基于微结构试验分析的沉桩挤土效应研究

为进行软土中静压桩沉桩挤土效应机理分析,本文模拟桩周土受挤压过程,对软土试样进行室内压缩试验,以压缩时间为控制,分别取施压1、10、20、40、60、240、480、1440min后的试样进行微观结构试验;同时在现场取沉桩前后不同时间的桩周原状土样,平行进行微观结构试验。对试样SEM照片进行处理分析,得到了天津滨海软土在受压后不同时间和沉桩前后的土体孔隙微观结构参数的变化规律。通过对两次微结构试验对比分析,认识了沉桩挤土效应微结构变化规律,为进一步研究静压桩挤土效应机理和防治沉桩挤土效应提供了参考。

Study on Squeezing Effect Caused by Pile-driving in Soil based on Microstructure Test Analysis

For the research of driving effects of jacked pile in soft clay,compression tests are conducted to simulate the extrusion of soil around pile.Take compression time as guideposts,microstructure tests are conducted when the soil at different compression time:1min,10min,20min,40min,60min,240min,480min,1440min.Using onsite soil around pile at different time before and after pile driving,parallel tests are conducted.Through the analysis to SEM photos of soil which is from Tianjin marine soft soil,the variation behavior of microstructure parameters of soil pore is drawn at different time of compression and pile driving.By comparing the two tests,microstructure changing mechanism of pile driving effects is realized;references for the further research and control of pile driving effect are provided.