太原盆地地面沉降模拟

发布时间：2018-12-13 08:46

【摘要】：太原盆地地处山西省中部,是我国重要的煤炭能源基地,同时也是我国典型的水资源缺乏地区。近年来,随着这区内社会经济的发展,地下水超采越来越严重,由此引发了严重的地面沉降。地面沉降是一种世界普遍存在的缓变型地质灾害,造成的危害具有隐蔽性和长期性,严重制约了经济社会的可持续发展。如何有效防治地面沉降成为一个研究热点。太原盆地是我国地面沉降灾害典型代表,前人做了大量的定性研究,达成了一致共识:地下水超采是引发太原盆地地面沉降的最主要原因。但对这样一个复杂的流固耦合问题仅仅从定性角度研究还远远不够,建立地下水—地面沉降耦合数值模型进行定量研究对太原盆地地下水合理开发利用及防治太原盆地地面沉降有着重要的指导意义。本文应用Terzaghi有效应力原理,研究了地下水流和土体变形耦合的机理,在忽略土体水平形变的基础上,建立了三维地下水流和垂向一维土体变形耦合模型,并进行了模型校正、验证,最终确定了模型参数。最后,利用所建模型对现状开采条件下未来20年太原盆地地下水水位及地面沉降情况进行预测,并提出三种地下水合理开采方案:(1)限采区地下水压采50%。(2)压采的基础上进行地下水回灌。(3)调整地下水开采层位。对三种方案分别建立预测模型进行模拟计算,并对预测结果进行分析,结果三种方案都能减缓地面沉降速率,其中,方案二控沉效果最为明显。
[Abstract]:Taiyuan Basin is located in the central part of Shanxi Province. It is an important coal energy base in China, and is also a typical lack of water resources in China. In recent years, with the development of social economy in this area, groundwater overproduction is becoming more and more serious, which leads to serious land subsidence. Land subsidence is a kind of gentle geological disaster which is common in the world. The harm caused by it is hidden and long-term, which seriously restricts the sustainable development of economy and society. How to effectively prevent and control land subsidence has become a research hotspot. Taiyuan Basin is a typical representative of land subsidence disaster in China. Many qualitative studies have been done and a consensus has been reached that groundwater overproduction is the main cause of ground subsidence in Taiyuan Basin. However, it is far from enough to study such a complex fluid-solid coupling problem from a qualitative perspective. It is of great significance to establish the coupled numerical model of groundwater and ground subsidence for rational exploitation and utilization of groundwater in Taiyuan Basin and to prevent and cure the ground subsidence in Taiyuan Basin. In this paper, the coupling mechanism of groundwater flow and soil deformation is studied by using the Terzaghi effective stress principle. On the basis of ignoring the horizontal deformation of soil, the coupling model of three-dimensional groundwater flow and vertical one-dimensional soil deformation is established, and the model correction is carried out. Finally, the model parameters are determined. Finally, the groundwater level and ground subsidence in Taiyuan Basin in the next 20 years are predicted by using the established model. Three reasonable groundwater exploitation schemes are put forward: (1) groundwater pressure recovery in limited mining area, (2) groundwater recharge on the basis of pressure extraction, and (3) adjustment of groundwater exploitation horizon. The three schemes were simulated and calculated by establishing prediction models, and the predicted results were analyzed. The results show that all three schemes can slow down the land subsidence rate, among which the effect of the second scheme is the most obvious.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.26

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