长河坝水电站砾石土击实特性及压实控制标准研究

The Study on the Characteristics of Compaction and the Standard of Compaction Control of Gravel Soil for Construction of the Changheba Hydropower Project

分析认为砾石土的击实最大干密度与土料母岩性质、风化程度、P5含量、击实功能等因素关系密切,增大试验仪器尺寸可提高砾石土的最大干密度,在试验条件允许时宜尽可能选用较大尺寸击实仪更符合实际。建议了一种砾石土最大干密度经验公式,计算结果与实测值十分吻合,该方法可大幅减少检测工作量、缩短检测时间以满足高强度大方量砾石土填筑质量检测控制需要。同时对全料压实度与细料压实度相关关系进行了分析研究,得出细料压实度并不是一个定值,随P5含量的增大而降低。研究表明设计标准是合理的。

The paper holds that the maximum dry density of compaction of gravel soil is closely related with such factors as soil material parent rock properties ,degree of weathering ,P5 content and compaction func-tion .Magnification of the dimensions of the test instrument can increase the maximum dry density of grav-el soil .When the test condition permits ,it is preferable to select a large compaction test instrument as much as possible ,which more corresponds to the reality .The paper brings forward an empirical formula of maximum dry density of gravel soil .Its calculation result tallies with the measured value .The use of the test instrument with large dimensions can greatly reduce testing work load and shorten the testing time to meet the requirement of quality inspection and control of the gravel soil embankment placement in high in-tensity and large quantity .Furthermore the paper makes analysis and study on the correlation between the compactness of the w hole material and the compactness of the fine -grained material ,and concludes that the compactness of the fine-grained material is not a constant value and reduces with increase of P 5 con-tent .The study shows that the design standard is reasonable .