【作者】 沈飞；

【导师】 曹净；

【作者基本信息】 昆明理工大学 ， 岩土工程， 2010， 硕士

【摘要】 随着社会经济的发展,为了适应人类生产、生活的需求,越来越多的大型工程项目建设实施,由于农业用地和生产用地的矛盾加剧和环境保护等要求,大型的工程项目往往建设在地质、地形条件复杂的地区,而这些区域的地质、地形条件的复杂性使得地下水条件也变得复杂。场地的建设过程中,将对地表水、地下水产生扰动,改变其补给、径流、排泄条件。若治理不当,地表水在洪水期可能会淹没场地,严重影响厂区的正常生产；地下水将在场地内产生壅积,浸泡地基土(尤其是填筑土),使地基土(尤其是填筑土)的强度降低,危及场地的稳定性和厂房及其它实施的正常运行。如何较为准确的模拟地下水渗流场及预测场地平整中的涌水量,为大型建设场地制定合理的防排渗措施提供依据,成为日益关注的课题之一。本文以拟建的西昌某钢铁新基地场地平整前后的地下水变化为研究对象,在野外地质调查及区域水文地质特征分析的基础上,研究地下水对大型工程建设的影响,提出工程水文地质的意义,建立概念模型及数学模型,利用GMS软件,运用有限差分法,对场地平整前后的地下水变化进行数值模拟,预测场地平整后,增设盲排系统的条件下,地下水渗流场及涌水量变化情况,研究表明：1、拟建西昌钢铁基地地下水动态成因类型属于气象型,大气降水是其主要补给源；径流模式是波态型,降水补给地下水其渗透和径流都有一定的深度和长度,地下水具有明显的分带性；地下水排泄主要为侧向排泄及泉点渗水。2、场区内的潜水层主要接受区内地表水体和降雨补给,而承压水层主要接受降雨补给；降雨对地下水的补给滞后性较明显。昔格达组的粘土岩和粉砂岩互层,并且粘土岩节理裂隙发育,补、径、排条件极其复杂。根据地下水分水岭与次级分水岭位置、埋藏分布、以及补、径、排条件,可将场地分为三个相对独立的水文地质单元：罗家沟水文地质单元、范家沟-小桥沟水文地质单元和王家村水文地质单元。依据研究区域的地质背景和划分的各水文地质单元的水文地质特征,建立模拟区的水文地质概念模型、数学模型,通过模型的校正和调参,模拟结果与实际观测地下水水位基本吻合,获取了一套适合于拟建场地的实际水文地质参数(渗透系数、给水度等)。3、利用GMS对场地平整前后的地下水渗流场进行了模拟并对比分析,得出：(1)场平后挖方区地下水水位下降,填方区地下水位有所上升。挖方区地下水位下降幅度为8-30m,填方区地下水位上升幅度为7-22m。(2)原王家村水文地质单元与罗家沟水文地质单元之间地下水分水岭将不明显。场平后在局部边坡地段将形成地下水位陡降面,导致坡体地下水渗流压力较大,影响到边坡的稳定性。4、对场地平整后地下水渗流场与增设盲排系统的地下水渗流场进行对比分析,并与实测值对比得出：(1)增设盲排系统后,场地地下水水位有较明显的下降,特别是在盲排措施的周围,水位下降4-12m,且与实测地下水水位较为相近,说明盲排措施是有效的,布置也较合理。(2)场地平整后1号出口(罗家沟与范家沟出口)的日涌水量为1452.22m3/d；2号出口(王家村出口)的日涌水量为271.36m3/d,与实测值较为接近,随着场地的后期建设,地表固化处理措施的实施,大气降水补给量减少,日涌水量将有所减小并最终稳定。更多还原

【Abstract】 With the development of social and economic, in order to adapt to the people’s demands on production and living, more and more large-scale construction projects are carried out. But because the conflicts about the land between the agricultural and production and the requirements of environmental protection, large-scale construction projects are often in the areas which are complex in geological, topographical conditions. So these region’s ground water condition also becomes complex.In the construction process, the surface water and the ground water will be perturbed, and change their conditions of recharge, runoff, excretion. If these circumstances are out of control, the surface water will possibly submerge the location in the flood period, which will seriously influence factory district regular production; The ground water will gather in the location, soaks the foundation soil (particularly reclamation soil). The intensity of the foundation soil (particularly reclamation soil) reduces. The location’s stable will be subjected to threat, and the workshop and the other implementations won’t be operate in normal. So how to make the simulation to the groundwater seepage field and forecast the water inflow more accuratly can provide the basis for making the reasonable measures to against drainage in the large-scale construction location, and become one of the topics of increasing concern.This paper takes the changes of the groundwater in one of steel flat in Xichang in plans as the research object. On the base of previous studies, the paper studys the groundwater to the large-scale construction projects’s influences, and proposes the concept of Hydrology geology in the projects. On the bases of field geological surveys and analysis of regional hydro-geological characteristics, the paper sets up the conceptual models and the mathematical model. By using GMS software and the finite difference method, the paper imitates the changes of the groundwater in the location in numerical simulation, and predicts the chages of the groundwater seepage field and water inflow in the conditions of the location in flat and drainage systems are carried out.The research shows that:1. In one of Metallurgical base in Xichang plans to construct, the genetic type of the groundwater’s dynamic belongs to the Weather-type and the atmospheric precipitation is the main supply source.The mode of run-off is the wave-state type and the groundwater’s run-off has a certain depth, length and has the obvious zonation. The discharge of groundwater is mainly lateral excretion and the spring water gushing.2. In the field the groundwater in the aquifer level mainly Supply by the surface water and the rainfall, but in the confined water layer the groundwater mainly Supply by the rainfall. The hysteresis quality for the rainfall recharge to groundwater is obviously. In the Xigeda group clay stone and siltstone interbed, and the clay stone jointing crevasse is growth, so in the field the groundwater’s recharge, runoff and drainage conditions is extremely complex. According to the positions of watershed and the secondary watershed, the groundwater’s recharge, runoff and drainage conditions, the field may divide into three relatively independent geohydrologic units:Luojiagou geohydrologic unit, Fanjiagou geohydrologic unit and Wangjiacun geohydrologic unit. According to the geological background of the study area and hydro-geological characteristics, the study sets up the hydro-geological conceptual model and mathematical model in the simulation area, and by means of repeated calibration and scheduling, which obtained a set of hydro-geological parameters (permesbility coefficient and specific yield etc.).3. The paper made the comparisons to the groundwater seepage field of the site before and after the formation in the numerical simulation, and analysed the results. (1)After the site formated, the groundwater level falls by 8～30 metres in the earth cutting area; the groundwater level rises by 7～22 metres in the spackling area.(2)The ground water divide between Luo Jia Gou hydrogeologic units and Wang Jia Cun hydrogeologic units won’t be obvious. After the site formated, some slopes will be not stable, on account of the height of water and the greater pressure on groundwater seepage in the slope.4. The paper made the comparisons to the groundwater seepage field of the site after the formation and the drainage systems setted, and compared with the measured values, and analysed the results.(1)After the drainage systems setted, the groundwater has been significantly decreased. Especially around the drainage systems, the groundwater decrease to 4～12 metres. The errors between the measured values and simulation values are in the allowable range. The groundwater level has been effectively controlled, so the drainage systems are valid.(2)The water inflow is 1452.22m3/d in the utter of 1#; The water inflow is 271.36m3/d in the utter of 2#. They both surpass the actual value slightly. Along with the site construction, for example hardened surface, the recharge will be reduced, so the water inflow everyday will decrease and eventually stabilize.更多还原