心墙防渗土料原位渗透与室内渗透试验对比研究

Research on the Comparison Between In-situ and Indoor Permeability Test of Core Impermeable Soil

土质心墙堆石坝是目前水电站设计的主要坝型之一,其坝高已达到300 m级,该坝型解决的首要问题是心墙防渗土料的抗渗性能。为得到贴近实际的渗透系数,对几个水利水电工程心墙防渗土料的原位渗透和室内渗透试验成果进行对比分析。研究发现原位渗透试验所得渗透系数基本上都大于1×10-5cm/s,超出规范要求,而室内渗透试验成果基本上都小于1×10-5cm/s。从边界条件和外界影响等因素综合分析,室内渗透试验方法所得渗透系数更贴近实际,该结论对于类似工程设计和施工具有一定的参考意义。

At present, soil core rock-fill dam is one of the main dam types in the design of hydropower stations, with the highest dam of 300 m level. The principal problem of this dam type lies in the permeability resistance of core imperme- able soil. In order to get the permeability coefficient which is close to its actual value, the test results of core imperme- able soil obtained by in-situ and indoor permeability tests in several water resources and hydroelectric engineerings were compared and analyzed. It was found that the permeability coefficients obtained by in-situ permeability tests of imperme- able soil were mostly greater than 1 × 10-5 cm/s, which exceeded specification requirements, but permeability coeffi- cients obtained by indoor permeability tests were mostly smaller than 1 × 10-5 crn/s. According to the comprehensive analysis of boundary conditions and external influences, it was concluded that the permeability coefficients obtained by indoor permeability tests were closer to the reality. This study will provide some reference for the design and construction of similar engineerings.