Influence of grass plantation on the rainfall-induced instability of gentle loose fill slope  

作　　者：Pei Tai Fan Wu Bohan Bai Zhaofeng Li Rui Chen Lulu Zhang 

机构地区：[1]School of Civil and Environmental Engineering,Harbin Institute of Technology,Shenzhen,Shenzhen 518055,China [2]Guangdong Provincial Key Laboratory of Intelligent and Resilient Structures for Civil Engineering,Shenzhen 518055,China [3]State Key Laboratory of Ocean Engineering,Collaborative Innovation Centre for Advanced Ship and Deep‑Sea Exploration,Shanghai Jiaotong University,Shanghai 200240,China

出　　处：《Biogeotechnics》2024年第4期52-57,共6页生物岩土技术（英文）

基　　金：National Key R&D Program of China(2021YFC3001000);the National Natural Science Foundation of China(52239008,52108311,and 52025094);the Shenzhen Science and Technology Program(KQTD20210811090112003 and GXWD20231130125225001)for financial supports.

摘　　要：The understanding of rainfall-induced landslides on gentle, loose-fill slopes is limited in comparison to steep slopes. Hence, two physical model tests were conducted on silty sand slopes under continuous rainfall: one on a bare slope and the other on a slope planted with ryegrass. The slope angle of 25° is much lower than the internal friction angle of slope material (34.3°), which makes the model test fall well into the category of gentle slope. For the initially unsaturated bare slope, a rainfall event with return period of 18 years could trigger a rapid and retrogressive global sliding, which differs from previous findings that gentle slopes would only experience shallow failure. A sudden increase in pore-water pressure was simultaneously observed, which might be generated by the wetting-induced collapse of unsaturated loose soil. On the other hand, the stability of the slope with grass plantation was significantly enhanced, and it was able to withstand rainfall event more severe than those with a return period of 100 years, with only minimal deformation. The results suggest that the gain in shear strength due to ryegrass roots surpasses the additional sliding force caused by the increased water retention capability. Additionally, it is found that the abrupt change in pore pressure was no longer indicative of slope failure in the case of the grass-reinforced slope.

关 键 词：Gentle slope Silty sand RYEGRASS RAINFALL Failure pattern 

分 类 号：P64[天文地球—地质矿产勘探]