黑龙江地区渠道基土工程性质试验分析

黑龙江地区广泛分布有水敏性的分散性土和膨胀土，这些特殊土的存在对渠道工程的安全运行造成严重威胁。在分析土样物化性质和矿物成分的基础上，采用多种试验方法对龙头桥、蛤蟆通、引汤灌区渠基土的膨胀性、分散性和力学性质进行了研究，探讨了生石灰对土样分散性和膨胀性的处理效果。试验结果表明:3个灌区的土样均属于膨胀土，其中龙头桥灌区土样的膨胀性较强；蛤蟆通灌区的土样属于分散性土，引汤灌区的土样属于非分散性土；3个灌区土样的抗剪强度不高，黏聚力值为13.62~49.60 kPa，内摩擦角为1.0°~24.5°。由于龙头桥灌区土样的有机质含量很高，该灌区土样的黏聚力比其他两个灌区高，而内摩擦角比其他两个灌区低；低掺量下的生石灰对土样的分散性和膨胀性有较好的改性效果，该方法适用于处理不良渠基。

Experimental analysis of engineering properties of foundation soil of canal works in Heilongjiang area

The dispersive soil and expansive soil are widely distributed in Heilongjiang area which are sensitive with water. Those problematic soils can cause serious threat to canal engineering safety. Based on the analysis of physical and chemical properties and mineralogical composition, the expansibility, dispersivity and mechanical properties in Longtouqiao, Hamatong, Tangyuan irrigation canal were studied by swelling ratio tests, crumb tests, pinhole tests, double-hydrometer tests, pore water soluble cations tests, exchangeable sodium percentage tests and direct shear, and futher investigations on the treatment effect of expansibility and dispersivity with lime. The experimental analysis results indicate that, those soils have the expansive properties, and the Longtouqiao soils are the strongest among those soils. The Hamatong soil is the dispersive soil, but the others are not. The shear strength of the soil samples in the three irrigation areas is not high, the cohesions of soil samples in the Longtouqiao irrigation area are higher than others, which is between 13.62 and 49.60 kPa, and the internal friction angles are lower than others which is between 1° and 24.5°for high organic matter content from 12.3 to 15.3 g/kg. There were obvious modification effect with low lime, which could eliminate expansibility and dispersivity. This method could be used for the poor canal foundation treatment.