發(fā)布時間：2018-02-10 10:24

  本文關鍵詞： 滄州 地面沉降 地下水開采 模擬預測 危害性評價　出處：《中國礦業(yè)大學(北京)》2017年博士論文　論文類型：學位論文

【摘要】：隨著滄州地區(qū)經濟社會的快速發(fā)展,深層地下水、地熱、石油、天然氣等地下資源的不斷開發(fā),尤其是深層地下水的長期過度開采,造成地下水位逐年下降,呈漏斗趨勢包圍全區(qū),進而導致地面不均勻沉降現象的產生。隨著時間的推移,地面沉降發(fā)展迅速,目前已覆蓋了整個滄州地區(qū),并呈現出沉降量大、下沉快、影響范圍廣等特點,使滄州成為整個華北地區(qū)甚至是全中國范圍內發(fā)生嚴重地面沉降災害的城市之一,直接制約著滄州地區(qū)經濟、社會可持續(xù)發(fā)展。本文以整個滄州地區(qū)為研究對象,搜集整理了研究區(qū)地質環(huán)境相關資料,全面分析滄州地區(qū)地面沉降發(fā)生地質背景,鉆孔資料,監(jiān)測數據,地下水開采狀況以及地面沉降發(fā)展現狀,從引發(fā)滄州地區(qū)地面沉降的因素及其相關規(guī)律進行研究,并建立地面沉降預測模型,對不同地下水開采模式下地面沉降的發(fā)展趨勢進行預測,并以預測結果為基礎,對滄州地區(qū)地面沉降進行危害性評價。主要內容如下:(1)借助ARCGIS軟件空間分析方法與InSAR監(jiān)測技術從地面沉降的沉降速率變化和累計沉降量分布兩方面開展工作,對滄州地區(qū)地面沉降發(fā)展過程及現狀進行了歸納分析。研究發(fā)現,自70年代區(qū)內出現地面沉降以來,隨著地下水開采強度不斷加大,地面沉降現象逐漸嚴重,由唯一的滄州市區(qū)沉降中心發(fā)展成為以任丘、肅寧、滄州市區(qū)、青縣等多個城區(qū)多中心的復合沉降區(qū),其中滄州市區(qū)沉降中心累計沉降量達到2600m,隨著近幾年來滄州城區(qū)地下水開采的限制,滄州市區(qū)沉降中心地面沉降發(fā)展得到緩解,年沉降速率降低到10.84mm/a,但周邊縣市深層地下水開采量的增加,區(qū)內整體沉降又有反彈的趨勢。整個沉降區(qū)呈現出城市較郊區(qū)發(fā)展嚴重,城鎮(zhèn)居住區(qū)較農業(yè)種植區(qū)嚴重、西部較東部地區(qū)嚴重、經濟發(fā)達較不發(fā)達地區(qū)嚴重等特點。主要原因為城區(qū)發(fā)展需要開采大量地下水,尤其是經濟發(fā)達城市對地下水需求量更甚,而地下水的開采對地面沉降的發(fā)展有重要的影響作用。據近幾年InSAR監(jiān)測圖來看,2014年與2013年相比:總體呈現加快的趨勢,主要表現為各城區(qū)地面沉降速率增加10~20mm/a。2015年與2014年對比,總體又趨于平緩,主要原因為降雨量不均衡性導致2014年地下水開采量大,2015年開采量小,這又從速率方面反映出地下水開采與地面沉降之間聯系緊密。通過對各年地面速率進行疊加,展示了近年來地面沉降的新趨勢,最后根據地面沉降速率將地面沉降區(qū)劃分為四個不同沉降區(qū),展示地面沉降最新發(fā)展態(tài)勢。(2)借助太沙基(Terzaghi)有效應力理論并結合滄州地區(qū)地質環(huán)境特點對地面沉降成因機理進行闡述,同時對影響地面沉降的相關因素進行分析,確定研究區(qū)地面沉降發(fā)生實質上是其內、外因共同作用的水文地質和工程地質現象。其內在因素為地層中存在黏性土層即可壓縮體,外部因素為地下水的大量開采。(3)對引起地面沉降發(fā)生的外部因素開展研究,通過ARCGIS軟件的空間分析功能,以滄州地區(qū)自身的地質環(huán)境條件為基礎,從地下水開采與地面沉降的時空演變、地下水開采量與地面沉降量對應關系、地下水水位與地面沉降速率相關性分析等方面,全面系統(tǒng)的對滄州地區(qū)地下水開采對地面沉降影響規(guī)律進行深入分析,結果表明滄州地區(qū)地面沉降與地下水開采密切相關,地下水開采的各階段與地面沉降發(fā)展的各階段相對應,地面沉降與地下水水位漏斗在空間展布關系與發(fā)展趨勢上存在一致性,地面沉降總體積約占地下水開采量的一半,且隨著開采時間的增加,比例逐漸降低,地面沉降速率與地下水水位成正相關性,隨著地下水位的變化而變化,部分地層存在滯后性,滯后期為一個月左右。從長年變化來看,地下水位與累計地面沉降量之間存在線性回歸關系,并根據回歸曲線得出在滄州地區(qū),地下水水位降深存在一個40m的水位警戒閾值,若水位降深大于該值,則累計沉降量會隨著水位降深的增加呈加速度上升。而70m水位降深為限制開采閾值,超過這一水位,地面沉降將會成直線上升趨勢。(4)在充分分析已有監(jiān)測資料以及鉆探資料的基礎上,結合實際的地質條件以及地質構造,從引起地面沉降發(fā)生的內部因素出發(fā),將滄州地區(qū)地面沉降的壓縮層組劃分為三個壓縮層組,并將地面沉降區(qū)分布圖與壓縮層厚度圖進行疊加分析,從而得出,沉降區(qū)與可壓縮層存在對應關系,沉降嚴重地區(qū)往往是壓縮層較厚的地區(qū)。通過對地面沉降分層標監(jiān)測數據進行處理,從而確定第二壓縮層組沉降量貢獻率約占總地層壓縮貢獻率的70%左右,為地面沉降主要壓縮貢獻層,主要包括第Ⅲ含水層以及其中的巨厚的黏性土層。(5)對目前已有地面沉降模型理論進行總結分析,并針對滄州地區(qū)自身特點選擇地下水-地面沉降模型理論構建滄州地區(qū)地面沉降預測模型。(6)在深入分析滄州地區(qū)水文地質和工程地質條件的基礎上,對其地下水流狀態(tài)、含水層結構性質、邊界條件、參數性質等一系列條件因素進行綜合概化,對研究區(qū)源匯項進行了處理,建立該地區(qū)水文地質概念模型并對其進行數學概化,獲得地下水數學模型,通過GMS軟件構建地下水流數值模型,以2014年12月實測的淺層和深層地下水水位作為模型的初始水位,對2015年1月~2015年12月每個月的地下水流場進行數值模擬,并借助各月實測水位數據對模型反復校正識別,得到合理的水文地質參數。使模型能夠正確模擬地下水流情況。(7)依據太沙基(Terzaghi)固結理論,對土體變形原理進行數學概化,針對滄州地區(qū)地面沉降存在滯后性的特點,將沉降區(qū)內黏性土層劃分為滯后性黏土層和非滯后性黏土層,并分別對其釋水機理進行數學描述,將土體變形數學模型與地下水數學模型相結合,并借助SUB模塊構建地下水-地面沉降數值模型,對滄州地區(qū)地面沉降過程進行數值模擬,以2015年沉降監(jiān)測數據對模型參數進行修正,使模型能夠正確模擬地面沉降發(fā)展。(8)本章首先以2015年現狀地下水開采數據為基礎,對滄州地區(qū)地下水與地面沉降發(fā)展趨勢進行預測,通過預測結果可以看出,到2020年,滄州地區(qū)地下水主要開采層水位降幅較大,最大水位降幅為15m,該階段發(fā)展嚴重區(qū)為任丘市、肅寧縣、獻縣、滄縣、青縣、南皮縣、東光縣7個縣市。