地铁行车荷载作用下淤泥质黏土累积特性的试验研究

EXPERIMENTAL STUDY ON THE BEHAVIOR OF MUDDY CLAY UNDER SUBWAY LOADING

摘要: 中国上海地区地铁隧道一般位于第④层淤泥质黏土层中,在地铁行车荷载作用下隧道周围土体变形引起隧道轴线沉降,有些区段隧道轴线沉降量已超过20cm,引起了一系列环境地质问题。本文以上海第④层原状淤泥质黏土为研究对象,通过室内循环三轴试验,模拟地铁运营过程中产生的振动荷载,研究荷载作用下上海淤泥质黏土的累积应变、孔隙水压力及再固结后的Cu抗剪强度的变化规律,并分析加载过程中排水状态因素对土体特性的影响,得到一些重要结论,为上海地区地铁运营阶段行车荷载作用下土体变形,引起隧道轴线沉降的预测和防治提供了有价值地参考。

Abstract: During the cyclic triaxial test,the vibration loading produced by Shanghai underground subway running is simulated.The developmental law of acCumulated strain and pore water pressure of undisturbed muddy clay under this subway loading is studied.In addition,the effect of drained condition during cyclic loading on the properties of muddy clay is also analyzed.At the end of this paper,several important conclusions are presented,which are very useful to the predicting and controlling of tunnel settlement caused by subway running.