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1、精选优质文档-倾情为你奉上工程地质论文姓名：肖贵林 学院：国际学院班级：路桥一班学号：6指导老师:肖巧林地下水的地质作用肖贵林（重庆交通大学国际学院，路桥专业2012级一班 学号6）摘要：地下水是地壳中一个极其重要的天然资源,也是岩土三相组成部分中的一个重要组成部分。地下水一方面是饮用、灌溉和工业用水的重要水源之一。另一方面，它与土石相互作用会使土体和岩体的强度和稳定性降低，产生各种不良的自然地质现象和工程地质现象给工程的建筑和正常使用造成危害。诸多的不良地质现象和工程病害，如滑坡、岩溶、潜蚀、土体盐渍化和路基盐胀，多年冻土，地基沉降等都与地下水的存在和活动有关。地下水是工程地质分析、评价和地
2、质灾害防治中的一个极其重要的影响因素.地下水的各种性质决定了它的作用。 关键词：地下水 地质 性质 作用 由于地下水在运动过程中与各种岩土相互作用，溶解某些物质等原因，地下水变成一种复杂的液体。因此，在研究地下水的地质作用前，了解地下水物理性质 和化学性质有实际的意义。 （1），物理性质：地下水物理性质主要指水温、颜色、透明度、嗅和味。化学性质由溶解和分散于地下水中的气体、离子、分子，胶体物质和悬浮固体的成分，微生物及这些物质的含量所决定。 （2），化学性质：地下水中溶解的化学成分同一般天然水中的化学成分基本相同（见天然水水质）。它不同于地表水的是它含有极小量的溶解氧，而CO2则溶解较多；有一
3、些地下水还含有H2S、CH4和氡。导致了纯净的地下水有了臭蛋味，水咸味以及水味苦。 地下水含有某些成分时，对建筑材料中的混凝土、金属等有侵蚀性和腐蚀性。地下水的侵蚀作用：1、剥蚀作用又称潜蚀，它包括以下两种方式。(1)冲刷地下水流体一般分散，流速缓慢，冲刷力微弱，只能冲刷细小的颗粒，使岩石的空隙逐步扩大。但长时间的冲刷，也可造成大型空洞并引起地表塌陷。规模较大的洞穴和裂隙中的地下水流速较快，冲刷力较强。黄土最易被地下水冲刷破坏，因为它主要由粉砂组成，颗粒细小而且松散，同时，黄土含有较多碳酸盐类矿物，易被地下水溶解。(2)溶蚀地下水中含有CO2，易溶解石灰岩或含碳酸盐类矿物的岩石，其分解而成的钙
4、离子和碳酸氢根离子随水流失。由于地下水的运动是发生在岩石空隙中，水与岩石的接触面大，而且地下水流速缓慢，因而其溶蚀作用极为显著。特别是在湿热气候条件下，溶蚀是可溶性岩石遭受破坏的主要原因，并形成特殊的地貌。将以主要为地下水(兼有部分地表水)，对可溶性岩石进行以化学溶蚀为主、机械冲刷为辅的地质作用以及由这些地质作用所产生的地貌，称为喀斯特。地下水的搬运作用和沉积作用1、搬运作用除溶洞水能有较强的机械搬运外，地下水的搬运主要是以化学方式进行，包括真溶液及胶体溶液两种形式。搬运物以重碳酸盐为主，有时氯化物、硫酸盐、氢氧化物、二氧化硅、磷酸盐、氧化锰以及氧化铁等也很重要。2、沉积作用按沉积的方式有以下
5、类型：机械沉积 、化学沉积按化学沉积的场所分以下类型：孔隙沉积、裂隙沉积、溶洞沉积、温泉沉积。（1）按沉积的方式分为以下类型机械沉积，地下暗河流到开阔地段时，因流速降低，可以出现砾石、砂和粘土沉积。它们略有分选和磨圆，粒细，量少。有时在机械沉积物中混有有用矿物，对这些矿物进行研究，可帮助确定地下水的补给源地，甚至指导寻找地下盲矿体。化学沉积，引起化学沉积的主要原因有：地下水流出地表或流入洞穴，所含CO2因压力降低而逸出，水中Ca(HCO3)2分解成CaCO3而沉淀；水温降低，尤其是温泉水流出地表时水温剧降，在泉口附近发生沉淀；水分蒸发，使溶液浓度增加而产生沉淀；此外，胶体物质则是通过胶凝作用发
6、生沉淀。（2）按化学沉积的场所可分以下类型：孔隙沉积，是在孔隙中发生的沉积物有CaCO3、Fe(OH)3、SiO2等，能导致沉积物胶结成坚硬的岩石。如果沉积物围绕某一矿物颗粒发生凝聚，可形成结核。如黄土中的钙质结核与铁锰结核。裂隙沉积，发生在裂隙中。形成脉状沉积体。如方解石脉、石英脉等。矿脉及假化石地下水带的矿物质沿裂隙沉淀下来，常见方解石脉,有时在一些密集而细小的裂隙中，e、n等某矿物沉淀下来，看上去如树枝化石，俗称“假化石”。参考文献： 1. 廉勇 城市建设：下旬 2010(6) 2. 赵春明 城市道桥与防洪 2010(10) 3. 曹辉 民营科技 2013(1) 4. 窦明健 公路工程地
7、质，北京，人民交通出版社 20135. 王学雷 华中师范大学学报：自然科学版 2001,35(2) 6. 刘广明 杨劲松 等 土壤学报 2002,39(3) 7. 史文娟 沈冰 汪志荣 王文焰 农业工程学报 2007,23(2) 8. 童潜明 国土资源导刊（湖南） 2004,1(1)刘广明 杨劲松 土壤学报 2003,40(1) 9. 陈康娟 王学雷 长江流域资源与环境 2002,11(3) Due to the groundwater in the process of movement and all kinds of rock and soil interaction, dissolve
8、 certain substances, groundwater into a complex liquid. Therefore, before the research under the action of groundwater, understand the physical properties and chemical properties of groundwater has practical significance.(1), physical properties, physical properties of groundwater refers to water te
9、mperature, color, transparency, smell and taste. Chemical properties by dissolution and dispersion in gases, ions, molecules in the groundwater, colloidal substances and the composition of suspended solid, microorganism is determined, and the content of the material.(2), chemical properties, the che
10、mical composition of dissolved in groundwater with the same general chemical composition of natural water (see natural water quality). It is different from surface water is that it contains a tiny amount of dissolved oxygen, while CO2 dissolves more; There are some groundwater contains H2S, and CH4
11、and radon. Led to the pure water smell of rotten eggs, water salty, and bitter taste.Groundwater contains some ingredients, concrete in building materials, metal and so on are aggressive and corrosive. Groundwater erosion: 1, denudation, also called internal erosion, it includes the following two wa
12、ys.(1) washGroundwater flow generally scattered, the velocity is slow, scouring force is weak, can only be washed fine particles, make the space rocks gradually expanding. But for a long time scour, also can cause large cavity and causes the surface subsidence. Larger cave and fissure of groundwater
