花岗岩残积土坡对短历时强降雨的水文响应  

Hydrological Response of Granite Residual Soil Slope to Short-Duration Heavy Rainfall

作　　者：赖增荣 简文彬[1,2] 林昀昭 朱祖腾 吴宜龙 Lai Zengrong;Jian Wenbin;Lin Yunzhao;Zhu Zuteng;Wu Yilong(Zijin College of Geology and Mining,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Key Laboratory of Geohazard Prevention,Fuzhou University,Fuzhou,Fujian 350108,China)

机构地区：[1]福州大学紫金地质与矿业学院,福建福州350108 [2]福州大学福建省地质灾害重点实验室,福建福州350108

出　　处：《水土保持通报》2024年第4期135-142,共8页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“台风暴雨型滑坡多级监测预警系统研究”(NO.41861134011);“闽台高植被覆盖区台风暴雨型滑坡孕灾环境、成灾机制与动态预警”(U2005205)。

摘　　要：[目的]探究短历时强降雨条件下边坡土体的入渗规律,揭示地质灾害的成因和机理,为该地区地质灾害的形成机理和预警预报工作提供科学依据。[方法]针对2022年5月26—27日福建省龙岩市武平地区因强降雨诱发的浅层流态型滑坡事件,在地灾点典型滑坡处开展原位人工模拟降雨入渗试验,采用土壤水分计、张力计、孔隙水压力传感器和雨量计等监测装置进行系统观测,同时,结合有限元软件模拟不同降雨强度下雨水入渗过程,以深化对入渗规律的理解。[结果]在靠近坡体表面的位置,土体的体积含水率增加幅度较大,随着埋深的增加,增加幅度逐渐减小;边坡各处入渗速度大小表现为:坡顶<坡中≈坡脚;在短历时强降雨作用下,孔隙水压力呈现逐渐增大并达到峰值后稳定的趋势,值得注意的是,在距离坡表120 cm处的孔隙水压力值较其他两个深度的孔隙水压力值大,这可能是由于该处的土层渗透性较低,形成了一个相对滞留的水位,数值模拟结果也较好地反映了这一规律。[结论]在短历时强降雨的情况下,边坡土体的入渗过程极为复杂,且对地质灾害的触发起着关键作用。其入渗特性受降雨强度、土层深度及渗透性等多重因素的综合影响。[Objective] The infiltration laws of slope soil bodies under short-duration heavy rainfall were investigated to reveal the causes and mechanisms of geological disasters in order to provide a scientific basis for the formation mechanism,early warning,and prediction of geological disasters in the region.[Methods] Regarding the shallow flow-type landslide event induced by heavy rainfall in Wuping area,Longyan City,Fujian Province,on May 26—27,2022,an in-situ artificial rainfall infiltration test was conducted at the typical landslide site of the geological disaster area.Systematic observations using monitoring devices such as soil moisture meters,tensiometers,pore water pressure sensors,and rain gauges were conducted.At the same time,finite element software was used to simulate the rainwater infiltration process under different rainfall intensities to deepen the understanding of the infiltration law.[Results] The increase in volumetric water content of the soil was greater near the surface of the slope and decreased with increasing burial depth.The infiltration rate of the slope was fastest at the foot and middle of the slope and slowest at the top of the slope.Under the impact of short-term intense rainfall,the pore water pressure increased gradually,peaked,and then stabilised.Notably,the pore water pressure at a distance of 120 cm from the slope surface was higher than that at the other two depths.This may be attributed to the lower permeability of the soil layer at this location,which resulted in a relatively stable water level.The numerical simulation results reflected this pattern effectively.[Conclusion] The infiltration process of the slope soil is extremely complex in the case of short-duration heavy rainfall and plays a crucial role in triggering geological disasters.Its infiltration characteristics are comprehensively influenced by multiple factors such as rainfall intensity,soil layer depth,and permeability.

关 键 词：原位模拟降雨 水文响应 入渗 数值模拟 

分 类 号：TU413[建筑科学—岩土工程] P642.2[建筑科学—土工工程]