地质学基础地下水.ppt

chapter 5 Groundwater  第五章 地 下 水 * * Definition of groundwater: Groundwater is that part of water which exits in the space of rock’s, soil’ pore below ground surface. Groundwater is precious natural resource to human being, But it’s a factors of reducing the strength of the rock and soils. According to the statistics, Nearly 80% engineering geological problems were caused by the existing of groundwater. So the study on groundwater is very important for a geotechnical(岩土工程) engineer. 地下水的基本概念 The main topic of chaper 5: § 5-1 The physical properties and chemical composition of groundwater § 5-2 The classification of groundwater engineering properties §5-3 Moving law of groundwater § 5-4 The influence of ground water to the engineering § 5-1 The physical properties and chemical composition of groundwater 一.The physical properties of groundwater temperature color taste transparent smell radioactivity Groundwater is a kind of solvent, resolving the soluble composition from rock or soil , so groundwater is full of ions. 1 .The main ion in G Cation阳离子: H+, Na+, K+, Mg2+, Ca2+, Fe2+ Anion 阴离子: OH-, Cl-, SO42-, NO2, HCO3-, CO32-, SiO32-, PO42- HCO3-→bicarbonate CO32-→carbonate SO42-→sulfate Cl→chlorate SiO32-→silicate PO42- →phosphate 二. Chemical composition of groundwater O2→oxygen N2→nitrogen CO2→carbon dioxide →from karst area, → plant respiration H2S→sulfate hydrogen exiting confining environment Esp. Oil layer 2.The main gas composition SiO2 Fe(OH)3 hydroxide Al(OH)3 hydroxide aluminum chemical combination The function of colloid and organism on engineering is indirect, because they may change chemical composition of G. 3.The main co