| 考虑固液二相互态特性的流固耦合模型 |
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| 引用本文： | 卢玉东,国金琦,程大伟,毛兴隆.考虑固液二相互态特性的流固耦合模型[J].中国公路学报,2023,36(1):58-69. |
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| 作者姓名： | 卢玉东 国金琦 程大伟 毛兴隆 |
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| 作者单位： | 1. 长安大学 水利与环境学院, 陕西 西安 710054;2. 长安大学 旱区地下水文与生态效应教育部重点实验室, 陕西 西安 710054 |
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| 基金项目： | 国家自然科学基金青年科学基金项目（41602237）；中央高校基本科研业务费专项资金项目（300102290106）；国家自然科学基金重点项目（41630634） |
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| 摘 要： | 为研究岩土体内的流固耦合作用对道路工程中道路建筑物/构筑物的变形和沉降，聚焦于构建考虑固液二相互态特性的流固耦合模型，首先构建以含水率为参数的固相物性参数方程（弹性模量、体积模量、极限偏应力）和以孔隙比为参数的液相物性参数方程（饱和含水率、残余含水率、Gardner模型参数），其次建立考虑固液二相互态影响的固相本构方程（邓肯-张模型）和液相本构方程（Gardner模型），之后将新构建的本构方程与固液二相控制方程联合使用构建出考虑固液二相互态特性影响的流固耦合模型。以非饱和黄土为研究对象，利用数值模拟软件构建考虑固液二相互态影响的非饱和土流固耦合数值模型，探索固液二相互态特性对非饱和土流固耦合影响机制。研究结果表明：随着含水率的增大，固相物性参数（弹性模量、体积模量、极限偏应力）均呈减小的趋势；含水率增大使得土体强度减小，表现为达到相同的应变，土体的应力减小；含水率增大，相同的变形情况下，土体所承受的荷载变小。随着孔隙比的增加，饱和含水率线性增加，残余含水率线性减小，Gardner模型参数β呈指数减小，土体内有效饱和度也随之增加；孔隙比增大还会导致土体饱和渗透能力的减小，非饱和相对渗透系数增加。在相同的载荷条件下，相较于未考虑互态影响的流固耦合模型，考虑互态影响的模型模拟的土体变形量较大，含水率、压力水头较小。
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| 关 键 词： | 道路工程 流固耦合模型 数值模拟 非饱和黄土 固液二相互态特性 |
| 收稿时间： | 2021-07-21 |
Fluid-solid Coupling Model Considering Solid-liquid Two-phase Interaction Characteristics |
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| LU Yu-dong,GUO Jin-qi,CHENG Da-wei,MAO Xing-long.Fluid-solid Coupling Model Considering Solid-liquid Two-phase Interaction Characteristics[J].China Journal of Highway and Transport,2023,36(1):58-69. |
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| Authors: | LU Yu-dong GUO Jin-qi CHENG Da-wei MAO Xing-long |
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| Affiliation: | 1. School of Water and Environment, Chang'an University, Xi'an 710054, Shaanxi, China;2. Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region of Ministry of Education, Xi'an 710054, Shaanxi, China |
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| Abstract: | This study focuses on the construction of fluid-solid coupling model considering solid-liquid two-phase interaction characteristics to study the deformation and settlement of road buildings/structures in road engineering caused by hydro-mechanical interactions in rock soil. First, the solid phase physical property parametric equation(Young's modulus, bulk modulus, and ultimate deviatoric stress) with moisture content as the parameter and liquid phase physical property parametric equation(saturated moisture content, residual moisture content, and parameters of the Gardner model) with the void ratio as the parameter are constructed. Second, the solid phase constitutive equation (Duncan-Zhang model) and liquid phase constitutive equation (Gardner model) are established considering the influence of the solid-liquid two-phase interaction, and the newly constructed constitutive equation and solid-liquid two-phase governing equation are combined to construct the fluid-solid coupling model that considers solid-liquid two-phase interaction characteristics. With unsaturated loess as the research object, using numerical simulation software to consider the influence of the solid-liquid two-phase interaction and a numerical model on the unsaturated soil, the influence mechanism of solid-liquid two-phase interaction characteristics on fluid-solid coupled in unsaturated soils was explored. The specific research results are as follows:with increasing moisture content, the solid phase physical property parameter tended to decrease; soil strength decreases as moisture content increases, and soil stress decreases when the strain is unchanged. As moisture content increases, the soil load decreases under the same deformation conditions. As the void ratio increases, the saturated moisture content increases linearly, and the residual moisture content decreases linearly. Parameter β in the Gardner model decreases exponentially, and the effective saturation in the soil increases accordingly. An increase in the void ratio also leads to the saturated hydraulic conductivity decreasing and unsaturated relative permeability coefficient increasing. Under the same loading conditions, compared with the fluid-solid coupling model without considering mutual effects, the model with mutual effects can simulate larger soil deformations, smaller moisture content, and pressure head. |
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| Keywords: | road engineering fluid-solid coupling model numerical simulation unsaturated loess solid-liquid two-phase interaction characteristics |
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