内外边界施加温度荷载的中空圆柱试样热固结试验

研制了一个轴对称的适用于中空圆柱试样的热固结试验装置。该装置可独立施加和控制试样内、外的温度荷载,并保持试样径向温度梯度的存在,且可施加径向固结压力,适用于特定的温度和应力耦合作用路径的试验。进行了一种饱和黏性土的热固结试验,即在试样内边界和外边界交替逐级施加范围为25℃~75℃的温度荷载,包括径向压力为50,100,150,200 k Pa的4种情形,分析了孔隙水压力及热固结体应变随时间的演化过程。研究表明,加热等级和加热次序不同,在同样的最终温度荷载下孔隙水压力稳定后的最大值有较大差异而体应变也不同,实际上反映了温度荷载作用路径对试样热固结效应的显著影响。

Consolidation tests on saturated soils subjected to thermal loading on inner and outer surfaces of hollow cylindrical specimens

An axial thermal consolidation test apparatus suitable for saturated soils is developed. Using this apparatus, thermal loadings can be applied on both the inner and outer surfaces of a hollow cylindrical specimen separately. Thus, the specimen will be subjected to the effect of a gradient temperature along the diameter and also a lateral mechanical loading. This apparatus can be used for some special heating paths and mechanical loading paths. The consolidation of a saturated soil is accomplished, and the thermal loading on the inner and outer boundaries of the specimen is applied by steps alternately. The temperature range is 25℃~75℃, and the lateral pressures are 50, 100, 150, 200 kPa. The results show that the pore pressures and consolidation volumetric strains of the specimens induced by heating steps and various heating orders are very different even under the same state of temperature loading, which actually indicates the obvious influences of heating paths.