坝体的变形及稳定性计算分析中,合理地选择模拟填筑层数并考察水位对坝体变形及稳定性的影响是十分必要的。首先以变形和稳定性系数作为评价指标,利用强度折减法计算坝坡的稳定性系数,基于FLAC3D建立坝体的分层填筑三维数值模型,对施工填筑期的数值模拟填筑层数的选取标准进行了研究。其次,在合理的模拟填筑层条件下,研究了不同蓄水位对坝体的变形和稳定性的影响。结果表明:坝体的变形以沉降为主,模拟计算的坝体沉降与填筑层数关系很大。相对坝体沉降来说,水平位移和稳定性系数对填筑层数的敏感性小,应以满足坝体沉降的精度标准选择模拟填筑层数,建议模拟填筑层数不少于10层,坝越高,选取的模拟填筑层数宜越多;坝体的水平位移对库水位位置较敏感,沉降和稳定性系数对库水位位置敏感性小。这些结果在坝体变形和稳定性研究中对确定合适的填筑层数和考虑库水位的影响具有指导意义。
To select the number of filling layer rationally and consider the influence of water level on deformation and stability is necessary in the numerical simulation of dam deformation and stability. Firstly, deformation and stability coefficient are selected as assessment indexes, and strength reduction method is introduced to calculate the stability coefficient of dam slope. Moreover, 3-D numerical model of layered filling is set up based on FLAC3D to study the criteria of selecting the number of filling layer. Furthermore, on the basis of appropriate number of filling layer, the effect of water level on the deformation and stability of dam body is discussed. Results show that settlement is the predominant deformation and simulated settlements are closely related with the number of filling layer. Compared with settlement, horizontal displacement and safety factor are less sensitive to the number of filling layer which should be chosen according to the requirement of settlement precision; it is advised that the number of filling layer is not less than 10 layers, and the higher the dam, the more the number of filling layer should be. The horizontal displacement is more sensitive than the settlement and stability coefficient to water level of reservoir. These results are of guiding significance to determining the appropriate number of filling layer simulation.
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