各區(qū)最大地面沉降量分別為231mm、214.5mm、163mm、216mm、246.8mm、241.6mm。接著以《滄州市地下水取水總量年度考核指標(2016~2020年)》為依據,按2016~2020年限定開采量為輸入數據,對滄州地區(qū)地下水與地面沉降發(fā)展趨勢進行預測,通過預測結果可以看出,隨時間推移,地下水位下降逐漸減小,到2020年,地下水位得到回升,最大上升5m,地面沉降也得到了控制,最大沉降量為143.2mm,遠小于維持現狀開采下的地面沉降量。表明該減采方案效果明顯,使地面沉降的發(fā)展得到了控制。(9)針對地面沉降災害所具有的自然屬性與社會屬性,構建基于“三圖法”的滄州地區(qū)地面沉降危害性評價模型。首先以考核指標開采條件下2020年地面沉降預測結果為基礎,對滄州地區(qū)地面沉降災害的自然屬性進行分析研究,構建地面沉降危險性評價體系,通過地理信息系統(tǒng)(ARCGIS)與模糊層次評價法,對地面沉降危險性進行分區(qū)評價,將滄州地區(qū)按地面沉降危險性程度不同劃分為大、中、小三個區(qū),并繪制地面沉降危險性分區(qū)圖(第一圖),接著依據地面沉降區(qū)內社會經濟、人口、城市發(fā)展狀況,構建地面沉降易損性評價體系,結合地理信息系統(tǒng)(ARCGIS)對地面沉降災害發(fā)生的社會屬性進行定量研究,對承災體易損性進行評價,將滄州地區(qū)按地面沉降易損性程度不同劃分為大、中、小三個區(qū),并繪制地面沉降易損性分區(qū)圖(第二圖)。通過地理信息系統(tǒng)(ARCGIS)的空間分析技術,將地面沉降危險性分區(qū)圖與易損性分區(qū)圖進行疊加處理,繪制地面沉降危害性評價分區(qū)圖(第三圖),利用“三圖法”評價方法,完成對滄州地區(qū)地面沉降的危害性評價工作。為未來滄州地區(qū)城市發(fā)展、規(guī)劃制定提供了科學依據。
[Abstract]:With the rapid development of economy and society, the Cangzhou area of deep groundwater, geothermal, oil, natural gas and other underground resources development, especially the deep groundwater over exploitation of groundwater caused by long-term, decreased year by year, and the region surrounded by a funnel trend, leading to the phenomenon of uneven settlement of the ground. With the passage of time, the development of land subsidence quickly, now covers the whole Cangzhou area, and showing a large settlement, sinking fast, affecting a wide range of features, make Cangzhou become the North China region and even the city is one of the serious land subsidence disaster China full range, directly restricts the sustainable development of social economy in Cangzhou, the whole Cangzhou area. The research object, collecting the geological environment of the study area related data, a comprehensive analysis of land subsidence in Cangzhou region geological background, borehole data, monitoring data, The mining condition of groundwater and land subsidence situation, study from the causes of land subsidence in Cangzhou region and related laws, and establish prediction model of land subsidence, to predict the development trend of land subsidence in different groundwater exploitation mode, and the prediction results based on hazard evaluation of land subsidence in Cangzhou region. The main content are as follows: (1) by using the software of ARCGIS spatial analysis of sedimentation rate changes from the ground settlement method and InSAR monitoring technology and the total settlement distribution of the two aspects of the work, this paper analyzed the land subsidence in Cangzhou development process and current situation. The study found that since 70s in the area of land subsidence, groundwater exploitation intensity with increasing gradually, the ground subsidence phenomenon serious, only by the Cangzhou city center become the settlement in Renqiu, Suning, Cangzhou City, Qingxian County Composite settlement district and other districts of the city of Cangzhou multi center, settlement