【摘要】：研究區(qū)位于攀枝花機場12#滑坡東側,場區(qū)基巖主要為三疊系寶頂組泥巖段,以炭質泥巖為主,夾砂巖、粉砂質泥巖。12#滑坡及下方易家坪老滑坡下伏基巖上,絕大部分分布有泥巖,填筑料因取自寶頂組泥巖段,含大量的泥巖碎塊碎屑。顯然,攀枝花機場10.3填筑體失穩(wěn)及老滑坡復活都與泥巖的軟化有關。因此,本文針對該地區(qū)泥巖遇水軟化的特性開展一系列試驗研究,并得出以下幾點認識:(1)泥巖初始成分及結構是泥巖(塊)、泥巖結構面遇水軟化的基礎。研究區(qū)泥巖主要由粘土礦物、原生礦物、簡單鹽類、碳質組成。其中,粘土礦物含量占50~95%,原生礦物占4%~35%;簡單鹽類中大多數(shù)為可溶鹽。碳質含量占1%~10%,與粘土礦物呈互染狀,將削弱粘土礦物顆粒之間的聯(lián)結。從微觀結構上,粘土礦物呈隱晶-微晶質集合體、平行堆疊結構,粘土礦物與原生礦物顆粒之間為固體鹽類膠結。以上初始成分結構,決定了研究區(qū)泥巖的天然強度不高(單軸抗壓強度≈10MPa),水穩(wěn)性差、軟化性強。(2)采用純水浸泡試驗表明:(1)研究區(qū)泥巖(塊)含水率、孔隙率在飽水過程中均呈現(xiàn)持續(xù)上升、單軸抗壓強度及抗剪強度則呈持續(xù)衰減趨勢;飽水30天后,泥巖含水率、孔隙率分別增長122.77%、142.72%;單軸抗壓強度下降81%,c、f值分別減小67.86%和53.12%;(2)泥巖結構面物理力學性質的變化趨勢大體上同泥巖(塊)的變化趨勢,但它與水的作用更劇烈,軟化過程更快,其抗剪強度指標飽水10天后就開始趨于穩(wěn)定。飽水30天后,含水率、孔隙率分別增長166.67%、195.97%,c、f值分別減小63.27%和41.67%。(3)泥巖的浸潤具有明顯的各項異性特征。無應力狀態(tài)下,浸潤方向平行層理面時含水率、孔隙率及浸潤深度上升速率明顯比垂直層理面組快。在不同剪應力水平下,沿剪切(潛在破壞)面方向的浸潤深度、上下試塊的含水率、孔隙率均隨剪應力水平增加而增大;剪切面平行層理時的浸潤深度、含水率、孔隙率的增長要大于垂直層面剪切的情況,且在低應力水平兩者的差異較大,在較高應力水平兩者差異較小。(4)地下水與應力作用是導致泥巖軟化的主要外部因素。采用研究區(qū)地下水作浸泡液,泥巖的化學成分的溶解與析出受到一定程度的抑制,泥巖力學性狀的軟化程度不及純水浸泡液的情況。此外,在一定的應力作用下,不僅會直接導致泥巖礦物顆粒之間的結構聯(lián)結弱化,而且所產(chǎn)生的微裂紋,有利于地下水的浸入,從而加劇泥巖的軟化過程。(5)研究區(qū)泥巖軟化主要存在四種物理化學作用:一是以固體可溶鹽溶解析出為特征的化學溶蝕作用;二是伴隨泥巖溶蝕、孔隙增多增大過程的楔劈作用;三是泥巖中白云母、長石的水解作用;四是水的潤滑作用。其中,化學溶蝕作用是主要的,且隨飽水時間的增加而減弱,楔劈作用主要發(fā)生在飽水的中后期(即化學溶蝕進行到一定程度);水解作用總體比較微弱,潤滑作用主要存在于有貫通裂隙的情況(如泥巖結構面的情況)。(6)將泥巖(塊)及結構面的軟化過程大體上都分為三個過程。泥巖(塊):軟化開始階段(飽水0~10天)→軟化持續(xù)階段(飽水10~30天)→軟化穩(wěn)定階段(飽水30~60天);泥巖結構面:軟化開始階段(飽水0~5天)→軟化持續(xù)階段(飽水5~30天)→軟化穩(wěn)定階段(飽水30~60天)。
[Abstract]:The research area is located on the east side of the 12 # landslide of Panzhihua Airport. The bedrock of the site is mainly of the mudstone section of the Triassic Baoding Formation, mainly of the carbonaceous mudstone, with sandstone and silty mudstone. The underlying bedrock of the old landslide of the 10 # landslide and the lower Yijiaping landslide is mainly distributed with mudstone. The filling material is taken from the mudstone section of the Baoding Formation and contains a large amount of mudstone and fragment debris. It is clear that the failure of the filling body and the revival of the old landslide at the Panzhihua Airport are related to the softening of the mudstone. Therefore, a series of experiments have been carried out on the characteristics of the water softening of mudstone in the area, and the following understandings are drawn: (1) The initial component and structure of the mudstone are mudstone (block), and the surface of the mudstone is on the basis of water softening. The mudstone of the study area is mainly composed of clay minerals, organic minerals, simple salts and carbonaceous materials. In which the content of clay mineral accounts for 50-95%, the mineral content is 4-35%, and most of the simple salts are soluble salts. The carbonaceous content is from 1% to 10%, and the clay mineral is intermixed, and the connection between the clay mineral particles is reduced. From the microstructure, the clay mineral is a cryptocrystalline-microcrystalline aggregate, a parallel stack structure, and a solid salt is cemented between the clay mineral and the mineral particle. The above initial component structure determines that the natural strength of the mudstone in the study area is not high (the uniaxial compressive strength is less than 10MPa), the water stability is poor, and the softening property is strong. (2) The pure water soaking test shows that: (1) The water content and porosity of the mudstone (block) in the study area are continuously increasing in the water-saturated process, and the uniaxial compressive strength and the anti-shear strength show a continuous attenuation trend; after 30 days of saturation, the water content and the porosity of the mudstone are increased by 122.77%, respectively. 142.72%; single-axis compressive strength decreased by 81%, c, f value decreased by 67.86% and 53.12%, respectively; (2) the change tendency of the physical and mechanical properties of the mudstone structural plane was generally the same as that of the mudstone (block), but it was more severe than water and the softening process was faster. The anti-shear strength index is stable after 10 days of water saturation. After 30 days of water saturation, the water content and porosity increased by 166.67%, 195.97%, c, and f respectively by 63.27% and 41.67%, respectively. (3) The infiltration of mudstone has distinct characteristics of the opposite sex. In the non-stress state, the rate of water content, porosity and infiltration depth of the parallel bedding surface in the infiltration direction is higher than that of the vertical bedding plane. At different shear stress levels, the depth of infiltration along the direction of shear (potential destruction), the water content and porosity of the upper and lower test blocks increase with the increase of the shear stress level, the infiltration depth, the water content and the porosity in the parallel bedding of the shear plane are greater than that of the vertical plane shear. And the difference between the two stress levels is relatively large, and the difference between the two stress levels is small. (4) The effect of groundwater and stress is the main external factor leading to the softening of mudstone. Using the groundwater in the study area as the soak solution, the dissolution and precipitation of the chemical components of the mudstone are restrained to a certain extent, and the softening degree of the mechanical properties of the mudstone is less than that of the pure water soaking solution. In addition, under a certain stress, not only can the structural connection between the mudstone mineral particles be weakened directly, but also the micro-cracks are generated, which is beneficial to the immersion of the underground water, thereby increasing the softening process of the mudstone. (5) There are four physical and chemical functions of the softening of the mudstone in the study area: the first is the chemical dissolution which is characterized by the dissolution of the solid soluble salt; the second is the wedge action of the process of increasing the dissolution of the mudstone and the increase of the porosity; the third is the hydrolysis of the muscovite and the feldspar in the mudstone; And fourth, the lubricating effect of water. in which, the chemical corrosion action is main, and decreases with the increase of the water-saturated time, the wedge action mainly occurs in the middle and late period of water-saturated water (that is, the chemical dissolution is carried out to a certain degree), the hydrolysis effect is relatively weak, The lubrication effect mainly exists in the case of the through-crack (such as the case of the mudstone structure surface). (6) The softening process of the mudstone (block) and the structural surface is generally divided into three processes. Mudstone (block): softening start phase (water-saturated for 0-10 days), softening and steady phase (water-saturated for 10-30 days), softening and stabilizing phase (water-saturated for 30-60 days); mudstone structure surface: softening-start phase (water-saturated for 0-5 days) and softening-lasting stage (water-saturated for 5-30 days) and softening and stabilizing stage (water-saturated for 30-60 days).
【學位授予單位】：成都理工大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU45;V351.1

