共查询到19条相似文献,搜索用时 406 毫秒
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结合施工场地所处区域水文地质条件,利用MODFLOW数值模拟软件,模拟边坡的地下水渗流场的情况,再建立一定精度的数值模型,并输入实际的各种参数,通过和实际结果相比较,验证模拟的可行性之后,对不同边坡的工况进行模拟,获得对实际具有参考价值的各种数据。指出利用渗流场模拟结果,综合其他有关情况,能更好地有针对性对边坡开展治理设计工作。 相似文献
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本文建立非线性回归方法与地下水三维数值模型———MODFLOW相结合的优化模型 ,利用含水层抽水试验资料确定含水层水平渗透系数Kr 和储存率Ss,以及上覆弱透水层垂直渗透系数Ka 和给水度Sy。通过 2个示例分析模型计算过程 ,结果表明 ,该模型不仅能有效地确定这些水文地质参数 ,而且可以给出计算参数的误差范围和参数之间的相关程度 相似文献
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隧道开挖问题的水力耦合计算分析 总被引:15,自引:0,他引:15
隧道工程中的地下水问题是富水地层中普遍存在的重要问题,地下水流动对隧道围岩稳定性有重要影响。本文利用解析法给出了饱和孔隙介质地层中考虑地下水渗流力作用下的应力。位移表达式;提出了隧道水力耦合数值分析中的耦合计算模型的建立方法并进行数值模拟分析。数值计算结果表明在考虑渗流影响条件下,隧道周边位移最大增加17.0%,最大剪应力最大增加10.3%。在不考虑衬砌条件下,由于渗流引起的渗流力增加了围岩的应力、位移,从围岩-支护结构共同作用原理考虑,进行隧道支护结构设计时是应该考虑渗流效应的。 相似文献
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以某邻近地铁结构的深基坑工程为例,采用等效刚度法将围护桩等效为地下连续墙建立有限元模型对基坑地下水渗流过程进行了三维数值分析,分析了基坑地下水渗流对邻近地铁结构影响,提出了优化改进措施以减小地下水渗流影响,对于指导工程实践有一定意义。 相似文献
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隧洞地下水渗流场变化对衬砌受力影响的数值分析 总被引:1,自引:0,他引:1
为研究隧洞地下水渗流场变化对衬砌结构受力的影响,通过建立平面应变渗流耦合有限元模型,对隧洞开挖、设置排水管、进行固结灌浆等不同施工工况进行了数值模拟,动态地分析了不同施工措施时的地下水渗流场变化以及相应对衬结构受力的影响。 相似文献
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为解释常用的防渗体侧水压力计算模型与实测值之间的明显差异,文章提出:“节点间等效渗透系数”、“拓展零渗透节点”、“可变零渗透节点”等概念在分析地下水渗流场中的意义,以解决差分法对地下水渗流潜水面的数值模拟问题;并在模拟工程实例的基础上,对侧水压力实测的模拟结果和对常用防渗模型误差来源的分析;指出常用防渗模型侧水压力的分析误差主要是因该模型未能较准确反映实际流场而造成的;在工程应用中,防渗体侧水压力的确定应根据不同情况予以分别对待。 相似文献
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Seok-Won Lee Jong-Won Jung Seok-Woo Nam In-Mo Lee 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2007,22(1):28-38
When a tunnel is excavated underneath a groundwater table, groundwater flows into the tunnel and consequently, seepage forces act on the cross-section of the tunnel. Such seepage forces significantly affect the ground reaction curve, which is defined by the relationship between the internal pressure and displacement of the tunnel wall. From a practical point of view, a simplified analytical solution of the ground reaction curve accounting for the seepage forces with steady-state flow was developed in this study based on ground reaction curve theories from earlier studies. The simplified analytical solution derived in this study was validated by numerical analysis. The changes in the ground reaction curve according to various ground and groundwater table conditions were investigated. Finally, the simplified analytical solution of the ground reaction curve developed in this study can be used for approximate design of circular openings such as tunnels excavated underneath a groundwater table with seepage forces. 相似文献
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The study of seepage forces acting on the tunnel lining and tunnel face in shallow tunnels 总被引:7,自引:0,他引:7
In-Mo Lee Seok-Woo Nam 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2001,16(1):614
In this paper, the seepage force problems arising from the flow of groundwater into a tunnel were studied. Firstly, the effect of seepage forces acting on the tunnel lining was studied for the case of shallow drainage-type tunnels and these results were compared with the lining stresses developed for waterproof-type tunnels. This model was then reviewed through a comparison with an actual case study of the Seoul Subway Line No. 5. Secondly, the effect of seepage forces on the tunnel face stability was studied. In this study, two factors were considered simultaneously. The first factor considered was the effective stresses acting on the tunnel face, calculated from the upper bound solution of limit analysis and the other factor was the seepage forces, calculated from a numerical analysis under a steady-state of groundwater flow conditions. Consequently, reasonable design concepts applicable to the design of tunnel lining and to the evaluation of the support pressure required for maintaining the stability of the tunnel face were suggested for underwater tunnels. 相似文献
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针对目前应用广泛的解析计算方法,本文分析了砂土地基基坑工程井点降水的特点,基于有限元理论,考虑降水过程中渗流场与应力场的耦合作用,建立了考虑应力与渗流耦合的基坑降水的数值模型,并应用该模型分析地下水水位随时间的下降过程。工程实例分析表明,该模型比较符合实际情况,具有较强的适用性。 相似文献
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边坡虹吸排水数值模拟方法及应用 总被引:1,自引:0,他引:1
边坡虹吸排水是处于探索应用阶段的新技术。基于广义达西定律与渗流场分析的基本原理,将“以管代孔”法与解析单元法相结合,提出针对虹吸排水系统的数值模拟方法。按照流量和水头等价的原则,给排水孔赋予等效的渗透系数,并根据虹吸排水原理确定其内水头边界条件,以此模拟虹吸排水过程。建立边坡三维渗流有限元计算模型,以单个排水孔为例,计算虹吸排水作用前、后坡体内地下水位线与渗流场分布的变化,揭示了虹吸排水对边坡地下水渗流场的影响规律。在排水孔径和孔长恒定的条件下,模拟了排水孔位置变化对排水效果的影响,结果表明边坡虹吸孔位选择对排水效果有重要影响。 相似文献
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Young-Jin Shin Byoung-Min Kim Jong-Ho Shin In-Mo Lee 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2010,25(4):315-324
When a tunnel is excavated below groundwater table, the groundwater flows into the excavated wall of tunnel and seepage forces are acting on the tunnel wall. Such seepage forces significantly affect the ground reaction curve which is defined as the relationship between internal pressure and radial displacement of tunnel wall. In this paper, seepage forces arising from the ground water flow into a tunnel were estimated quantitatively. Magnitude of seepage forces was estimated based on hydraulic gradient distribution around tunnel. Using these results, the theoretical solutions of ground reaction curve with consideration of seepage forces under steady-state flow were derived. A no-support condition was taken into account. The theoretical solution derived in this study was validated by numerical analysis. The changes in the ground reaction curve according to various ground and groundwater conditions were investigated. Based on the results, the application limit of theoretical solution was suggested. 相似文献