›› 2017, Vol. 31 ›› Issue (5): 594-598.

• 工程实录 • 上一篇    下一篇

地下水位变化对黄土地基强度的影响及机理探讨

雅如文   

  1. (宁夏建筑设计研究院有限公司,银川 750002)
  • 收稿日期:2017-08-17 修回日期:2017-08-24 出版日期:2017-10-20 发布日期:2017-10-29
  • 作者简介:雅如文(1978-),男,工程师,研究方向为土的工程性质、地基处理等。

Effect of Groundwater Fluctuation on the Strength of Collapsible Loess

YA Ruwen   

  1. (Ningxia Building Design and Research Co., Ltd., Yinchuan 750002)
  • Received:2017-08-17 Revised:2017-08-24 Online:2017-10-20 Published:2017-10-29

摘要: 根据对宁夏吴忠市红寺堡区某黄土建设场地两次工程勘察,考虑地下水位变化对地基强度的影响,分别采用标准贯入试验和室内固结试验对地基土的强度进行评价,并从微观方面对含水量变化引起黄土地基强度改变的机理进行理论分析,结果表明:当地下水位升高时,地表以下固定深度范围内土体的标贯击数降低,土体强度明显下降;饱和黄土的压缩系数较非饱和黄土高;当土体的饱和度增加,颗粒的表面张力、基质吸力以及粒间胶结力、摩擦力均呈现下降趋势,因此在考虑黄土地基的强度时不仅需要考虑黄土的湿陷性,还应注重土体的遇水软化问题。

关键词: 黄土, 湿陷性, 含水量, 标准贯入试验, 固结

Abstract: This paper presents the geotechnical investigation results of the collapsible loess soil underneath the proposed Second Elementary School site of Irrigation District in Town of Tianyangshan, Wuzhong City of Ningxia Autonomous District. The effect of the groundwater fluctuation on the strength of the collapsible loess throughout the standard penetration test (SPT) and laboratory tests. The moisture content in the loess soil was closely monitored. The results indicate that, when the groundwater raise, the SPT blow count in the soil decreases and the soil strength significantly reduces. The compressibility coefficient of saturated loess is higher than that of nonsaturated sample. When the degree of saturated increases, the surface tension among soil particles, matric suction and cementation among soil particles reduce accordingly. In the practical design, not only the collapsibility of the loess should be aware but also the soften of loess soil when it is wetted.

Key words: Loess, Collapsibility, Moisture Contents, Standard Penetration Tests, Consolidation