盾构隧道开挖引起的深层土体沉降槽宽度参数取值分析

Analysis of the Parameter Values for Settlement Trough Width Induced by Shield Tunnel Excavation in Deep Soil

为了研究盾构开挖引起的深层土体沉降槽形态的变化规律,对既有的深层沉降经验公式进行总结,根据收集的21组黏土地层、20组砂土地层和8组卵石地层的现场实测和模型试验案例,对沉降槽宽度参数K(z)取值进行反演分析。研究得出,在任意地层中,使用双曲线形式和幂函数形式的经验公式都能较好地描述隧道开挖引起的沉降槽宽度参数K(z)随埋深比的变化趋势,在黏土和砂土地层中各经验参数的建议值分别为c=0.323、0.197,n=0.479、0.456;卵石地层中,沉降槽宽度参数与埋深比呈简单的线性关系。

To investigate the variation patterns of the deep soil settlement trough shape caused by shield tunnel excavation,existing empirical formulas for deep settlement were summarized.Based on the collected field measurements and model test cases—21 groups for clay,20 groups for sandy soil,and 8 groups for gravel—the settlement trough width parameter K(z)was analyzed through back-calculation.The findings indicate that in any type of stratum,both hyperbolic and power function empirical formulas can effectively describe the trend of the settlement trough width parameter K(z)with the depth ratio.The recommended empirical parameter values for clay and sandy soil are c=0.323、0.197,and n=0.479、0.456,respectively.In gravel layers,the settlement trough width parameter shows a simple linear relationship with the depth ratio.