【作者】 杨成忠；

【导师】 杨平；

【作者基本信息】 南京林业大学 ， 森林工程， 2008， 博士

【摘要】 我国西部山区地形地质条件复杂,路线中存在不少深挖路堑和隧道工程。为了充分利用路堑和隧道开挖产生的石质弃渣,并减少弃渣对沿线生态环境的破坏和诱发地质灾害,高填石路堤已成为山区高等级公路较普遍的路基型式。但缺乏与之相关的设计方法和理论研究,尤其是对复杂环境中的高填石路堤缺乏系统研究。因此,本文结合沪蓉西高速公路填高70余m的干沟高填石路堤,通过室内试验、现场试验和监测、理论研究、数值计算等方法,对填石材料基本性能和填石路堤稳定性分析、沉降预测、质量控制技术与标准进行了系统研究,主要获得如下成果:(1)针对隧道弃渣用作路堤填料,引入分维数评价其粒度组成。当分维数介于1.887~2.631时,表明弃渣级配良好,符合路基填料对级配的要求;(2)提出用超粒径颗粒质量百分数修正用合适尺寸颗粒击实得到的密度,以修正后的密度作为含超粒径填石材料密度,从而为计算填石路堤压实度提供了新方法;(3)建立了2自由度填石路堤——振动压路机系统和完成现场试验,进一步验证了采用低频高幅振动压路机有利于填石路堤的压实;(4)基于极限平衡理论,系统研究了在复杂环境条件下,高填石路堤稳定性受水位变化、地表坡度变化、路堤高度变化、填筑过程的影响规律。其安全系数随水位上升、路堤高度增高、填筑高度增大和地表坡度的增加而降低。针对干沟高填石路堤,当水位高度高于地表20m、路堤高度超过34m、路堤填筑高度超过32m、地表坡度大于1:5时,路堤的安全系数显著降低;(5)高填石路堤的稳定性随填筑过程而变化。不仅要考虑路堤最小安全系数所在的具体位置,而且还应考虑安全系数变化最大位置。安全系数最小和安全系数变化最大位置都是施工动态控制的关键因素;(6)针对高填石路堤分级填筑时自重作用下的沉降引入龚帕斯生长曲线进行全过程沉降分析与预测。用龚帕斯成长曲线预测其工后沉降比用双曲线预测其工后沉降精度要高;(7)通过数值计算,研究了陡坡上高填石路堤受力和变形规律。竖向压力和横向压力均随路堤深度的增加而加大,其最大值均发生在填筑高度最大的地表附近区域。陡坡上高填石路堤在竖直方向和水平方向均产生不均匀沉降。不均匀沉降随路堤高度的增加而增加,横向变形随路堤深度的增加逐渐减小;路堤压实越密实,路堤模量越大,横向变形差异和不均匀沉降越小;(8)采用施工工艺参数与沉降差结合,是填石路堤压实质量检测的有效方法。当以沉降差作为质量控制标准时,采用激振力大于40吨的振动压路机碾压最后两遍后沉降差不大于2mm的标准是合适的。更多还原

【Abstract】 The topographic and geological condition in the western mountainous area in our country is so complicated that there are many cutting and tunnel engineering while highway is constructed. In order to make full use of the waste rocky slag and reduce the damage to environment and cause geologic hazard, the high rock fill embankment has become one of the basic types of embankment structure. But corresponding design method and theory on these are lack, especially in complicated environment. Therefore, in this paper, combing with Gangou high rock fill embankment which high exceeds 70m in Hurongxi express highway, by means of laboratorial experiment, field experiment and monitoring, theoretical research and numerical calculation, the basic performance, the stability and settlement prediction theory, the controlling technology and standard for high rock fill embankment are researched and discussed. The main contents completed are as follows.(1)Aiming at tunnel waste slag as embankment filling material, fractal dimension is introduced to evaluate its granulometric composition. While the fractal dimension distributes from 1.887 to 2.631, the graduation is well and meet the requirement;(2)The method to calculate the field density of rock filling material by mass percent of over size measuring in field revising the density in the laboratorial experiment with suitable size is put forward, which provide a new method for compactness calculating;(3)By establishing rock fill embankment and vibratory roller system with 2 degree of freedom and completing field experiment, the vibratory roller operating with low frequency high amplitude is favorable for compacting rock fill embankment.(4)Based on ultimate equilibrium theory, applying 4 stability analyzing method, the changing discipline of stability of high rock fill embankment in complex environment influenced by water level, the earth’s surface gradient, embankment high and filling courses are systematically researched. safety factor become smaller with water level rising, embankment high heightening, filling high going up and grade becoming steep.the safety factor decline markedly while water level exceed 20m, embankment high exceed 34m, filling high exceed 32m and grade exceed 1:5.(5)The stability of high rock fill embankment changes with filling course. Not only the position with minimum safety factor but also the position with maximum safety factor change should be considered. The minimum safety factor and maximum safety factor change all are key factors in dynamic state monitoring in construction.(6)Aiming at the settlement of Gangou high rock fill embankment caused by embankment weight with steps filling, Compertz Growth Curve is applied to analyze and predict the settlement in whole course. The precision of predicting settlement by Compertz Growth Curve exceeds that by hyperbola;(7)By numerical calculation, the stress and deformation discipline of high rockfill abrupt slope embankment are researched. Both Vertical stress and transverse stress increase with embankment depth. The maximum occur near the earth’s surface area where the filling high is the maximum. Abrupt slope high rock fill embankment take places asymmetric settlement at both vertical direction and transverse direction. The asymmetric settlement value become greater with embankment’s high increasing, while the transverse deformation become smaller with embankment’s high increasing; the more closed, the modulus greater, the transverse deformation discrepancy and Asymmetric settlement become smaller.(8)Combing construction technics with settlement discrepancy to detect compacting quality of rock fill embankment is an effective means. While adopting settlement discrepancy as the standard to quality controlling, 2 mm settlement discrepancy after the vibratory roller with 40 ton exciting force compacted is appropriate.更多还原