基于增湿变形的渠道工程黄土渠基湿陷性评价方法

Evaluation method for collapsibility of channel engineering with Loess foundation based on moistening deformation

湿陷变形是黄土地区工程建设,特别是像渠道工程这样的行水建筑物必须面对的问题。我国目前实行的《湿陷性黄土地区建筑规范》(GB50025-2004)在工程等级标准、上覆压力选择和湿陷等级标准等方面存在不适合渠道工程的缺陷。本文依托新疆一大型引水渠道工程(设计流量215.9 m3/s,黄土深度达到30 m),从渠道工程的特点出发,提出了基于增湿变形的渠道工程渠基黄土场地的湿陷性评价方法,以弥补现有规范的不足。实例应用表明,该方法按照实际上覆压力和增湿变形等方面进行分析,具有既符合渠道工程实际,又可以充分考虑渠道工程防渗层作用的优势。

Collapsible deformation is a common problem for projects such as channel engineering in Loessregions. In China, the current practice of ＂Code for building construction in collapsible loess zone＂（GB50025-2004） has defects that not suitable for channel projects,especially on the aspects of standard for en-gineering classification, selection of overlying pressure and standard for collapsibility classification. Support-ed by a large diversion channel project（the design discharge is 215.9 m3/s,and the depth of Loess reached30m）, this paper proposed a new evaluation method for collapsibility of channel engineering with Loessfoundation based on moistening deformation, to compensate for the shortage of the existing specifications.The practical application shows that the proposed method has the advantages of complying with actual condi-tions of channel engineering and fully considering the effect of seepage control layer,according to the analy-sis of actual overlying pressure and moistening deformation.