure differences.These results highlight the critical influence of water capillary and evaporation on soluble salt transport in partially-immersed unsaturated cement-based mixtures.This research advances understanding of water transport in unsaturated media and provides a foundation for exploring water-salt transport in such materials and establishing numerical models.
关键词
土木工程/水泥基材料/非饱和介质/水分传输/数值模拟Key words
civil engineering/cement-based material/unsaturated porous media/water transport/numerical modeling引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据