本文關(guān)鍵詞： 地下水抽取 地面沉降 第四紀(jì)沉積層 分布式光纖監(jiān)測 壓縮度　出處：《工程地質(zhì)學(xué)報》2016年01期 　論文類型：期刊論文

【摘要】：蘇州地區(qū)廣泛分布松散第四紀(jì)沉積物,大量抽取地下水導(dǎo)致了蘇州大范圍的地面沉降,嚴(yán)重影響了該區(qū)經(jīng)濟發(fā)展。本文在蘇州盛澤200m鉆孔內(nèi)安裝了分布式感測光纖,采用BOTDR及FBG等分布式光纖感測技術(shù)(DFOS),對第四紀(jì)沉積層壓縮及地面沉降進(jìn)行了長期的監(jiān)測分析。分析結(jié)果表明:蘇州盛澤地區(qū)第四紀(jì)土層可分為3個含水層(Af)及4個弱透水層(Ad),現(xiàn)階段含水層壓縮已不明顯,主要壓縮層為與抽水含水層相鄰的兩個隔水層,且與抽水含水層距離越近的部位壓縮越明顯;第四紀(jì)沉積層的變形與抽水含水層孔隙水壓變化基本一致,呈現(xiàn)出夏季壓縮,冬季略回彈的趨勢,并且存在滯后現(xiàn)象;定義壓縮度為各層累計壓縮量與其自身厚度的比值,即每米壓縮量。各土層沉降趨勢可用壓縮度判斷,對于黏土隔水層沉降程度Ad2Ad3Ad4Ad1,對于含水砂層,Af2為主要變形層,Af1及Af3變形基本穩(wěn)定。DFOS技術(shù)為研究地面沉降機理,評價土層壓縮變形潛力提供了十分先進(jìn)的監(jiān)測手段。
[Abstract]:The loose Quaternary sediments were widely distributed in Suzhou area, and a large amount of groundwater extraction resulted in a large area of land subsidence in Suzhou, which seriously affected the economic development of the region. In this paper, distributed sensing fiber was installed in the 200 m borehole of Shengze, Suzhou. Using distributed optical fiber sensing techniques, such as BOTDR and FBG, the long-term monitoring and analysis of Quaternary sedimentary layer compression and land subsidence are carried out. The results show that the Quaternary soil layer in Shengze area of Suzhou can be divided into 3 aquifers and 4. At this stage, the compression of the aquifer is not obvious. The main compression layer is the two water-isolated layers adjacent to the pumping aquifer, and the more close to the pumping aquifer, the more obvious the compression is, and the deformation of the Quaternary sedimentary layer is basically consistent with the variation of pore water pressure of the pumping aquifer, showing the summer compression. The tendency of springback in winter is slight, and there is lag phenomenon, the compression degree is defined as the ratio of the accumulative compression amount of each layer to its own thickness, that is, the amount of compression per meter, and the settlement trend of each soil layer can be judged by the compression degree. For the settlement degree Ad2Ad3Ad4Ad1 of the clay barrier, for the main deformed layer (Af1) of the water-bearing sand bed, and for the stable deformation of Af3, it provides a very advanced monitoring method for studying the mechanism of land subsidence and evaluating the compressive deformation potential of the soil layer.
【作者單位】： 南京大學(xué)地球科學(xué)與工程學(xué)院;南京大學(xué)地理與海洋科學(xué)學(xué)院;中國地質(zhì)調(diào)查局南京地質(zhì)調(diào)查中心;
【基金】：國家自然科學(xué)基金重點項目(No.41230636);國家自然科學(xué)基金項目(No.41372265) 地質(zhì)礦產(chǎn)調(diào)查評價專項(1212011220002)資助
【分類號】：P642.26;P534.63
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本文編號：1537292