【參考文獻】

相關期刊論文 前10條

1 張國強;馮文凱;謝春慶;楊曦;吳屹;;風化裂隙水對高填方穩(wěn)定性的影響評價[J];工程勘察;2015年04期

2 姚遠;;利用CT掃描研究干濕循環(huán)泥巖軟化過程[J];工程勘察;2014年06期

3 任松;文永江;姜德義;陳結;屈丹安;楊春和;;泥巖夾層軟化試驗研究[J];巖土力學;2013年11期

4 張先偉;孔令偉;王靜;;針對黏性土膠質聯(lián)結特征的SEM-EDS試驗研究[J];巖土力學;2013年S2期

5 張先偉;孔令偉;;氧化鐵膠體與黏土礦物的交互作用及其對黏土土性影響[J];巖土工程學報;2014年01期

6 柴肇云;郭衛(wèi)衛(wèi);陳維毅;康天合;;泥巖孔裂隙分布特征及其對吸水性的影響[J];煤炭學報;2012年S1期

7 車平;宋翔東;虞翔;任凱杰;;巢湖地區(qū)墳頭組泥巖遇水軟化特性與機理試驗[J];同濟大學學報(自然科學版);2012年03期

8 冒海軍;郭印同;王光進;楊春和;;黏土礦物組構對水化作用影響評價[J];巖土力學;2010年09期

9 周翠英;朱鳳賢;張磊;;軟巖飽水試驗與軟化臨界現(xiàn)象研究[J];巖土力學;2010年06期

10 何蕾;文寶萍;李慧;;水在蘭州地區(qū)紅層風化泥巖抗剪強度中的綜合效應[J];水文地質工程地質;2010年03期

相關博士學位論文 前1條

1 劉曉明;紅層軟巖崩解性及其路基動力變形特性研究[D];湖南大學;2006年

，

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