土石混合料的渗水湿化对高填方体变形的影响研究
发布时间：2019-05-19 08:03
【摘要】：随着国民生产水平快速增长,机场的建设及扩建也进入了井喷时代,山区的高填方工程越来越多。场区地形高低起伏,土石挖填方工程量大,且水文地质条件较复杂,水位随季节变化明显,在降雨或者地下水渗流过程中,填料的浸湿会引起湿化沉降。如何准确评价填方体在湿化条件下的沉降及差异沉降规律,使高填方体在施工期和工后的沉降及差异沉降满足工程要求是非常重要的问题。本文通过现场试验和对工程现场的长期分层沉降监测,结合FLAC3D数值模拟,研究了湿化条件下高填方体的沉降及差异沉降相比天然工况下的增大程度。主要的研究内容和研究成果如下:①分析了土石混合填料的湿化变形机理及影响因素。通过现场单环注水试验,得到研究区填方体的渗透系数;通过现场探槽开挖试验,得到填土体的含水率沿剖面纵向的变化规律。再利用经验公式计算得出该研究区降雨入渗的影响深度。②通过对填方体的分层沉降监测,施工加载期的最大沉降量为43.09cm,沉降速率为0.71~2.56mm/d,加载结束后的沉降速率为0.13~0.32mm/d。沉降速率及沉降量与填方体高度、施工填筑速率成正相关,含水率随土体深度变化的表达式为y=-0.0484x2-0.1781x+10.468,当含水率增大时,沉降速率也有一定的增大。③利用Auto CAD—ANSYS—FLAC3D三者结合建立复杂地形下的三维数值模型。X和Y方向位移较大部位均发生在边坡处,边坡坡度越大,位移值越大。Z向的沉降主要取决于填方体的高度,在最高填方高度29.8m处的最大沉降值为52.93cm。最大差异沉降率和平均差异沉降率分别为11.42‰和3.41‰。湿化条件下选取了三种工况:降雨入渗湿化影响深度分别为5m、10m、20m,对应的地下水位上升1m、3m、5m,得到最大沉降变形相比天然工况下增大比例分别为3.5%、12%和20%左右,且湿化深度的增加对填方体沉降的影响要比地下水位上升产生的影响大。将其与实际监测结果对比发现与工程的实际情况较为吻合。④基于多因素正交极差分析原理,对影响填方体沉降的参数敏感性进行了分析,得到敏感性顺序为:变形模量E0密度?粘聚力c内摩擦角?泊松比μ。基于已有的监测数据,对岩土体力学参数进行反演研究,并将反演得到的参数代入模型对其余监测点进行计算,结果表明反演得到的参数是比较合理的。
[Abstract]:With the rapid growth of national production level, the construction and expansion of airport has entered the era of blowout, and there are more and more high fill projects in mountainous areas. The topography of the field area is undulating, the quantity of earth-rock excavation and filling is large, and the hydrogeological conditions are complex, and the water level varies obviously with the season. in the process of rainfall or groundwater seepage, the wetting of the packing will cause humidification settlement. How to accurately evaluate the settlement and differential settlement of the fill under the condition of humidification, so that the settlement and differential settlement of the high fill during and after construction meet the engineering requirements is a very important problem. In this paper, the settlement and differential settlement of high fill under humidification condition are studied by field test and monitoring of long-term layered settlement in engineering site, combined with FLAC3D numerical simulation. The main research contents and results are as follows: 1. The humidification deformation mechanism and influencing factors of soil-rock mixed fillers are analyzed. Through the field single ring water injection test, the permeability coefficient of the fill body in the study area is obtained, and the variation law of the moisture content of the filled soil along the longitudinal direction of the section is obtained through the field grooving excavation test. The influence depth of rainfall infiltration in the study area is calculated by using the empirical formula. 2 through the layered settlement monitoring of the fill, the maximum settlement of the construction loading period is 43.09 cm, and the settlement rate is 0.71 鈮，
本文编号：2480544
[Abstract]:With the rapid growth of national production level, the construction and expansion of airport has entered the era of blowout, and there are more and more high fill projects in mountainous areas. The topography of the field area is undulating, the quantity of earth-rock excavation and filling is large, and the hydrogeological conditions are complex, and the water level varies obviously with the season. in the process of rainfall or groundwater seepage, the wetting of the packing will cause humidification settlement. How to accurately evaluate the settlement and differential settlement of the fill under the condition of humidification, so that the settlement and differential settlement of the high fill during and after construction meet the engineering requirements is a very important problem. In this paper, the settlement and differential settlement of high fill under humidification condition are studied by field test and monitoring of long-term layered settlement in engineering site, combined with FLAC3D numerical simulation. The main research contents and results are as follows: 1. The humidification deformation mechanism and influencing factors of soil-rock mixed fillers are analyzed. Through the field single ring water injection test, the permeability coefficient of the fill body in the study area is obtained, and the variation law of the moisture content of the filled soil along the longitudinal direction of the section is obtained through the field grooving excavation test. The influence depth of rainfall infiltration in the study area is calculated by using the empirical formula. 2 through the layered settlement monitoring of the fill, the maximum settlement of the construction loading period is 43.09 cm, and the settlement rate is 0.71 鈮，
本文编号：2480544
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