黏土地层盾构掘进速度对地表沉降影响研究

对盾构掘进速度的控制是盾构施工控制的重要环节，但针对盾构掘进速度与地表沉降关系的研究较少，文章以常州地铁2号线盾构区间施工为背景，分析了常州黏土地层下盾构掘进速度对表沉降的影响特点。通过对其地表监测数据的整理分析，结合盾构掘进施工日志，提出一种可对同步注浆、二次注浆、土舱压力、盾构掘进速度等进行定量分析的数值模拟方法，设计模拟工况对盾构全过程进行模拟研究，得到STEP计算步数与盾构掘进速度之间的对应关系，建立常州黏土地层下盾构掘进施工的掘进速度造成地表沉降预测曲线。研究结果表明：掘进速度较快时其造成的地表沉降更小，且当掘进速度在20～50mm/min时利用数值模拟得到黏土地层下掘进速度v—地表沉降h关系的预测曲线：h=6.5/{1+86.2［(v-19.5)/27842.7］0.464}，其预测效果较好。

Influence of shield driving speed on ground surface#br#settlement in clay layers

Shield tunneling speed is an important part of shield construction control, but there are few studies on the relationship between shield tunneling speed and surface settlement. This paper analyzes the construction of shield tunneling under the Changzhou clay layer under the background of Changzhou Metro Line 2 shield tunnel construction and characteristics of the influence of speed on surface settlement. Through collating and analyzing the surface monitoring data and combining with the shield tunneling construction log, a numerical simulation method that can quantitatively analyze synchronous grouting, secondary grouting, earth cabin pressure, shield tunneling speed, etc.is proposed to design the simulation Under the working conditions, the whole process of shield tunneling was simulated and researched, and the correspondence between calculation steps and shield tunneling speed was obtained, and the ground subsidence prediction curve caused by the tunneling speed of shield tunneling in the clay layer in Changzhou was established. The research results show that the surface settlement caused by the faster driving speed is smaller, and when the driving speed is 20～50 mm/min, the prediction curve of the relationship between the driving speed and the surface settlement in the clay layer is obtained by numerical simulation: h=6.5/{1+86.2［(v-19.5)/27842.7］0.464}, the prediction effect is good.