郑西客运专线黄土地基湿陷性现场浸水试验研究

在分析郑西客运专线黄土分布特征的基础上,选取8个典型工点进行黄土地基湿陷性现场浸水试验.试验结果表明:郑州至渑池段2个试验场地最大自重湿陷量为0.47～2.65 cm,属于Ⅱ级非自重湿陷性场地.渑池至西安段6个浸水试验场地最大自重湿陷量为10.4～160.3 cm,属于Ⅱ级～Ⅳ级自重湿陷性场地,黄土自重湿陷性基本服从自东向西逐渐增强的规律.自重湿陷性黄土下限深度,现场实测值一般小于取样计算值.浸湿范围、自重湿陷变形范围和裂缝发生范围,存在前者控制后者的关系.分段评价郑西客运专线沿线黄土湿陷性,提出地基处理深度、桩基负摩擦力设计深度及路基防排水宽度建议值.

Water Immersion Field Tests of Collapsibility of Loess Foundation of Zhengzhou-Xi'an Passenger Dedicated Line

Eight typical sites for water immersion tests of collapsibility of loess foundation were determined by combination of the distribution characteristics of loess along the Zhengzhou-Xi’an Passenger Dedicated Line.The test results show as follows: The two water immersion test sites in the section between Zhengzhou and Mianchi exhibit the maximum self-weight collapse settlement of 0.47 cm to 2.65 cm,belonging to class Ⅱ of non self-weight collapsible sites;the six water immersion test sites in the section between Mianchi and Xi’an exhibit the maximum self-weight collapse settlement of 10.4cm to 160.3 cm,belonging to class Ⅱ to class Ⅳ of self-weight collapsible sites;self-weight collapsibility of loess basically obeys law of gradual strengthening from east to west;for the low-limit depth of self-weight collapsible loess,the values measured at sites are generally less than the calculated values of samples;there is a relationship of the former controlling the latter in sequence with regard to the immersion area,scope of self-weight collapse deformation and range of cracks occurrence.The loess collapsibility of the Zhengzhou-Xi’an Passenger Dedicated Line was evaluated by sections and the foundation treatment depth,the design depth of negative friction of pile foundation and the widths of roadbed waterproof and drainage are recommeded