粗颗粒盐渍土盐胀试验研究

Experimental Study on Salt Expansion of Coarse Particle Saline Soil

盐渍土盐胀的影响因素很多,但主要与地基土中盐的含量、水、温度及地基土的渗透性有关。前人关于粗颗粒盐渍地基土盐胀性的研究中,由于工作主要集中在室内,难以模拟现场地层的实际情况,因此,对于盐胀性的认知一直难以统一。本文通过室内盐胀试验、室内外对比试验、现场试验,并与规范对比研究认为:粗颗粒盐渍土,当渗透系数小于10-7,且地层干燥,Na2SO4含量达到盐渍土的界限含量(0.3%)时,就应对其进行盐胀性评价。同时试验结果显示,地基土在200 k Pa大压力作用下,盐胀量仍然非常明显。

The influencing factors upon salt-heaving properties of salty soil are a lot,but the primary are relate to the groundsill salinity、water、temperature、penetrability.The work of previous studies about salt heaving of coarse salty soil were indoors,it was dififcult to simulate the actual formation of the stratum,that resulted in different cognition about salt heaving.In view of indoor salt-heaving experiment、indoor-outdoor supplementary experiment、ifeld trial and comparative study with the speciifcation,the results show that：coarse salty soil,when the permeability coefifcient is less than 10-7,the formation is drying, Na2SO4 content of saline soil is 0.3%,it should carry salt-heaving evaluation. Meanwhile,experiment show that salt heaving under 200 kPa great pressure is still very obvious.