坝基计算范围对黏土心墙坝浸润线的影响

The Effect of Calculation Scope of Dam Foundations to Phreatic Surface of Clay Core Dams

在数值分析中,透水坝基的计算范围对土石坝坝体浸润线计算结果有较大的影响。通过大量数值计算,研究了黏土心墙坝心墙与坝基不同渗透系数比值、地基不同计算范围对坝体内浸润线影响规律。研究表明,随着心墙与坝基渗透系数比值的增大,坝基计算要求深度逐渐减小,一般取0.3～0.8倍坝底宽度较适宜;当坝基渗透系数小于心墙渗透系数1/2时,可以按不透水坝基计算;坝基的计算宽度沿上游延伸长度建议取1.0倍坝高。

The calculation scope of permeability foundation will bring great errors to the phreatic surface of earth dams in numerical simulation. The influence on the phreatic sur：[ace of clay core dams are respectively investigated by different permeability coefficient ratios of clay core walls and dam foundations, and calculation scope through a large number of steady seepage analyses. The results show that the rational calculation depth of dam foundations in numerical models decreases with the increment of the permeability coefficient ratios of core walls to foundations. The rational calculation depth is 0. 3-0. 8 times of the dam base width. The dam foundation of clay core dams can be considered as an impermeable foundation when its permeability coefficient is less than 1/2 times of clay core walls. The calculation length along the dam upstream is recommended 1.0 times of the dam height.