Seepage Calculation and Analysis of the Upstream Earth-Rock Cofferdam of the Pinecone Hydropower Station

摘要

The upstream cofferdam of the Pinecone Hydropower Station was an upstream earth-rock cofferdam built on the deep overburden layer of upstream foundation pit, which has many characteristics such as big reservoir capacity in front of the cofferdam, deep foundation pit behind the cofferdam and long anti-seepage time. In order to provide reference and a basis for seepage control construction, the sensitivity analysis on permeability coefficients of the seepage control system was made to analyze the seepage characteristics of upstream cofferdam at design water level and to discuss the permissible value range of permeability coefficients. The calculation results show that correct and reasonable seepage control measures are able to realize an effective control of the seepage field. Besides, the engineering design parameters are obtained when the optimization analysis on permeability coefficients meets the seepage control requirements, and thus provide the basis for engineering optimization design.