13、 flow faster, scouring force is stronger.Loess most easily destroyed by groundwater erosion because it is mainly composed of silt, fine and loose particles, at the same time, the loess contains more carbonate minerals, vulnerable to water dissolved.(2) dissolutionGroundwater containing CO2, easy dis
14、solved limestone or contain carbonate mineral rocks, the decomposition of calcium ions and bicarbonate ions with the water erosion. Due to groundwater movement is one of the gaps in the rock, water and the contact surface of the rock, and groundwater flow velocity is slow, and its dissolution was ex
15、tremely significant. Especially in hot and humid climate condition, the dissolution is the main cause of soluble rock destruction, and forms the special landform. Will be mainly for groundwater (both part of the surface water), the soluble rock is given priority to with chemical corrosion, under the
16、 action of mechanical erosion is complementary, and produced by these geological landscape, known as karst.Groundwater in the transportation and deposition1, transportation,Except the cave water can have stronger mechanical handling, handling mainly of groundwater chemical way, including the true so
17、lution and colloidal solution in two forms. Sometimes handling content is given priority to with bicarbonate, chloride, sulfate, hydrogen chloride, silica, phosphates, manganese oxide and iron oxide is also very important.2, sedimentation,According to sedimentary pattern has the following types: mec
18、hanical, chemical deposition sedimentationAccording to the place of chemical deposition in the following types: pore sedimentary, fractures and caves, hot springs depositing.(1) the way deposit is divided into the following typesMechanical sedimentary, dark underground rivers to the open area, due t
19、o lower velocity, can appear gravel, sand and clay deposits. Their separation and slightly rounded, grain, quantity is little. Sometimes in mechanical mixed with useful minerals in sediments, the study of these minerals, helps to determine the recharge source of groundwater, and even guide undergrou
20、nd blind orebodies.Chemical deposition, the main cause of chemical deposition are: surface or groundwater flows into the cave, containing CO2 to escape due to lower the pressure, the water Ca (HCO3) 2 break down into CaCO3 and precipitation; The water temperature is reduced, especially the hot sprin
21、g water outflow water temperature drops when the earths surface, near the spring precipitation occurred; Moisture to evaporate, make the solution concentration increases with the precipitation; In addition, colloidal substance by gelatination settling.(2) by chemical deposition area can be divided i
22、nto the following types:Pore deposition, happened in the pore sediment CaCO3, Fe (OH) 3, SiO2, cementation can result in sediment into hard rock. , if the sediment around a particular mineral grains condensation can form of TB. Such as tuberculosis calcium and iron and manganese nodules in the loess
23、.Fissure deposits, occurring in the fracture. Form a vein deposit. Such as calcite veins, quartz vein. Vein and fake fossils - groundwater with minerals along the fracture settle, common calcite veins, sometimes in some densely populated and tiny fracture, Fe, Mn, such as a mineral precipitation down, looks like the branches of the fossil, commonly known as fake fossils 专心-专注-专业