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  本文選題：懸掛式止水帷幕　切入點(diǎn)：深基坑降水　出處：《遼寧科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著經(jīng)濟(jì)建設(shè)的高速發(fā)展,深基坑工程應(yīng)運(yùn)而生,其中不乏大型深基坑。在深基坑設(shè)計及施工中,設(shè)置好止水帷幕是不可或缺的一環(huán)。絕大多數(shù)的止水帷幕設(shè)計都是為了獲得最好的止水效果,而很少定量的研究止水帷幕作用下基坑的滲流特性。本文從滲流理論出發(fā),對比分析了ANSYS軟件中熱分析模塊原理和滲流基本理論的相似性,利用軟件對基坑穩(wěn)定滲流過程進(jìn)行模擬,通過對比多種工況,用一系列數(shù)據(jù)分析止水帷幕對深基坑滲流場的影響,探討止水帷幕在不同插入深度的工況下對基坑滲流場的影響。止水帷幕的深度不同,直接影響的就是滲流路徑不同,在插入不透水層中的深度越大,滲流路徑就越大,相對應(yīng)的滲流場水頭分布和水力坡降分布就會發(fā)生變化,而基坑以下水壓過大會影響基底安全,發(fā)生突涌等危害,基底最大水力坡降值也會影響基坑的安全,本文通過模擬不同幕墻深度時基坑水頭值變化分布及基底最大水力坡降值的變化,找出幕墻的關(guān)鍵深度。在單一均質(zhì)土層中,在幕墻插入深度近似達(dá)到所在不透水層深度的25%時,基底以下水頭值均達(dá)到最大;當(dāng)插入深度達(dá)到不透水層的61%時,水頭值與無止水帷幕時的水頭值一致,當(dāng)插入深入達(dá)到61%-99%時,基坑內(nèi)所有水頭值均小于無幕墻時的水頭值,并依然在下降,才能真正起到降低水頭的作用;止水帷幕深度的增加,對降低基坑內(nèi)外水力坡降的作用非常明顯,在幕墻深度增加到接近不透水層時,水力坡降的降低量能達(dá)到初始值的90%以上,效果顯著,但它的降低值是先大幅度降低,在插入深度達(dá)到不透水的34%左右時,降低幅度變小,趨于平緩。結(jié)合北京華聯(lián)深基坑的工程實(shí)例,模擬研究發(fā)現(xiàn)復(fù)雜土層中也存在與單一均質(zhì)土層中相似的規(guī)律,證明了其現(xiàn)實(shí)存在性,也間接驗(yàn)證了ANSYS熱分析模塊在解決滲流問題上的可行性。
[Abstract]:With the rapid development of economic construction, deep foundation pit engineering emerges as the times require, among which there is no lack of large deep foundation pit. In the design and construction of deep foundation pit, It is indispensable to set up the waterproof curtain. Most of the watertight curtain design is to obtain the best sealing effect, but few quantitative research on the seepage characteristics of the foundation pit under the action of the waterproof curtain. This paper starts from the seepage theory. The similarity between the principle of thermal analysis module and the basic theory of seepage in ANSYS software is compared and the steady seepage process of foundation pit is simulated by software. A series of data are used to analyze the influence of the waterproof curtain on the seepage field of deep foundation pit, and the influence of the waterproof curtain on the seepage field of the deep foundation pit under different conditions of insertion depth is discussed. The greater the depth in the impermeable layer is, the larger the seepage path will be, and the corresponding seepage field water head distribution and hydraulic gradient distribution will change, and the water pressure below the foundation pit will affect the safety of the basement, causing sudden surge, and so on. The maximum hydraulic slope value of the base will also affect the safety of the foundation pit. In this paper, the critical depth of the curtain wall is found by simulating the variation distribution of the water head value of the foundation pit and the maximum hydraulic gradient value of the base under different curtain wall depths. When the insertion depth of the curtain wall reaches approximately 25 of the depth of the impervious layer, the water head value below the basement reaches the maximum; when the insertion depth reaches 61 percent of the impervious layer, the water head value is the same as the water head value when the impervious curtain is not in place. When the penetration depth reaches 61- 99%, all the water head values in the foundation pit are lower than those without curtain wall, and they are still decreasing. When the depth of curtain wall increases to close to impermeable layer, the decrease of hydraulic slope can reach more than 90% of the initial value, and the effect is remarkable. When the insertion depth reaches about 34% of impermeable depth, the decrease becomes smaller and tends to be gentle. Combined with the engineering example of deep foundation pit in Beijing Hualian, it is found that there are similar laws in the complex soil layer and in the single homogeneous soil layer. The feasibility of ANSYS thermal analysis module in solving seepage problem is proved.
【學(xué)位授予單位】：遼寧科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU463

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相關(guān)期刊論文 前10條

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本文編號：1645891