西韩城际铁路湿陷性黄土地层现场浸水试验研究

在分析西韩城际铁路沿线黄土分布特征的基础上,选取代表性场地开展现场试坑浸水试验。试验结果表明:场地实测最大自重湿陷量为46 mm,仅为室内压缩试验计算值的0.23倍;湿陷土层厚度15 m,除Q;黄土全部具有湿陷性外,Q;上部黄土亦具有湿陷性;地表水自然入渗深度超过50 m,浸润角约为40°,浸润范围约为浸水试坑直径的1.7倍。对现场实测值和室内计算值差异原因进行深入分析,得出在黄土结构未完全破坏之前,发生过湿陷的土体在特定条件下还有可能再次湿陷的结论。

A Study of In-situ Water Immersion Test on Collapsible Loess of Xi’an-Hancheng Intercity Railway

On the basis of analyzing the distribution characteristics of loess along the Xi’an-Hancheng Intercity Railway,a representative site was selected to carry out the in-situ water immersion test.The experimental results show that the measured maximum self-weight collapse value is 46 mm,which is only 0.23 times of the calculated value of indoor compression test.The collapsible soil layer thickness is 15 m.Except for all the loess in Q;,the loess in the upper part of Q;is also collapsible.The natural infiltration depth of surface water is more than 50 m,the infiltration angle is about 40°,and the infiltration range is about 1.7 times of the diameter of the immersion test pit.The reasons for the difference between the in-site measured and calculated values in the laboratory are analyzed deeply,and it is pointed out that before the loess structure is completely destroyed,the soil that has collapsed before may collapse again under certain conditions.