富水软弱地层盾构掘进引起长期沉降研究
发布时间：2018-07-14 21:18
【摘要】：采用盾构法修建城市地铁隧道时沉降分为施工期间沉降以及长期固结沉降两部分,如何预测和控制因盾构掘进引起的施工期间沉降和长期沉降,是盾构隧道施工所面临的一个重要问题。本文针对富水软弱地层的特殊性,结合苏州地铁2号线盾构隧道工程实例,通过实测分析、长期沉降预测和数值模拟,对隧道施工引起的长期沉降规律进行了深入的研究,主要进行了以下工作： (1)以实测数据为基础,研究施工期间沉降、二次补浆、土层性质等因素对盾构掘进引起长期沉降的影响,并总结了长期沉降规律。研究结果表明,地面长期沉降与施工期间沉降呈正相关关系,工后二次补浆可以显著减小地面的长期沉降；粘土对长期沉降影响较砂土大；工后经90-160天固结沉降发展,大部分建筑物倾斜率有0.03‰～0.6‰的增加。 (2)对盾构掘进引起的地面长期沉降进行理论预测,计算其最终沉降量及稳定时间。研究结果表明实测值与预测值两者吻合程度较好,富水软弱地层盾构施工期间沉降占预测总沉降量40%左右。预测地面沉降基本稳定需约1年时间,地面沉降最终稳定需约3年时间。 (3)基于三维数值模拟程序,对富水软弱地层盾构掘进引起长期沉降规律及其影响因素进行模拟分析。模拟表明,地表长期沉降也符合高斯曲线,沉降槽随时间发展变深变宽；渗透系数减小会显著增加沉降稳定所需要的时间,但对固结沉降量影响不大。
[Abstract]:The settlement of urban subway tunnel built by shield method is divided into two parts: settlement during construction period and long-term consolidation settlement. How to predict and control the settlement and long-term settlement caused by shield tunneling. It is an important problem in shield tunnel construction. In view of the particularity of water-rich soft stratum, combined with the practical example of shield tunneling of Suzhou Metro Line 2, the long-term settlement law caused by tunnel construction is deeply studied through actual measurement analysis, long-term settlement prediction and numerical simulation. The main works are as follows: (1) based on the measured data, the effects of settlement, secondary grouting and soil properties on the long-term settlement caused by shield tunneling are studied, and the long-term settlement law is summarized. The results show that there is a positive correlation between the long-term settlement of the land and the settlement during the construction period, the secondary grouting after construction can significantly reduce the long-term settlement of the land, the influence of clay on the long-term settlement is greater than that of the sandy soil, and the consolidation settlement develops after 90-160 days after construction. The slope ratio of most buildings is increased by 0. 03 鈥，
本文编号：2122981
[Abstract]:The settlement of urban subway tunnel built by shield method is divided into two parts: settlement during construction period and long-term consolidation settlement. How to predict and control the settlement and long-term settlement caused by shield tunneling. It is an important problem in shield tunnel construction. In view of the particularity of water-rich soft stratum, combined with the practical example of shield tunneling of Suzhou Metro Line 2, the long-term settlement law caused by tunnel construction is deeply studied through actual measurement analysis, long-term settlement prediction and numerical simulation. The main works are as follows: (1) based on the measured data, the effects of settlement, secondary grouting and soil properties on the long-term settlement caused by shield tunneling are studied, and the long-term settlement law is summarized. The results show that there is a positive correlation between the long-term settlement of the land and the settlement during the construction period, the secondary grouting after construction can significantly reduce the long-term settlement of the land, the influence of clay on the long-term settlement is greater than that of the sandy soil, and the consolidation settlement develops after 90-160 days after construction. The slope ratio of most buildings is increased by 0. 03 鈥，
本文编号：2122981
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