【摘要】：在四川攀西地區(qū)特有的“昔格達”地層多屬于粉沙質(zhì)泥巖,強風化巖石,遇水即會崩解溶化成泥漿狀態(tài),灰褐色的泥質(zhì)粉砂巖中夾有鈣質(zhì)粉砂巖,強度風化,極為松軟,圍巖不能自穩(wěn),抗壓強度極低,為極不穩(wěn)定的泥砂巖。昔格達地層交通建設的實踐表明,在建設過程中會誘發(fā)規(guī)模較大的滑坡、崩塌、滲水、軟化、流變、隧道圍巖變形坍塌破壞等各類災害。目前穿越昔格達地區(qū)面臨的工程地質(zhì)問題日益突出,很多方面技術(shù)不成熟,直接影響鐵路和公路建設的正常進行,不能滿足當前交通建設快速發(fā)展的需要。本文以新建成昆鐵路米易至攀枝花段擴能工程為工程依托,采用現(xiàn)場調(diào)研及查閱資料、理論分析、數(shù)值模擬、室內(nèi)土工實驗等手段結(jié)合的方法進行研究,針對昔格達地層遇水崩解軟化的的特殊工程性質(zhì),通過室內(nèi)土工試驗研究了含水率對昔格達地層圍巖物理力學性質(zhì)的影響規(guī)律,并結(jié)合國內(nèi)學者研究成果對5種昔格達地層土樣的圍巖進行了進一步的圍巖分級。本文引入強度折減法作為昔格達地層隧道圍巖穩(wěn)定性的評價方法,以隧道特征點的位移是否突變作為隧道的失穩(wěn)判據(jù),結(jié)合數(shù)值模擬,研究了含水率對昔格達地層隧道圍巖穩(wěn)定性影響,給出了評價昔格達地層隧道圍巖穩(wěn)定性定量的評價方法。最后,對目前控制圍巖穩(wěn)定性的常用施工工法在昔格達地層中的適用性進行了分析,根據(jù)設計、施工單位反饋的信息,重點研究了結(jié)合鎖腳錨桿的三臺階短臺階法和三臺階超短臺階法控制昔格達地層圍巖穩(wěn)定性的效果。
文內(nèi)圖片：
圖片說明：圖２－１昔格達地層淺灰色頁巖遇水前后形態(tài)對比圖逡逑
[Abstract]:Most of the "Xigda" strata in Panxi area of Sichuan Province belong to silty mudstone, and the strongly weathered rock dissolves and dissolves into mud state when water is encountered. Calcareous siltstone is sandwiched in the grayish-brown argillaceous siltstone, which is very soft, the surrounding rock can not stabilize itself, and the compressive strength is very low. The practice of traffic construction in Xigeda strata shows that large scale landslides, collapses, seepage, softened, Rheological, deformation and collapse of tunnel surrounding rock will be induced in the process of construction. At present, the engineering geological problems faced by Xigeda area are becoming more and more prominent, and the technology is not mature in many aspects, which directly affects the normal progress of railway and highway construction and can not meet the needs of the rapid development of current traffic construction. Based on the newly built capacity expansion project of Miyi to Panzhihua section of Kunming Railway, this paper studies the special engineering properties of Xigeda formation when water collapses and softens by means of field investigation and consulting data, theoretical analysis, numerical simulation, indoor geotechnical experiment and so on, and studies the influence of moisture content on the physical and mechanical properties of Xigeda formation surrounding rock through indoor geotechnical test. Combined with the research results of domestic scholars, the surrounding rock of five kinds of Xigeda formation soil samples was further classified. In this paper, the strength reduction method is introduced as the evaluation method of surrounding rock stability of Xigeda strata tunnel, and whether the displacement of tunnel characteristic points is abrupt or not is taken as the instability criterion of tunnel. Combined with numerical simulation, the influence of water content on the stability of surrounding rock of Xigeda formation tunnel is studied, and the quantitative evaluation method of surrounding rock stability of Xigeda strata tunnel is given. Finally, the applicability of the common construction methods to control the stability of surrounding rock in Xigeda strata is analyzed. According to the information of design and construction unit feedback, the effect of three-step short step method and three-step ultra-short step method combined with anchor rod to control the stability of surrounding rock of Xigeda formation is studied.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U455.49

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本文編號：2509970