封闭气泡 meaning in English

captive air bubble
captured air bubble

In this paper , some aspects of vacuum preloading were studied as follows . vacuum consolidation test and load consolidation test were performed and compared for different kind of soil samples . after analyzing the results of tests , the four major mechanisms of vacuum consolidation were defined as : variation of capillary potential , drainage of sealed bubbles , vaporization and action of atmosphere pressure , in which , the action of atmosphere pressure is the most important factor
首先对不同土样进行了一系列室内真空固结和加载固结的对比试验，通过对试验结果的比较分析，明确了抽真空引起土样固结的原因，即抽真空作用会在四个方面对试样产生影响：毛细管势的改变、封闭气泡的排出、汽化现象及大气压的作用，而其中大气压的作用是最主要的。