土石混合料的力学特性

Mechanical Properties of Broken Rock-Soil Mixture

利用特制的大型侧限固结仪对我国西部山区机场建设常用的不同土石混合比的填料进行试验,研究了土石混合料的压缩、蠕变和湿化变形等特性.结果表明:土石混合料中石料含量达70%～80%时,填料具有较大的密度,压缩性较小,初始蠕变速率也较小;同一混合料在特定压力下的蠕变量与时间对数近似呈线性关系,并且蠕变速率随应力水平的提高不断增大;高应力水平下,土石混合料遇水将产生很大的湿化变形,并且混合料中细粒土含量对填料的最终湿化变形量影响很大,在对工后沉降要求严格的工程中应对由填料的湿化变形引起的长期工后沉降给予高度重视.

With the help of a specially-designed large-scale oedometer,some experiments were carried out to investigate the compression,creep and wetting deformation of broken rock-soil mixture,which,with different broken rock contents,has been widely used in the airport construction in West China.The results show that the mixture is of high packing density,low compression and small initial creep rate when the broken rock content reaches 70%～80%,and that,for the same mixture at a certain pressure,the creep deformation is approximately linear to logarithmic time and the creep rate continuously increases with the stress level.Moreover,it is found that,when the mixture is submerged at a high stress level,significant wetting deformation may occur,and the final wetting defor-mation is greatly affected by the content of fine-particle soil in the mixture.Thus,it comes to the conclusion that,in the engineering with strict requirements for post-construction settlement,the long-term post-construction settlement due to wetting deformation should be paid more attention to.