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土-水特征曲线(SWCC)是反映非饱和土工程特性的重要表现形式。由于原状土的取土及试验过程较为繁琐,所以现有非饱和土分析大多用重塑土,而重塑土的土-水特征曲线与原状土的特征曲线的对比研究还不充分。通过对石家庄地区非饱和原状土与同条件下的重塑土土-水特征曲线的测定,分析抽气饱和过程对SWCC的影响,对比原状土与重塑土的进气值、排水速率、排水量大小、残余饱和度对应的基质吸力、固结时间的量化差异。研究结果表明:抽气饱和对SWCC影响不大;原状非饱和土的进气值要低于重塑土的进气值;试验中由于原状土中有历史形成的大孔隙,土-水特征曲线的斜率比重塑土大,排水速率在试验前期大于重塑土;但原状土的排水量没有因这些大孔隙而比重塑土大;原状土达到残余饱和状态时的基质吸力比重塑土小;原状土比重塑土达到残余状态早、达到残余饱和度所需时间短。在此基础上,得到了更适合于石家庄地区区域性非饱和土土-水特征曲线的三参数拟合方程。
Soil-water characteristic curve (SWCC) is an important manifestation of engineering characteristics of unsaturated soils. Because of undisturbed soil borrowing and testing process is more complicated, so most of the existing unsaturated soil analysis using remodeled soil, and remolded soil soil - water characteristic curve and undisturbed soil characteristics curve comparative study is not sufficient. Through the determination of soil-water characteristic curve of unsaturated undisturbed soil in Shijiazhuang area and the remodeled soil under the same conditions, the influence of the process of suction saturation on the SWCC was analyzed. The air intake value, drainage rate and displacement of undisturbed soil and remolded soil Size, residual saturation corresponding to the matrix suction, consolidation time quantitative differences. The results show that the suction saturation has little effect on the SWCC. The intakes of intact unsaturated soils are lower than those of the remolded soils. Due to the history of macropores and soil-water characteristic curves The slope of the original soil is larger than that of the remolded soil, and the drainage rate is greater than that of the remolded soil at the early stage of the experiment. However, the displacement of the undisturbed soil is not larger than that of the remolded soil due to these large pores. ; Undisturbed soil than the remineralized soil to reach the state of remnants, the time required to reach residual saturation is short. On this basis, a three-parameter fitting equation that is more suitable for the soil-water characteristic curve of regional unsaturated soil in Shijiazhuang is obtained.