center settlement volume reached 2600m, with the limit of Cangzhou city groundwater exploitation in recent years, Cangzhou urban settlement center for land subsidence development eased, annual deposition rate reduced to 10.84mm/a, but the increase of the surrounding counties of deep groundwater resources, the region in general settlement and rebound trend. The settlement area presents City suburb development seriously, urban residential district is a serious agricultural area, West than in the East region is serious, the economically developed less developed areas is serious. The main reason for the urban development needs large exploitation of groundwater, especially in economically developed city of groundwater demand even more however, the development of groundwater exploitation on land subsidence has important effect in recent years. According to the InSAR monitoring chart, in 2014 compared with 2013 shows: To speed up the trend, mainly to increase 10~20mm/a.2015 compared with 2014 settlement rate of the city ground, overall and tends to slow, the main reason for the imbalance of the rainfall in 2014 2015 a large amount of groundwater mining, mining quantity is small, this reflects from a rate of groundwater exploitation and land subsidence in close relation between through the superposition of. The ground rate shows a new trend in recent years, ground subsidence, ground subsidence rate according to the land subsidence area is divided into four different areas of settlement, the latest development trend of ground settlement show. (2) (Terzaghi) by Terzaghi effective stress theory and combining with the geological environment characteristics of Cangzhou formation mechanism on the ground the settlement is expounded, and the related influencing factors of ground subsidence are analyzed, the research area of land subsidence is essentially the interaction of external, hydrological The geological and engineering geological phenomena. The internal factors for the existence of cohesive soil can compress body formation, external factors for a large number of groundwater. (3) caused by external factors of land subsidence research, through the function of space analysis of ARCGIS software in Cangzhou area's geological environmental conditions based on spatial and temporal evolution of settlement from the ground and groundwater exploitation, groundwater exploitation and land subsidence correspondence, sedimentation rate correlation analysis of groundwater level and ground, systematically analyzing the influence of ground subsidence depth analysis of mining groundwater in Cangzhou area, results show that the groundwater exploitation is closely related with the ground settlement in Cangzhou area, the stage of development of the corresponding settlement each stage of ground and groundwater exploitation, there are the development trend of land subsidence and groundwater funnel in spatial distribution with 涓，

本文編號：1500299