土石坝心墙孔压及其分布特征形成机理研究

Study on Pore Pressure and Its Distribution Characteristics in Core Wall of Earth Rock Dam

心墙孔压对大坝稳定性有重要影响。为了进一步掌握土石坝心墙孔压的变化趋势和分布特点,提出流固耦合分析法,并将数值模拟计算结果和实测值进行对比。结果表明,不排水条件下的流固耦合分析方法效果较好,具有高效、简便的优点,能够较好地对心墙的变形和孔压进行模拟;初始饱和度对计算孔压时程影响较大,计算孔压随着初始饱和度的增大而增大,两者为非线性关系;最大监测值小于最大计算值,表明现有渗压计的监测覆盖范围不足,可适量提高渗压计的数量;心墙饱和度的随机性是导致大坝心墙孔压分布不均匀的主要因素;平均饱和度一致时,心墙沉降值基本不会受到饱和度随机性分布的影响。

The core wall pore pressure has an important influence on the stability of the dam.In order to further understand the variation trend and distribution characteristics of the core wall pore pressure of the earth rock dam,fluid-solid coupling analysis method is proposed,and the numerical simulation results and measured values are compared.The research results show that the proposed fluid-solid coupling analysis method under the condition of no drainage is effective,efficient and simple,and can better simulate the core wall deformation and pore pressure.The initial saturation has a great influence on the time history of calculating pore water pressure,which is shown by the nonlinear relationship between the calculated pore water pressure and the initial saturation.The maximum monitoring value is less than the maximum calculated value,which means that the monitoring coverage of existing osmometers is insufficient,and the number of osmometers can be increased appropriately.The randomness of core saturation is the main factor that causes the non-uniform pore pressure distribution of the dam core.When the average saturation is the same,the core settlement value is basically not affected by the random distribution of saturation.