循环荷载下滨海软土孔压发展规律试验研究

摘要

地铁行车荷载会使隧道周围土体中的孔隙水压力发生变化，进而致使土体发生变形，甚至产生不均匀沉降，对地铁安全产生很大威胁。因此，了解土体孔压在地铁行车荷载下的发展变化规律极为重要。笔者基于 GCTS 空心圆柱测试系统对滨海软土进行试验，研究循环振动荷载作用下软土的孔隙水压力发展变化规律；同时分析荷载幅值、振动频率及土体围压对孔隙水压力的影响。试验结果表明：土体中孔隙水压力的增长规律表现为快速增长、缓慢增长、平稳三个阶段；并且孔压随振动次数、循环振动荷载幅值和围压的增大而增大，但增大幅率不同，随加载频率的增大而减小。%The subway vehicle load will make the pore water pressure in soil around the tunnel change,thus causing soil deformation,even producing uneven settlement.It’s a great threat to the subway safety,so understanding the develop-ment rule of the pore pressure of soil under the subway vehicle load is very important.This paper is based on GCTS hollow cylinder testing system to test coastal soft soil,to study the development rule of the pore water pressure of soft soil under cyclic vibration load and analyze the influence of load amplitude,vibration frequency and confining pressure of soil to the pore water pressure.The results show that the growth regularity of pore pressure in soils is characterized by three phases including rapid growth,slow growth and smooth growth,and pore pressure will increase with the increase of number of vibration,cyclic load amplitude of vibration and confining pressure with different rate.On the contrary,the pore pressure will decreases with the increase of loading frequency.