摘要
渗漏问题是涉及水库安全和经济运行的关键问题之一,为了有效增强基岩结构面内软弱充填物的抗渗性及渗透稳定性,降低坝基扬压力,控制坝基渗漏及两岸绕渗,通常在坝基及两岸山体内设置一定深度的灌浆帷幕,形成防渗体系.因此,灌浆帷幕的耐久性与大坝安全运行及管理息息相关.为了研究灌浆帷幕防渗性能的衰减过程,采用COMSOL Multiphysics软件,建立了坝基渗流场、化学场以及溶质运移场的三场全耦合有限元数值模型,研究帷幕在渗透力作用下,溶质的溶解-沉淀和迁移-扩散随时间的变化过程.研究结果表明:在库水的长期侵蚀和溶解作用下,帷幕缓慢地不断发生溶解侵蚀,其微观结构发生改变,帷幕中胶凝材料逐渐减少,使其渗透系数逐渐增大,防渗性能逐渐衰减;帷幕不同部位的溶蚀程度不同,底部溶蚀量最大,其次为上部,中部溶蚀量最小,因此帷幕底部是灌浆的质量控制重点区域;靠近坝基上游侧的帷幕溶蚀量高于下游侧.
Leakage is one of the key issues related to the reservoir's safety and economic operation.In order to effectively enhance the anti-permeability and stability of the bedrock with weak fillings and reduce uplift pressure of dam,control seepage in the dam foundation and around,grouting curtain is generally setting in the dam foundation and on both sides of the mountain which creates a seepage control system.Therefore,the durability of grouting curtain is closely related to the dam's safety operation and management.In order to know the process of the grouting curtain's attenuation,COMSOL Multiphysics is used to establish a three fully coupled numerical model consist of solute transport,dissolution and seepage.It is indicated that with the long-term erosion and dissolution under the effect of water flow,the curtain dissolves continuously that leads to the change of microstructure and shrinks curtain's gelled material,making the increase of its permeability coefficient.However,the erosion quantity is biggest on the bottom of the curtain while it dissolves least in the middle,which makes bottom of the curtain to be the key area.What's more,dissolution quantity of the upstream side is higher than the downstream side.
作者
徐建伟
徐青
XU Jianwei;XU Qing(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)
出处
《武汉大学学报(工学版)》
CAS
CSCD
北大核心
2016年第2期206-211,共6页
Engineering Journal of Wuhan University
基金
湖北省自然科学基金面上项目(编号:2015CFB544)
关键词
灌浆帷幕
耐久性
渗流场
化学场
溶质运移场
全耦合
grouting curtain
durability
seepage field
chemical field
solute transport field
fully coupling
