本文選題：土層參數(shù)　切入點：反分析　出處：《昆明理工大學》2015年碩士論文

【摘要】：土層參數(shù)是巖土工程設計過程中的重要指標,一般通過室內試驗獲得,由于土層的自然變異性、試驗條件、試驗方法等方面的原因,試驗結果往往具有離散性,與真實值有一定差異。再者,如果工程施工方法不同,即使是同一種土體,其土層參數(shù)也會存在差異。因此,需要采用適當?shù)姆椒ê侠淼拇_定土層參數(shù)。結合已有監(jiān)測數(shù)據(jù),通過反分析手段獲得土層參數(shù),然后用反分析得到的參數(shù)進行正分析,從而可以及時更新數(shù)據(jù)、指導后期設計施工或指導類似工程設計。本文從反分析方法及其應用方面展開研究工作,如下：(1)針對目前反分析方法存在的問題,提出了一種基于非參數(shù)回歸的土層參數(shù)反分析算法。將不同工況的同一實測目標作為約束條件,考慮實測目標量測的誤差,選定容差ε,從而得到目標實測值的容差范圍,然后確定待反分析土層參數(shù)的初始范圍,結合均勻試驗和非參數(shù)回歸方法建立土層參數(shù)與實測目標之間的響應面,按照工況枚舉處大量參數(shù)樣本,利用響應面插值得到大量目標計算值,逐一對比目標的計算值和實測值,篩分出在容差范圍內與目標實測值接近的目標計算值所對應的土層參數(shù)數(shù)據(jù)樣本,并把數(shù)據(jù)樣本的統(tǒng)計范圍作為目標實測值在一定容差范圍內對應的土層參數(shù)實際取值區(qū)間。(2)反分析算法在基坑工程中的應用。選擇鋼支撐力和樁身水平位移作為實測目標,利用反分析算法對基坑剖面支護樁所在深度范圍內土層的抗剪強度指標c、φ值進行反分析,得到土層參數(shù)的取值區(qū)間,并進行了驗證。(3)反分析算法在盾構隧道工程中的應用。選擇地面沉降作為實測目標,利用反分析算法對盾構隧道開挖影響范圍內土層的抗剪強度指標c、φ值進行反分析,得到土層參數(shù)的取值區(qū)間,并利用反分析結果預測臨近將要開挖斷面的地面沉降,與實測值作對比,結果較為接近。通過兩個工程實例的應用,表明了本文提出的反分析算法是可行的,并且是一種通用算法,該算法考慮了目標實測值量測的誤差和施工工況的影響,可以選擇多個實測目標作為約束條件綜合分析多個參數(shù),提高了分析效率,可以用于指導設計施工,為巖土工程中土層參數(shù)反分析提供了一條有效途徑。
[Abstract]:Soil layer parameter is an important index in the process of geotechnical engineering design. Generally, it is obtained by indoor test. Due to the natural variability of soil layer, test conditions, test method and other reasons, the test results are often discrete. Moreover, if the engineering construction method is different, even if the soil is the same soil, the soil layer parameters will be different. Therefore, it is necessary to adopt appropriate method to determine the soil layer parameters reasonably, combined with the existing monitoring data, The parameters of soil layer are obtained by means of back analysis, and then the parameters obtained by back analysis are used to carry out positive analysis, so that the data can be updated in time. To guide the design and construction of later stage or to guide similar engineering design. In this paper, the research work is carried out from the aspects of back-analysis method and its application, as follows: (1) in view of the problems existing in the present back-analysis method, A non-parametric regression based back-analysis algorithm for soil layer parameters is proposed. Taking the same measured target under different working conditions as the constraint condition and considering the error of the measured target measurement, the tolerance 蔚 is selected, and the tolerance range of the target measured value is obtained. Then the initial range of soil parameters is determined, and the response surface between soil parameters and measured targets is established by combining uniform test and non-parametric regression method, and a large number of parameter samples are obtained according to the enumeration of working conditions. A large number of target calculated values are obtained by using response surface interpolation. The calculated and measured values of the target are compared one by one, and the soil layer parameter data samples corresponding to the calculated value of the target in the tolerance range are sifted out. The statistical range of the data sample is taken as the range of actual values of soil parameters in a certain tolerance range. The application of inverse analysis algorithm in foundation pit engineering is discussed. The steel bearing force and the horizontal displacement of pile body are chosen as the measured targets. By using the inverse analysis algorithm, the shear strength indexes c and 蠁 of the soil layer in the depth range of the foundation pit profile supporting pile are back analyzed, and the interval of the soil layer parameters is obtained. The application of the back-analysis algorithm in shield tunnel engineering is verified. The anti-analysis algorithm is used to analyze the shear strength index (c, 蠁) of the soil layer in the influence area of shield tunnel excavation by selecting the ground settlement as the measured target. The value interval of soil parameters is obtained, and the ground subsidence near the excavation section is predicted by using the result of back analysis. The results are close to those of the measured values. Through the application of two engineering examples, The results show that the proposed inverse analysis algorithm is feasible, and it is a general algorithm, which takes into account the error of target measured value and the effect of construction condition. A number of measured targets can be selected as constraint conditions for comprehensive analysis of multiple parameters, which improves the efficiency of analysis, can be used to guide design and construction, and provides an effective way for back analysis of soil parameters in geotechnical engineering.
【學位授予單位】：昆明理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU43

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本文編號：1687234