糯扎渡大坝心墙高孔隙水压力研究  

Study on High Porewater Pressure in Core Wall of Nuozhadu Dam

作　　者：倪沙沙 张兆军 赵新波[1] NI Sha-sha;ZHANG Zhao-jun;ZHAO Xin-bo(Schoolof Science,Qingdao University of Technology,Qingdao 253000,China)

机构地区：[1]青岛理工大学理学院,山东青岛253000

出　　处：《水电能源科学》2025年第2期132-136,共5页Water Resources and Power

基　　金：山东省自然科学基金博士基金项目(ZR2018BA017);国家自然科学基金青年基金项目(52104004)。

摘　　要：较高的孔隙水压力将直接影响高心墙坝前期的渗流安全,甚至引起心墙的水力劈裂。因此,以糯扎渡高砾石土心墙堆石坝为例,基于比奥理论和Duncan-Chang E-υ模型,采用有限元法对该坝进行了固结计算,并与大坝孔隙水压力实测值进行了比较。结果表明,填筑期孔压实测值大于计算值,心墙填筑完成时,各测点孔压实测值均大于孔压计算值,相对误差范围约为9.3%~12.7%。而孔压消散速度的计算值大于实测值,导致大坝竣工后水库继续蓄水时,孔压实测值表现为逐渐增大,计算值却表现出逐渐减小的消散趋势。分析出现这一矛盾现象的主要原因为当前有限元计算体积应变的预测精度不高,高坝心墙在不同高程处应力条件相差较大,使得有限元计算中心墙的固结参数无法准确确定。Higher pore water pressure will directly affect the seepage safety of the high core wall dam in the early stage,and may even lead to the hydraulic fracturing of the core wall.Taking the Nuozhadu earth-rockfill dam with gravel soil core wall as an example,based on Biot's theory and Duncan-Chang E-υmodel,the finite element method was used to calculate the consolidation of the dam.The calculated results were compared with the measured data of the pore water pressure of the dam.The results show that the measured values of the pore pressure during the filling period are greater than the calculated values.When the core wall filling is completed,the measured values of the pore pressure at each measuring point are greater than the calculated values of the pore pressure,and the relative error range is approximately 9.3%-12.7%.However,the calculated value of the pore pressure dissipation rate is greater than the measured value.As a result,when the reservoir continues to store water after the completion of the dam,the measured value of the pore water pressure gradually increases,while the calculated value shows a gradually decreasing dissipation trend.The main reason for this contradictory phenomenon is that the current prediction accuracy of the finite element calculation of volumetric strain is not high,and the stress conditions of the core wall of high dam vary greatly at different elevations,making it impossible to accurately determine the consolidation parameters of the core wall in the finite element calculation.

关 键 词：高土石坝 比奥固结 有限元分析 孔隙水压力消散 

分 类 号：TV641.4[水利工程—水利水电工程]