涔天河渠道土质边坡失稳分析与对策研究  

Instability analysis and countermeasure research of soil slope in Centianhe canal

作　　者：李毅[1,2] 程宝平 何学春[3] 张贵金[1,2] 梁经纬[1,2] LI Yi;CHENG Bao-ping;HE Xue-chun;ZHANG Gui-jin;LIANG Jing-wei(School of Hydraulic and Environmental Engineering,Changsha University of Science&Technology,Changsha 410114,China;Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province,Changsha University of Science&Technology,Changsha 410114,China;Hunan Lishui Hydro&Power Co.,Ltd.,Changsha 410007,China)

机构地区：[1]长沙理工大学水利与环境工程学院,湖南长沙410114 [2]长沙理工大学水沙科学与水灾害防治湖南省重点实验室,湖南长沙410114 [3]湖南澧水流域水利水电开发有限责任公司,湖南长沙410007

出　　处：《长沙理工大学学报（自然科学版）》2022年第1期53-63,共11页Journal of Changsha University of Science and Technology:Natural Science

基　　金：湖南省自然科学基金资助项目(2019JJ50336);湖南省水利科技项目(2017-230-4,XSKJ2018179-04);湖南省教育厅科研项目(19B018)。

摘　　要：【目的】探究因不合理开挖导致的渠道土质边坡的失稳问题。【方法】以涔天河干渠切方土质边坡为例,用FLAC^(3D)模拟其施工过程,复核开挖设计方案,分析边坡开挖诱发牵引式滑坡的破坏机理。针对失稳土质边坡,提出边坡锚固支护、渠道衬砌(方案一)和边坡锚固、明渠变更暗涵(方案二)两种加固处置方案,并分析了处置措施的有效性。【结果】对边坡使用方案二支护加固后,其稳定性明显优于方案一,最不利工况的安全系数可达1.18以上,边坡的总体安全性可以得到保障,而且能最大限度地减小边坡开挖对地表变形的影响,研究成果可指导边坡后期施工的顺利进行。基于TOUGH2模拟脉动灌浆,通过精细化模拟灌浆过程,确定灌浆方案和参数,并以质量分数的形式在FLAC^(3D)中通过插值修改强度参数,采用强度折减法计算开挖边坡安全系数,确定预加固设计方案。【结论】对于类似边坡,应预加固再开挖,预加固措施优先推荐脉动灌浆方式,以提高边坡的整体稳定性。采用3排孔、孔排距2 m、孔深8 m的布孔方案后,边坡安全系数可达到1.50以上。与直接开挖相比,该方案有效降低了边坡垮塌的风险,研究成果可供类似工程参考。[Purposes]The paper aims to explore the problem of soil slope instability of canal caused by unreasonable excavation.[Methods]Taking the incised soil slope of Centianhe trunk canal as an example,its construction process was restored by FLAC^(3D) numerical simulation,the excavation design scheme was reviewed,and the failure mechanism of traction landslide induced by slope excavation was analyzed.Aiming at the instable soil slope,two reinforcement treatment schemes were put forward,namely the scheme 1(slope anchoring support,canal lining)and the scheme 2(slope anchoring,hidden culvert replacing open channel),and the effectiveness of the treatment measures was analyzed.[Findings]The stability of the slope reinforced by the scheme 2 is obviously better than that of the scheme 1,the safety factor can reach more than 1.18 under the most unfavourable condition,and the overall safety of the slope can be guaranteed.Moreover,the influence of slope excavation on surface deformation can be minimized,and the research results can guide the smooth construction of slope in the later period.The pulsating grouting was simulated based on TOUGH2,the grouting scheme and parameters were determined by finely simulating the grouting process,and the strength parameters were modified by interpolation in FLAC^(3D) in the form of mass fraction.The strength reduction method was used to calculate the safety factor of the excavated slope to determine the pre-reinforcement design scheme.[Conclusions]For similar slopes,they should be pre-reinforced before excavation,and the pre-r einforcement measures should give priority to the pulsating grouting method to improve the overall stability of the slope.The slope safety factor reaches more than 1.50 after using the hole-layout scheme of 3 rows of holes,2 m hole spacing and 8 m hole depth.Compared with the direct excavation,the scheme can effectively reduce the risk of slope collapse,and the research results can be used as a reference for similar projects.

关 键 词：渠道土质边坡 稳定性分析 锚固支护 灌浆预加固 不合理开挖 

分 类 号：TV223[水利工程—水工结构工程]