表面张力与接触角对膨胀土干缩开裂影响的试验研究

发布时间：2018-02-26 13:08

本文关键词： 悬滴法躺滴法表面张力接触角干缩开裂　出处：《岩土工程学报》2017年09期 　论文类型：期刊论文

【摘要】：用悬滴法对纯水、酒精溶液和肥皂水(表面活性剂)3种液体的表面张力进行测量,比较3种液体表面张力的大小;用躺滴法测量混有十八胺的两种土样的接触角。在此基础上,针对不同表面张力和接触角的膨胀土试样进行收缩开裂试验。试验结果表明:孔隙水表面张力和接触角对膨胀土的收缩开裂有重要影响。表面张力越小的试样,其最终收缩开裂裂隙度越小,但在裂隙发展阶段,脱湿时间相同时,孔隙水表面张力小的土样其收缩开裂裂隙度有可能大于表面张力较大的土样。增大土颗粒与孔隙水间的接触角可以很好的抑制膨胀土的收缩开裂,接触角越大,相同的脱湿时间下土体的收缩开裂裂隙度越小。减小孔隙水表面张力或增大接触角都会使土体中的弯液面曲率半径增大,从而减小土体中的基质吸力。接触角的增大还有可能使弯液面由凹变凸,基质吸力会因此消失,从而很好的抑制膨胀土开裂。
[Abstract]:The surface tension of pure water, alcohol solution and soapy water (surfactant) was measured by hanging drop method to compare the surface tension of the three liquids, and the contact angle of two soil samples mixed with 18 amine was measured by lying drop method. The shrinkage cracking test of expansive soil samples with different surface tension and contact angle is carried out. The results show that the surface tension and contact angle of pore water have an important effect on shrinkage cracking of expansive soil. The smaller the final shrinkage, the smaller the crack, but when the dehumidification time is the same, The shrinkage cracking crack degree of soil sample with small surface tension of pore water may be greater than that of soil sample with higher surface tension. Increasing contact angle between soil particle and pore water can restrain shrinkage and crack of expansive soil, and the larger the contact angle is, At the same time of dehumidification, the smaller the shrinkage crack degree of soil is, the smaller the surface tension of pore water is or the greater the contact angle is, the larger the curvature radius of curved liquid surface in soil is. The increase of contact angle may make the curved liquid surface from concave to convex, and the matrix suction will disappear, so as to restrain the cracking of expansive soil.
【作者单位】：云南农业大学水利学院;南昌航空大学土木建筑学院;
【基金】：国家自然科学基金项目(41662021,51209182,51408291)
【分类号】：TU443

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