贵州地区板溪群板岩填料路用工程特性及路基结构设计研究

Study on Road Engineering Properties and the Design of Subgrade Structure of Banxi Group Slates Filling in Guizhou

针对贵州地区板溪群板岩填料的路用工程特性开展了一系列的室内试验研究,重点研究了干湿循环效应下板岩填料的CBR和回弹模量变化特征。试验表明：板岩填料长期强度受干湿效应与风化作用衰减显著,其CBR和回弹模量随试样浸水时间增加逐渐降低,浸水6~7 d后趋于稳定;CBR与回弹模量随着干湿循环次数增加不断衰减,5次循环后趋于稳定,且干湿循环引起的强度衰减幅度要大于单次浸水。因此,建议采用5次干湿循环后CBR值作为板岩填料的长期强度指标。试验表明该类填料的长期稳定CBR值满足路堤填料强度要求。最后,给出了贵州地区高速公路板岩路堤典型结构,可为类似工程提供参考。

A series of laboratory experiments about the Banxi group slate filling road engineering properties was carried out,which focuses on the change of CBR and resilient modulus characteristics un- der the dry-wet cyclic. The tests show that the slate filling long-term strength was effected significantly by dry-wet cyclic or weathering effect, the CBR and resilient modulus was gradually reduced as the immer- sion time increased, and after 6 to 7 days, it tends to be stable. CBR and resilient modulus was constantly reduced as the number of dry-wet cycles, after 5 cycles, it tend to be stable. Therefore, it is suggested that the value of CBR and resilient modulus after 5 dry-wet cycles is used as the long-term strength in- dex. The test shows that the long-term stability of Banxi group slates filling meets the strength require- ments of embankment. At last, this paper gives the typical structures of slate embankment of Expressway in Guizhou area, it can be provided a reference for the similar engineering.