【摘要】：重慶地區(qū)在城市建設(shè)過程中形成較多緩傾順向泥巖斜坡,其強(qiáng)度低、易風(fēng)化,因其穩(wěn)定性評價指標(biāo)取值不準(zhǔn)確常造成治理工程設(shè)計失誤,發(fā)生斜坡變形和工程投資增加的實例多,損失大。在重慶地區(qū)緩傾順向泥巖斜坡勘察過程中,由于斜坡潛在結(jié)構(gòu)面的復(fù)雜性及泥巖本身的低強(qiáng)度、易風(fēng)化和蠕變等特性,導(dǎo)致緩傾順向泥巖斜坡穩(wěn)定性評判時,勘察人員不能準(zhǔn)確掌控其評價指標(biāo),常常是根據(jù)有限的室內(nèi)試驗結(jié)合工程經(jīng)驗進(jìn)行取值。評判指標(biāo)直接影響斜坡穩(wěn)定性判別結(jié)果,且穩(wěn)定性狀態(tài)對評判指標(biāo)敏感性較強(qiáng)(結(jié)構(gòu)面c、?值),其穩(wěn)定性評判結(jié)果與實際情況有不少偏差,造成部分治理工程的設(shè)計安全儲備較大,工程投資增加。本文針對重慶地區(qū)典型的緩傾順向泥巖斜坡進(jìn)行勘察、設(shè)計資料收集并展開較為全面的現(xiàn)場調(diào)研,通過對勘察、設(shè)計階段提供的抗剪強(qiáng)度參數(shù)分析,研究參數(shù)對已失穩(wěn)緩傾順向泥巖斜坡實際情況的符合程度、參數(shù)折減時的不合理性等,并對不同緩傾順向泥巖斜坡破壞模式進(jìn)行分類研究。其次,通過對泥巖自身力學(xué)特性研究,分析緩傾順向泥巖斜坡不同模式的破壞機(jī)制,并應(yīng)用權(quán)重分析等數(shù)學(xué)分析方法對其穩(wěn)定進(jìn)行判別,與采用規(guī)范方法計算的穩(wěn)定性判別結(jié)果進(jìn)行對比,綜合全面對比分析,提出緩傾順向泥巖斜坡的抗剪強(qiáng)度指標(biāo)折減方法。最后,應(yīng)用有限元分析軟件對不同類型的緩傾順向泥巖斜坡進(jìn)行數(shù)值模擬分析,研究斜坡應(yīng)力場的演變模式和應(yīng)力-應(yīng)變區(qū)域。主要成果如下:(1)重慶地區(qū)泥巖力學(xué)特性:研究了泥巖在降雨、風(fēng)化等外力地質(zhì)條件作用下,強(qiáng)度衰減、大變形、風(fēng)化時效和蠕變等特性。(2)重慶地區(qū)緩傾順向泥巖斜坡結(jié)構(gòu)面抗剪強(qiáng)度指標(biāo)折減系數(shù):依據(jù)搜集的工程實例資料和現(xiàn)場調(diào)研,結(jié)合對泥巖力學(xué)特性的研究認(rèn)識成果,建立了緩傾順向泥巖斜坡坡體泥巖力學(xué)衰減聯(lián)系,依照此聯(lián)系提出較為準(zhǔn)確的結(jié)構(gòu)面抗剪強(qiáng)度指標(biāo)折減系數(shù)。(3)分類別的重慶地區(qū)緩傾順向泥巖斜坡穩(wěn)定性評判結(jié)構(gòu)面抗剪強(qiáng)度指標(biāo)值:對重慶地區(qū)緩傾順向泥巖斜坡不同破壞模式進(jìn)行分類、分階段研究,最后得到每種破壞模式各個階段的結(jié)構(gòu)面抗剪指標(biāo),進(jìn)而確定其穩(wěn)定性狀態(tài),形成圖表。(4)分類別的緩傾順向泥巖斜坡應(yīng)力場的演變模式、應(yīng)變區(qū)域圖集。
[Abstract]:In the process of urban construction in Chongqing area, there are more gently inclined forward mudstone slopes, which are low in strength and easy to weathering, because of the inaccuracy of the evaluation index of its stability, which often results in the failure of the design of the treatment project. There are many examples of slope deformation and project investment increase, and the loss is large. In the process of the investigation of the slope of the gentle downward direction mudstone in Chongqing area, due to the complexity of the potential structural surface of the slope and the characteristics of low strength, easy weathering and creep of the mudstone itself, the stability of the slope of the gentle downward direction of mudstone is evaluated. The surveyor can not control the evaluation index accurately, and usually takes the value according to the limited indoor test and engineering experience. The evaluation index has direct influence on the judging result of slope stability, and the stability state is more sensitive to the evaluation index. There are many deviations between the results of stability evaluation and the actual situation, which results in a large design safety reserve and an increase in project investment in some treatment projects. In this paper, the typical sloping mudstone slopes in Chongqing are surveyed, the design data are collected and a comprehensive field investigation is carried out. Through the analysis of the shear strength parameters provided in the survey and design stage, The degree of conformity of the parameters to the actual condition of the slope of the progressive mudstone slope and the irrationality of the parameter reduction are studied, and the failure modes of the slope are classified and studied. Secondly, through the study of the mechanical characteristics of mudstone itself, the failure mechanism of different models of gently inclined forward mudstone slope is analyzed, and the stability of mudstone slope is judged by using the mathematical analysis method such as weight analysis. Compared with the stability discriminating results calculated by the standard method and comprehensive comparison and analysis, a reduction method of shear strength index of the slope with gentle forward direction mudstone is put forward. Finally, the numerical simulation of different types of gentle forward mudstone slopes is carried out by using finite element analysis software, and the evolution model and stress-strain region of slope stress field are studied. The main results are as follows: (1) the mechanical properties of mudstone in Chongqing area: the strength attenuation and large deformation of mudstone under the action of external forces such as rainfall and weathering are studied. Characteristics of weathering aging and creep. (2) the shear strength index reduction coefficient of the structural plane of gently inclined downstream mudstone slope in Chongqing area: based on the collected engineering data and field investigation, combined with the results of the study on the mechanical properties of mudstone, The mechanical attenuation relation of mudstone on slope of gently inclined mudstone slope is established. According to this relation, a more accurate shear strength index reduction coefficient of the structural plane is put forward. (3) the index value of shear strength of the structural plane for the evaluation of the stability of the gently inclined forward mudstone slope in Chongqing area: the value of the shear strength index of the structural plane in the Chongqing area. Different failure modes of mudstone slopes are classified, Finally, the shear resistance index of each stage of each failure mode is obtained, and the stability state is determined. (4) the evolution model of the stress field and the strain region atlas of the gentle downward slope of mudstone.
【學(xué)位授予單位】：重慶交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU45

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