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对兰州地区Q3大厚度自重湿陷性黄土场地进行了不设注水孔,埋设水分计和热传导吸力探头的浸水试验。研究结果表明:大厚度黄土场地的不同深度土层均会出现多次湿陷,湿陷次数随着土层深度的增加将减少;体积含水率在不同深度土层中呈现不同的变化规律,10 m以上基本由6段组成,10～22.5 m由5段组成,而22.5 m以下则由3段组成;25 m以上范围内水分入渗较为容易,该深度以下土层,由于上部土体发生湿陷压密以及空隙中的气体压力增大导致了水分入渗缓慢;离试坑周边较远的裂缝的产生由于试坑较近裂缝剧烈活动引起;水分运移基本呈现椭圆状形态入渗(长轴位于水平向),后期整个椭圆状湿润区的离心率越来越小,椭圆更扁;浸润角随着外部水源不断供给逐渐扩大,本次试验其变化范围在0°～55°;场地中水分入渗率基本呈现出幂函数减趋势。
The water immersion test with no water hole, buried moisture meter and heat conduction suction probe was conducted on the large thickness self-weight collapsible loess site Q3 in Lanzhou. The results show that there are multiple collapses at different depths in large thickness loess sites, and the number of collapses will decrease with the depth of soil depth. The volumetric water content shows different variation rules in different depths of soil layers. 10 m above consists of 6 sections, 10 ~ 22.5 m is composed of 5 sections, while 22.5 m is composed of 3 sections. The infiltration of water above 25 m is easy. Under this depth, due to wet The trapped pressure and the increase of gas pressure in the voids resulted in the slow infiltration of water. The fissures farther away from the periphery of the pit were caused by the violent activities of cracks near the test pit. The water migration showed an oval shape infiltration Axis is horizontal), the eccentricity of the entire oval-shaped moist zone is getting smaller and smaller, the oval is more flat. The infiltration angle gradually increases with the continuous supply of external water source. The variation ranges from 0 ° to 55 ° in this experiment. Moisture infiltration rate showed a power function trend.