波动水位影响下的滨岸稳定性预警技术研究  

Research on Forewarning Technology of Estuary Riverbank Stability under the Influence of Fluctuating River Level

作　　者：周侗[1] 陈伟伦 王俊[1] 孔俊[1] ZHOU Tong;CHEN Wei-lun;WANG Jun;KONG Jun(Key Laboratory of Coastal Disaster and Protection(Hohai University),Ministry of Education,Hohai University,Nanjing 210098,Jiangsu Province,China)

机构地区：[1]海岸灾害及防护教育部重点实验室河海大学,江苏南京210098

出　　处：《中国农村水利水电》2023年第12期77-84,93,共9页China Rural Water and Hydropower

基　　金：国家重点研发计划项目(2021YFB2600200);国家自然科学基金面上项目(51979095)。

摘　　要：河口地区地表水波动会诱发滨岸潜水层内地下水位的震荡,并呈现出与河道水位非同步性的涨落过程。落潮阶段,河道边坡内地下水位高于地表水位,饱和区和饱和区持水量较大,容易诱发岸坡失稳。为此,通过改进BSTEM模型,并将其与考虑非饱和流运动的地下水模型SUTRA相耦合,提出了适用于复杂河口地区的崩岸预警模型SUBS。研究结果表明:河口地区地表水波动诱发的潜水层地下水波动具有较强的迟滞性,边坡安全系数和最不利崩塌面随潮汐周期性变化,涨潮期安全系数增加,落潮期由于地下水的排水滞后性,导致岸坡安全系数降低。尤其是在大潮期的落潮阶段,水位快速降落,岸坡上浸润面的出现会进一步增加岸坡崩塌的风险。进一步对比均质和非均质边坡的稳定性,结果表明岸坡内土壤黏聚力对边坡的稳定性影响较大,上层为黏土,下层为砂土的复合结构岸坡的稳定性要高于岸坡组成为低黏聚力均质砂土的情况,此时需要更加关注地下水位波动的影响。通过耦合地下水模型,考虑地下水位的实时波动特征,拓展了传统BSTEM模型的应用范围,为河口地区边坡稳定性预测提供了新的研究手段。The tidal level fluctuations in the estuarine area trigger fluctuations in the water level of the coastal diving layer,exhibiting a nonsynchronous fluctuation pattern with the tidal level.This phenomenon has a profound impact on the stability of the bank slope.The varying water levels disrupt the equilibrium and increase the risk of slope instability,posing significant challenges to the structural integrity and long-term stability of the slope.During the ebb tide stage,the groundwater table within the interior of the bank slope tends to be higher than the tidal level.Consequently,this leads to a greater water holding capacity in the saturated area and creates conditions that are more suscepti⁃ble to inducing bank slope collapse and instability.The higher water levels during this stage increase the potential for instability,posing a sig⁃nificant risk to the structural integrity and stability of the bank slope.In order to address the specific challenges of complex estuaries,this pa⁃per presents SUBS,a bank collapse warning model.SUBS is developed by improving the BSTEM(Bank Stability and Toe Erosion Model)and coupling it with SUTRA(Saturated-Unsaturated Transport),a groundwater model that incorporates unsaturated flow movement.By com⁃bining these advancements,SUBS provides a comprehensive and accurate framework for predicting bank collapse events in intricate estuarine environments, contributing to improved bank collapse risk assessment. The research findings show that the fluctuation of groundwatercaused by the fluctuation of tidal level in estuarine area has quite a strong hysteretic property. The Factor of Safety of the bank slope and themost dangerous failure surface will change periodically with the tide. And the Factor of Safety will increase during the rising tide, reflectingimproved stability. Conversely, during the ebb tide, the Factor of Safety decreases due to the lag in groundwater drainage. Especially duringthe ebb stage of the spring tide, the water level plummets rapidly, significantly height

关 键 词：BSTEM 耦合模型 非饱和流 地下水位 岸坡稳定 

分 类 号：TV147[水利工程—水力学及河流动力学]