景电工程干渠块石换填措施抗冻融效果评价

Evaluation on the Effects of Freezing-Thawing Resistance by Block-Stone Replacement for Main Canal in Jingdian Project

为解决景电工程干渠红砂土基础在地下水浅埋条件下冬季冻胀量大、暖季融沉滑塌严重的问题,对渠道基础采用块石换填的抗冻胀融沉方案。根据地下水埋深与渠基土冻胀、融沉强度的关系,得到冻土的本构方程,采用COMSOL有限元软件对换填前和换填后渠道衬砌的位移场和应力场进行了对比计算。结果表明:换填后的渠坡、渠底衬砌板法向位移最大值相对于换填前分别减小了53.8%、78.0%;换填后,渠道衬砌最大法向冻胀力和切向冻结力相比换填前分别减小了73.2%和82.8%,且整体分布更均匀。在地下水浅埋和土体遇水软化的水文地质条件下,块石换填渠道具基础有优良的抗冻胀融沉效果。

As a result of the largeamount of frost heave in winter and the serious collapse in spring which attributed to the shallow underground water table of arenosol’s foundation,a foundation replacement measure with block stone in the main canal of Jingtai irrigation was proposed for anti-frost heave and anti-thaw settlement.According to the relationship between groundwater depth and frost thawing sink strength of canal base,it got frozen soil’s constitutive equation and it calculated the displacement field and stress field of canal lining that before and after replacement of block stone by using the COMSOL finite element software.The results show that the replacement of canal slope,the canal bottom lining plate method to the maximum displacement value relative to replacement before are reduced by 53.8%and 78.0%respectively;after replacement,the maximum method to frost heaving force of lining and cut to a freezing stress compared to change before filling are reduced by 73.2%and 82.8%respectively and the overall distribution is more uniform.In the condition of shallow groundwater or soil softening encountering water,the effects of freezing-thawing resistance by the block-stone replacement measure for canal are excellent.