本文選題：地面沉降 + 地下水��； 參考：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文

【摘要】：地面沉降是一類因人類工程活動引發(fā)或由自然因素驅(qū)使,以新生代以來地層中松散堆積土體的固結(jié)為主,發(fā)生的較大規(guī)模區(qū)域內(nèi)地面高程降低的地質(zhì)現(xiàn)象,亦是一類由水土相互作用下使得土體結(jié)構(gòu)強度緩慢遭受破壞的地質(zhì)災(zāi)害。華北平原地區(qū)自20世紀(jì)60年代以來,因長期過量開采地下水,形成了大量地下水位降深漏斗,引發(fā)了一系列地面沉降問題,滄州位于華北平原腹地,截止2015年其累計沉降量大于800mm的區(qū)域已超過3200km2,中心累計沉降量已超過2500mm。隨著近年來京津冀一體化建設(shè)的加快,各類環(huán)境問題凸顯,滄州市在2007~2010年采取一定管制開采地下水后,其中心沉降速率雖趨于緩和,但其沉降面積仍以較快速度向城鎮(zhèn)發(fā)展。為更好地防控與監(jiān)測地面沉降,通過數(shù)值模擬的方法重現(xiàn)其發(fā)展歷史,分析其發(fā)展現(xiàn)狀,成為近年來滄州地面沉降研究的主要任務(wù)。本文通過已有的監(jiān)測記錄結(jié)合前人研究經(jīng)驗,首先對滄州地區(qū)不同含水層的變形規(guī)律進(jìn)行了討論,通過分析土樣物理力學(xué)性質(zhì)隨埋深的變化,掌握含水層的變形特征隨埋深的規(guī)律;通過分析各類壓縮實驗結(jié)果,驗證由過量開采地下水引發(fā)主要沉降的地層范圍,評估由地下水動態(tài)變化對含水層沉降特征的影響,推算了含水層彈性釋水參數(shù)、非彈性釋水參數(shù)以及垂向滲透系數(shù);其次結(jié)合研究區(qū)域的地質(zhì)條件,應(yīng)用GMS10.0中MODFLOW功能區(qū)塊建立了應(yīng)力期自2005年12月到2012年12月的滄州地區(qū)三維地下水流模型,利用SUB模塊將其改進(jìn)為一維固結(jié)情形下的水土耦合模型,并求解。根據(jù)2011-2012年地面沉降水準(zhǔn)測量值,通過一系列擬合校正,反復(fù)調(diào)整參數(shù)、重新概化沉降土層建立了滄州地面沉降研究模型。最終,通過本次研究分析的滄州地區(qū)地面沉降特征,結(jié)合各類土工實驗的結(jié)果,通過模擬軟件,對含水層發(fā)生地面沉降的層位進(jìn)行了滯后釋水與非滯后釋水的概化,建立起了較為復(fù)合實際情況的地面沉降模型,為今后該區(qū)域建立更為精確的地面沉降預(yù)測模型提供了參考思路。
[Abstract]:Land subsidence is a kind of geological phenomenon which is caused by human engineering activities or driven by natural factors and is dominated by the consolidation of loosely accumulated soil in the strata since the Cenozoic. It is also a kind of geological hazard that soil structure strength is destroyed slowly by soil and water interaction. Since the 1960s, a large number of groundwater funnels have been formed in the North China Plain, and Cangzhou is located in the hinterland of the North China Plain. Up to 2015, the accumulative settlement amount was more than 3200km2 in the area larger than 800mm, and more than 2500mm in the center. With the acceleration of the integrated construction of Beijing, Tianjin and Hebei in recent years, all kinds of environmental problems have been highlighted. After Cangzhou adopted certain regulation to exploit groundwater from 2007 to 2010, the central subsidence rate of Cangzhou City tended to ease, but its subsidence area still developed to towns at a relatively fast speed. In order to better prevent and control and monitor land subsidence, it is the main task of Cangzhou land subsidence research in recent years to reproduce its development history and analyze its development status by numerical simulation. In this paper, based on the existing monitoring records and previous research experience, the deformation law of different aquifers in Cangzhou area is discussed, and the variation of physical and mechanical properties of soil samples with buried depth is analyzed. By analyzing the results of various compression experiments, the author verifies the stratigraphic range of the main subsidence caused by over-exploitation of groundwater, and evaluates the influence of the dynamic change of groundwater on the characteristics of aquifer settlement. The elastic water release parameters, the inelastic water release parameters and the vertical permeability coefficient of the aquifer are calculated. Secondly, the geological conditions of the studied area are considered. The three-dimensional groundwater flow model of Cangzhou region with stress period from December 2005 to December 2012 was established by using MODFLOW functional block in GMS10.0. The model was improved into a soil and water coupling model under one-dimensional consolidation by using SUB module and solved. According to the measured values of land subsidence leveling in 2011-2012, the study model of Cangzhou land subsidence is established through a series of fitting and correction, and the parameters are adjusted repeatedly. Finally, through the analysis of the characteristics of land subsidence in Cangzhou area, combined with the results of various geotechnical experiments, and through the simulation software, the ground subsidence of the aquifer is generalized by the delayed and undelayed water release. A more complex ground subsidence model is established, which provides a reference for the establishment of a more accurate land subsidence prediction model in the region in the future.
【學(xué)位授予單位】：中國地質(zhì)大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：P642.26;P641
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本文編號：1863591