【摘要】：炭質(zhì)泥巖廣泛分布于我國西南部地區(qū),由于其具有水理性強(qiáng)、易風(fēng)化、強(qiáng)度低、變形大等特點(diǎn),在以往的公路建設(shè)中常作為不良填料予以廢棄,但是隨著我國高速公路建設(shè)的快速發(fā)展,很多地區(qū)適宜的填料極為匱乏,從經(jīng)濟(jì)和環(huán)保兩方面考慮,利用炭質(zhì)泥巖進(jìn)行路堤填筑勢在必行,如何保證施工過程中以及工程建成后的工程安全便成為公路建設(shè)者們最關(guān)心的問題之一。因此,有必要開展炭質(zhì)泥巖-土分層填筑路堤穩(wěn)定性研究,以期為炭質(zhì)泥巖-土分層填筑公路路堤的設(shè)計(jì)與施工提供可靠依據(jù)。本文以廣西六寨至河池高速公路為工程依托,針對炭質(zhì)泥巖-土分層填筑路堤穩(wěn)定性的影響因素,從多方面對路堤穩(wěn)定性進(jìn)行了較為深入的研究。主要研究內(nèi)容如下：(1)崩解炭質(zhì)泥巖抗剪強(qiáng)度參數(shù)研究。通過炭質(zhì)泥巖直接剪切試驗(yàn)可知：含水率是影響炭質(zhì)泥巖粘聚力和內(nèi)摩擦角的主要影響因素,內(nèi)摩擦角是影響炭質(zhì)泥巖路堤填筑材料的抗剪強(qiáng)度的主控因素。(2)基于極限平衡條分法的分層填筑路堤穩(wěn)定性研究�；谌鸬鋱A弧法和簡化Bishop法極限平衡條分法進(jìn)行相關(guān)推導(dǎo),得到可以適用于不同材料的分層填筑路堤的瑞典圓弧法和簡化Bishop法計(jì)算方法。通過對比分析可知：分層填筑路堤穩(wěn)定計(jì)算方法較采用極限平衡法計(jì)算軟件數(shù)值模擬所得的安全系數(shù)更小,其在工程應(yīng)用更安全,經(jīng)濟(jì)效益更佳,對實(shí)際工程的設(shè)計(jì)和施工具有較強(qiáng)的指導(dǎo)性意義。(3)填筑材料強(qiáng)度參數(shù)變化對路堤穩(wěn)定性影響。通過縮小一定比例的室內(nèi)路堤模型試驗(yàn)對炭質(zhì)泥巖-土分層填筑路堤在降雨條件下的材料強(qiáng)度變化進(jìn)行研究。由室內(nèi)路堤模型試驗(yàn)和數(shù)值模擬可知：降雨開始時(shí),路堤穩(wěn)定性的安全系數(shù)迅速減�。唤涤攴�(wěn)定時(shí),路堤穩(wěn)定性的安全系數(shù)降幅不大；隨著降雨的持續(xù),路堤穩(wěn)定性的安全系數(shù)又迅速減小,且減小的幅度大于降雨開始階段。同時(shí),整個(gè)試驗(yàn)過程中時(shí),粉質(zhì)粘土和炭質(zhì)泥巖的重度、粘聚力以及內(nèi)摩擦角都呈現(xiàn)下降趨勢。
[Abstract]:Carbonaceous mudstone is widely distributed in the southwest of China. Because of its characteristics of strong water rationality, easy weathering, low strength and large deformation, it is often abandoned as a bad filler in highway construction in the past. However, with the rapid development of highway construction in China, the suitable fillers in many areas are extremely scarce. Considering both economic and environmental protection, it is imperative to use carbonaceous mudstone for embankment filling. How to ensure the safety in the construction process and after the completion of the project has become one of the most concerned issues for highway builders. Therefore, it is necessary to study the stability of carbonaceous mudstone-soil layered embankment in order to provide reliable basis for the design and construction of carbonaceous mudstone-soil stratified embankment. Based on the Liuchai-Hechi Expressway in Guangxi, the stability of embankment is studied from many aspects, aiming at the influencing factors of the stability of the embankment constructed by stratification of carbonaceous mudstone and soil. The main contents are as follows: (1) the shear strength parameters of carbonaceous mudstone disintegrating. Through the direct shear test of carbonaceous mudstone, it can be seen that water content is the main factor affecting cohesion and internal friction angle of carbonaceous mudstone. The angle of internal friction is the main factor that affects the shear strength of carbonaceous mudstone embankment. (2) the stability of layered embankment is studied based on the limit equilibrium strip method. Based on the Swedish arc method and simplified Bishop method, the calculation methods of Swedish arc method and simplified Bishop method are obtained, which can be used for layered embankment construction of different materials. Through comparison and analysis, it can be seen that the stability calculation method of layered embankment is smaller than that of numerical simulation software by using limit equilibrium method, and its application in engineering is safer and its economic benefit is better. It has a strong guiding significance for the design and construction of practical engineering. (3) the change of the strength parameters of the filling material affects the stability of the embankment. The change of material strength of carbonaceous mudstone-soil layered embankment under rainfall was studied by reducing a certain proportion of indoor embankment model test. From the indoor embankment model test and numerical simulation, it can be seen that the safety factor of embankment stability decreases rapidly at the beginning of rainfall, and the safety factor of embankment stability decreases slightly when rainfall is stable. With the continuous rainfall, the safety factor of embankment stability decreases rapidly, and the decrease is larger than that at the beginning of rainfall. At the same time, the density, cohesion and angle of internal friction of silty clay and carbonaceous mudstone decreased during the whole experiment.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U416.12

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 李廣居;瑞典法分析邊坡穩(wěn)定時(shí)的最危險(xiǎn)圓弧問題[J];水利水電技術(shù);1989年04期

，

本文編號：2307165