白浆土某些物理性质的研究Ⅱ.土壤抗剪强度及脆性

摘要

To explore the physical characteristics of planosol,the highland planosol in east of Heilongjiang province was taken as texted soil,anti-shear strength and brittleness of planosol were determined and analyzed.The results showed that the cohesion of albic soil layer was the biggest in planosol,followed by the deposition layer soil and topsoil.Soil adhesion of deposition layer soil was the biggest in planosol,followed by the albic soil layer and topsoil.The external friction angle of soil was increasing fro topsoil to deposition layer.The cohesion and friction angle of soil were reduced when soil moisture increased,soil adhesion opposite.Topsoil was most easily broken in planosol,deposition layer soil hard to be broken.When water content of topsoil and the deposition layer soil was lower than soil plastic limit stage,the energy consumption of crushing soil increased with soil water content increasing,and it formed the peak stage when it was up to the soil plastic limit.The energy consumption of crushing soil decreased with soil water content increasing,it formed different sized clod when the soil was destroyed,large clod ratio increased with soil water content,topsoil was easily broken into smaller blocks and soil crumbs,deposition layer soil was not easily broken.%为探究白浆土机械物理性质,以黑龙江东部岗地白浆土为供试土壤,采用现场试验法和钢材脆性仪测定了白浆土原状土壤的抗剪强度和脆性。结果表明：白浆土内聚力白浆层最大,依次为淀积层、耕层;土壤粘着力淀积层最大,依次为白浆层、耕层;土壤外摩擦角由耕层向淀积层呈逐渐增加趋势。土壤水分升高,内聚力和内外摩擦角均有降低趋势;而土壤粘着力则相反。白浆土耕层土最易被破碎,白浆层居中,淀积层难以破碎。耕层和淀积层土壤在含水量低于塑性界限值阶段,破碎土壤所消耗的能量随土壤含水量增加而增加,并在土壤塑限值附近形成峰值,之后随土壤含水量增加而降低。破碎白浆层土壤所消耗的能量随土壤含水量增加而降低。破坏土壤时形成大小不一的土块,大土块比率随土壤水分增加而增加。耕层土壤易破碎成较小的土块和土屑;白浆层土壤居中,淀积层不易破碎。