膨胀土高填方渠堤沉降变形特征研究  

Study on the settlement and deformation characteristics of high-fill canal embankments in expansive soil

作　　者：周学友 于怀昌[2] 孙统领 王闯[2] ZHOU Xueyou;YU Huaichang;SUN Tongling;WANG Chuang(Head Section,Middle Branch of China South-to-North Water Diversion,Co.,Ltd,Nanyang 473000,Henan,China;North China University of Water Resources and Electric Power,Zhengzhou 450046,Henan,China)

机构地区：[1]中国南水北调集团中线有限公司渠首分公司,河南南阳473000 [2]华北水利水电大学,河南郑州450046

出　　处：《水利水电技术（中英文）》2024年第S01期386-391,共6页Water Resources and Hydropower Engineering

摘　　要：南水北调中线工程膨胀土高填方渠堤的工后稳定性是各方关注的焦点,如果渠堤工后沉降大,易导致衬砌面板结构内力变化,影响渠道的运行安全。针对南水北调中线某膨胀土高填方渠堤工后沉降明显的问题,通过该段渠堤现场表面变形、内部变形、地下水位和降雨量监测数据的分析,对其沉降变形特征进行了研究。结果表明:高填方渠堤中渠基膨胀土的垂直表面位移受降雨影响显著,其导致高填方渠堤沉降变形随时间的变化可分为缓降段、陡降段、回弹-稳定-陡降段和回弹段4个阶段;填方高度对渠堤的表面变形和内部变形均存在显著影响,渠堤沉降量随着填方高度的减小而逐渐减小,同时,渠堤内部变形主要集中在孔口以下6~7 m的深度范围内,且指向渠外方向累计水平位移量较大于指向渠内方向的累计水平位移量;结合测压管水位、垂直位移测点及降雨量的变化规律,得到了该段渠基土的表面变形与测压管水位存在较强的相关性,地下水位变化是导致区域地表变形的主要因素。研究成果对膨胀土高填方渠堤工后沉降防治具有科学的参考意义。The post-construction stability of expansion soil high-fill canal embankment in the middle route of the South-to-North Water Transfer project has always been the focus of attention of all parties.The post-construction settlement of the canal embankment is large,which easily leads to the change of internal force of the lining panel structure and affects the operation safety of the canal.The characteristics of settlement deformation is studied by analyzing the monitoring data of surface deformation,internal deformation,groundwater level and rainfall.Through the analysis of on-site surface deformation,internal deformation,groundwater level,and rainfall monitoring data of the embankment,the characteristics of its settlement and deformation are studied.The result show that the vertical surface displacement of the expansive soil in the high fill canal embankment is significantly affected by rainfall,which result in the settlement deformation of the high fill canal embankment changing over time.It can be divided into four stages:gentle descent stage,steep descent stage,rebound-stability-steep descent stage,and rebound stage;The filling height has a significant impact on the surface and internal deformation of the canal embankment.The settlement of the canal embankment gradually decreases with the decrease of the filling height.At the same time,the internal deformation of the canal embankment is mainly concentrated in the depth range of 6-7 m below the orifice,and the cumulative horizontal displacement pointing towards the outside of the canal is greater than that pointing towards the inside of the canal;Based on the changes in water level,vertical displacement measurement points,and rainfall of the pressure pipe,it is found that there is a strong correlation between the surface deformation of the canal foundation soil and the water level of the pressure measuring pipe,and the change of groundwater level is the main factor leading to regional surface deformation.The research result have scientific reference significance

关 键 词：膨胀土 高填方渠堤 现场监测 沉降变形 

分 类 号：TU43[建筑科学—岩土工程]