黄土湿陷性分布不连续对湿陷变形的影响研究  

Influence of discontinuous distribution of collapsible loess on its deformation

作　　者：郑建国[1] 邓国华 刘争宏[1] 陈冉升[1] 范寒光 李开超[1] 

机构地区：[1]机械工业勘察设计研究院,陕西西安710043 [2]西安市地下铁道有限责任公司,陕西西安710018

出　　处：《岩土工程学报》2015年第1期165-170,共6页Chinese Journal of Geotechnical Engineering

摘　　要：分析导致湿陷量计算值与实测值差异的原因对黄土湿陷性的准确评价具有重要作用,目前相关研究的深度和系统性还不足。以西安黄土塬区的黄土现场试坑浸水试验为依托,采用数值计算手段,对湿陷土与非湿陷土不同比例、排列方式和湿陷程度下土体的湿陷变形特征进行了对比研究,揭示了黄土中湿陷土分布不连续对湿陷变形产生的抑制作用是导致湿陷量计算值和实测值差异的重要原因之一。当黄土体中湿陷土单元和非湿陷土单元分布越杂乱,非湿陷土单元所占的比例越高时,这种抑制作用越明显;而湿陷土单元的湿陷程度对抑制作用的影响相对较弱。在计算湿陷量时,应考虑黄土湿陷性不连续效应的影响,并在工程实践中逐渐积累反映这种效应影响的经验数据。Investigating the difference between the calculated and measured values of the collapsible settlement is useful and necessary to accurately evaluate the loess collapsibility. Although the difference has been noted by many researches, it has not yet been examined deeply and systematically. Based on the results of two field loess immersion tests in Xi'an loess tableland area, the numerical method is used to compare the collapsible deformations of loess foundation with different proportions and arrangements of collapsible and non-collapsible soils as well as with different collapsible degrees of collapsible soils. The results reveal that the inhibition effect on collapsible deformation, which is caused by the discontinuous distribution of collapsible loess, is one of the main reasons for the discrepancy between the calculated and measured values of the collapsible settlement. In addition, this inhibition effect is more significant for the cases with more random distribution of collapsible and non-collapsible soils, or with higher proportion of non-collapsible soils. Through comparison, the impact on the inhibition effect caused by the collapsible degree of collapsible soils is not very strong. The inhibition effect should be taken into account in calculating the collapsible deformation, and the related data should be collected and summarized in future engineering practice.

关 键 词：湿陷性黄土 试坑浸水试验 湿陷变形 数值计算 

分 类 号：TU444[建筑科学—岩土工程]