The cement sand and gravel(CSG)dam is a new style of dam that owes the advantages both of the concrete faced rock-fill dam(CRFD)and roller compacted concrete(RCC)gravity dam,because of which it has attracted much attention of experts home and abroad.At present,some researches on physic-mechanical property of CSG material and work behavior of CSG dam have been done.This papcr introduces the development and characteristics of CSG dam systematically,and summarizes the progress of the study on basic tests,constitutive relation of CSG material and numerical analysis of CSG dam,in addition,indicates research and application aspect of the dam.
The multi-objective optimization method was used for shape optimization of cement sand and gravel (CSG) dams in this study. The economic efficiency, the sensitivities of maximum horizontal displacement and maximum settlement of the dam to water level changes, the overall stability, and the overall strength security were taken into account during the optimization process. Three weight coefficient selection schemes were adopted to conduct shape optimization of a dam, and the case studies lead to the conclusion that both the upstream and downstream dam slope ratios for the optimal cross-section equal 1:0.7, which is consistent with the empirically observed range of 1:0.6 to 1:0.8 for the upstream and downstream dam slope ratios of CSG dams. Therefore, the present study is of certain reference value for designing CSG dams.
基于动三轴试验,研究了不同围压、不同胶凝含量下胶凝堆石料的动本构关系及动模量衰减规律。结果表明,胶凝堆石料动本构关系仍可用Kondner R L双曲线模型进行描述,围压、胶凝含量对动本构关系均有影响,但围压对其影响较大;胶凝堆石料动模量随动应变的增大而非线性减小,且具有明显的应变软化特征,同等条件下动模量随围压和胶凝含量的增大而增大。根据动模量衰减曲线,提出了动模量衰减模型,通过线性回归分析,得到了胶凝堆石料动模量衰减模型参数表达式,为胶凝堆石坝的动力分析提供了参考。
