真空加固前后软土工程地质性质研究

借助X-射线、扫描电镜及计算机图像处理等技术，对海积软土真空预压加固前后的结构特征进行定量分析，并结合室内试验，对比研究土体微观结构和工程性质的变化，探讨真空预压加固的机理。研究表明真空预压加固效果明显，软土工程性质得到改善。加固前软土的微结构以蜂窝状、团粒-絮凝状结构为主，大孔隙较多；加固后以团粒状结构为主，粒内和粒间孔隙变小；加固后结构单元体和孔隙未形成明显的定向性。这与堆载预压加固的结构变化显著不同。真空预压加固是在球应力即等向压力下固结。

Study on properties of soft soil in engineering geology around vacuum preloading

Analyzing quantitatively the structural features of soft soil from marine accumulation around vacuum preloading by means of X-ray,scanning electronic microscope and computer image processing technique,together with the experiment and comparing the changes of soft soil in microstructure and engineering properties,the authors studied the consolidation mechanism of vacuum preloading. The results show that an apparent consolidation effect can be obtained through vacuum preloading,and that the engineering properties of soft soil are improved.The microstructures of untreated soft soil mainly consist of honeycomb and granule-flocculent structures with more large pores.Whereas the microstructure of stabilized soil is marked by the ascendancy of the granular structure in which pores around grains become smaller.What's more,there isn't obvious directing property in building blocks and pores after consolidation,which is different in evidence from the results of preloading method,because consolidation in vacuum preloading occurs under the condition of spherical stress,namely isotropic stress.