不同厚度红砂岩粗粒土静力压实特性试验研究

Test and Research on Impact of Soil Layer Thickness on Compaction Properties of Coarse-grained Red Sandstone Soil

为研究红砂岩粗粒土压实特性,利用自制装置在电子万能试验机上进行静力压实试验,得到5种不同厚度红砂岩粗粒土静力压实试验的应力-应变关系,分析压实厚度和压实能量对红砂岩粗粒土压实特性的影响。结果表明:红砂岩粗粒土在压实过程中的应力与应变之间呈指数关系;压实过程可分为压密阶段、破碎阶段和稳定阶段;不同压实厚度的土层压实位移随压实能量增长趋势基本一致,所消耗压实能量随土层厚度增加而増大;土体干密度随单位体积静压功增加而增大,两者可采用对数关系描述;压实到相同干密度,所消耗的单位体积静压功随压实厚度增高而增大,故适当减小填土压实厚度将有利于降低能量消耗。

To research compaction properties of coarse-grained red sandstone soil, static load compaction tests are conducted by using electronic universal testing machine. Stress-strain relations of coarse-grained red sandstone soil are obtained and the effects of compaction thickness and compaction energy on compaction properties are analyzed. The results show that in the compaction test of coarse-grained red sandstone soil, relationship between the stress and strain is exponential. Three stages are included by the following order during compaction process： rapid compression deformation stage, slow compaction deformation stage and stable compaction stage. Different thickness of soil compacting displacement increases with the growth of the compaction energy, and the compaction energy becomes larger with the increase of soil layer thickness. In the process of compaction, dry density of soil increases with unit-volume static compaction work. The relationship between unit-volume static compaction work and dry density can be described as logarithm relation. Compact the soil to the same dry density, unit-volume static compaction work increases with the compaction thickness, so reducing the filling compaction thickness appropriately will be conducive to reduce energy consumption.