强自重湿陷性黄土湿陷范围浸水试验研究

Water immersion test study on collapsible range of strong self-weight collapsible loess

在兰州市榆中县和平镇38~42m厚自重湿陷性黄土场地上,做直径20m圆形试坑的现场浸水试验,试验持时69d,其中浸水观测62d、停水后观测7d,总用水量4346m3。重点考察了湿陷性黄土的湿陷范围、湿陷速率变化规律及裂缝发展规律。试验结果表明,湿陷性黄土的湿陷有一定范围,15m以下沉降量较小,渗透最大影响深度约为25m,且大厚度自重湿陷性黄土湿陷范围呈先局部后整体,先近后远,近密远疏,逐步扩展的变化规律。

On-site water immersion test of a 20m diameter test pit was carried out on a 38~42m thick self-weight collapsible loess site in Heping town,Yuzhong county,Lanzhou city.The test lasted for 69 days,including 62 days of immersion observation and 7 days of observation after water stoppage.The total water consumption is 4346m3.The collapsible range of collapsible loess,the variation law of collapsible rate and the law of crack development were mainly investigated.The experimental results show that the collapsible loess has a certain collapsible range,the subsidence is small below 15m,and the maximum penetration depth is about 25m.The collapsible range of large-thickness self-weight collapsible loess shows a changing law of local first and then the whole,near first and then far,near dense and far sparse,and gradually expanding.