含淤泥质土地层中地铁施工 引起地表沉降及防治对策

随着大中城市地铁建设快速推进，在含淤泥质土等软弱土层的地区深入研究因地铁盾构掘进引起的地表沉降显得尤为重要。本文提出了一种能考虑多层地层分布情况的改进Peck经验公式方法，以武汉地铁2号线某区间为研究对象，分别运用提出的改进Peck经验公式方法和数值模拟软件Flac3D对该区段地表沉降情况进行了研究。计算结果表明软弱土层对于地铁施工引起的地表沉降量最为明显，数值分析结果与地表沉降实测资料吻合程度较高；提高软弱土层的抗剪强度参数有益于改善地铁施工引起的地层沉降情况。最后，本文针对研究区间的具体情况，提出了几点相应的软基处理防止地铁施工引起地表沉降的防治措施建议。

Study on Ground Settlement Caused by Subway Construction in Muddy Soil Layer and Its Countermeasures

With the rapid development of subway construction in large and medium-sized cities, the further study of the ground settlement caused by subway construction is particularly important in areas with silty soil and other soft soil layers. An improved Peck empirical formula method that can consider the distribution of multi-layered strata are proposed in this paper. A section of Wuhan Metro Line 2 is taken as the research object, the proposed improved Peck empirical formula method and the numerical simulation method via Flac3D software are both employed to study the ground settlement. The results show that the strata of soft soil contribute the most to the ground settlement caused by subway construction, and the numerical analysis results are in good agreement with the measured ground settlement data. Moreover, increasing the shear strength parameters of the soft soil layer is beneficial to improve the ground settlement caused by subway construction. Finally, several suggestions including treatment measures of soft base for the prevention of stratum subsidence have been proposed based on the specific circumstances of the research object.