Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method
The unsaturated seepage field coupled with heavy rainfall-induced surface flow mainly accounts for the slope instability. If the slope contains macropores, the coupled model and solution process significantly differ from the traditional one (without macropores). Most of the studies on the variation...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-12-01
|
| Series: | Water |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4441/13/24/3569 |
| _version_ | 1797499824972496896 |
|---|---|
| author | Shanghui Li Zhenliang Jiang Yun Que Xian Chen Hui Ding Yi Liu Yiqing Dai Bin Xue |
| author_facet | Shanghui Li Zhenliang Jiang Yun Que Xian Chen Hui Ding Yi Liu Yiqing Dai Bin Xue |
| author_sort | Shanghui Li |
| collection | DOAJ |
| description | The unsaturated seepage field coupled with heavy rainfall-induced surface flow mainly accounts for the slope instability. If the slope contains macropores, the coupled model and solution process significantly differ from the traditional one (without macropores). Most of the studies on the variation of the water field under the coupled effect of runoff and seepage on the slope did not consider the macropore structure. In this paper, two coupled Richards equations were used to describe the MF (Macropore Flow), and along with the kinematic wave equation, they were applied to establish a coupled model of SR (Slope Runoff) and MF. The numerical solving of the coupled model was realized by the COMSOL PDE finite element method, and an innovative laboratory test was conducted to verify the numerical results. The effects of different factors (i.e., rainfall intensity, rainfall duration, saturated conductivity, and slope roughness coefficient) on water content and ponding depth with and without macropores were compared and analyzed. The results show that infiltration is more likely to happen in MF than UF (Unsaturated Flow, without macropore). The depths of the saturation zone and the wetting front of MF are obviously greater than those of UF. When SR occurs, rainfall duration has the most significant influence on infiltration. When macropores are considered, the ponding depth is smaller at the beginning of rainfall, while the effects are not obvious in the later period. Rain intensity and roughness coefficient have significant influences on the ponding depth. Therefore, macropores should not be ignored in the analysis of the slope seepage field. |
| first_indexed | 2024-03-10T03:52:59Z |
| format | Article |
| id | doaj.art-33a16fb26dba4f478e310e6613e7b27c |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-10T03:52:59Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-33a16fb26dba4f478e310e6613e7b27c2023-11-23T11:01:09ZengMDPI AGWater2073-44412021-12-011324356910.3390/w13243569Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element MethodShanghui Li0Zhenliang Jiang1Yun Que2Xian Chen3Hui Ding4Yi Liu5Yiqing Dai6Bin Xue7College of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, ChinaDepartment of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350000, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350000, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350000, ChinaJiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Department of Mechanical Engineering, Southeast University, Nanjing 210096, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350000, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350000, ChinaThe unsaturated seepage field coupled with heavy rainfall-induced surface flow mainly accounts for the slope instability. If the slope contains macropores, the coupled model and solution process significantly differ from the traditional one (without macropores). Most of the studies on the variation of the water field under the coupled effect of runoff and seepage on the slope did not consider the macropore structure. In this paper, two coupled Richards equations were used to describe the MF (Macropore Flow), and along with the kinematic wave equation, they were applied to establish a coupled model of SR (Slope Runoff) and MF. The numerical solving of the coupled model was realized by the COMSOL PDE finite element method, and an innovative laboratory test was conducted to verify the numerical results. The effects of different factors (i.e., rainfall intensity, rainfall duration, saturated conductivity, and slope roughness coefficient) on water content and ponding depth with and without macropores were compared and analyzed. The results show that infiltration is more likely to happen in MF than UF (Unsaturated Flow, without macropore). The depths of the saturation zone and the wetting front of MF are obviously greater than those of UF. When SR occurs, rainfall duration has the most significant influence on infiltration. When macropores are considered, the ponding depth is smaller at the beginning of rainfall, while the effects are not obvious in the later period. Rain intensity and roughness coefficient have significant influences on the ponding depth. Therefore, macropores should not be ignored in the analysis of the slope seepage field.https://www.mdpi.com/2073-4441/13/24/3569heavy rainfallMacropore FlowSlope Runofffinite element methodponding depth |
| spellingShingle | Shanghui Li Zhenliang Jiang Yun Que Xian Chen Hui Ding Yi Liu Yiqing Dai Bin Xue Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method Water heavy rainfall Macropore Flow Slope Runoff finite element method ponding depth |
| title | Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method |
| title_full | Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method |
| title_fullStr | Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method |
| title_full_unstemmed | Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method |
| title_short | Water Field Distribution Characteristics under Slope Runoff and Seepage Coupled Effect Based on the Finite Element Method |
| title_sort | water field distribution characteristics under slope runoff and seepage coupled effect based on the finite element method |
| topic | heavy rainfall Macropore Flow Slope Runoff finite element method ponding depth |
| url | https://www.mdpi.com/2073-4441/13/24/3569 |
| work_keys_str_mv | AT shanghuili waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT zhenliangjiang waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT yunque waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT xianchen waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT huiding waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT yiliu waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT yiqingdai waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod AT binxue waterfielddistributioncharacteristicsundersloperunoffandseepagecoupledeffectbasedonthefiniteelementmethod |