基于虚拟力法的盾构隧道施工扰动地层附加应力分析

发布时间：2018-04-23 20:15

本文选题：盾构隧道 + 分层效应　；参考：《岩土工程学报》2014年07期

【摘要】：目前针对盾构隧道掘进引起周围地层附加应力的研究较少,且既有成果一般均假定施工场地为均质土体。基于层状地基基本解,结合虚拟力法,建立了考虑分层效应的盾构隧道施工扰动地层附加应力的分析方法,重点研究了盾构施工正面附加推力、盾构与土体间掘进摩擦力引起的地层附加应力。结合上海典型分层地基工程实例,分析了盾构施工引起的附加应力分布规律,且与均质土体工况下的计算结果进行了对比研究,考察了地基分层效应对扰动地层应力场的影响。计算结果表明:盾构与土体间掘进摩擦力与正面附加推力引起的土体附加应力分布规律较为相似,靠近开挖面时附加应力衰减较快且影响范围一般较小,而远离开挖面时应力衰减明显变慢,在实际工程中要重视掘进摩擦力和正面附加推力造成的施工风险;此外,考虑分层效应与常规不考虑分层效应时的附加应力场有较大差别,在设计中应重视地基非均质性带来的影响。成果可为合理制定层状地基中盾构隧道施工对临近管道以及建筑物的保护措施提供一定的理论依据。
[Abstract]:At present, there are few studies on the additional stresses in the surrounding strata caused by shield tunneling, and the existing results generally assume that the construction site is homogeneous soil. Based on the basic solution of layered foundation and the virtual force method, the analysis method of additional stress in shield tunnel construction disturbed stratum is established, and the frontal additional thrust of shield tunneling is studied emphatically. Additional stress of stratum caused by friction force between shield tunneling and soil. Combined with typical layered foundation engineering in Shanghai, the distribution law of additional stress caused by shield tunneling is analyzed, and compared with the calculated results under homogeneous soil condition, the influence of stratification effect on disturbed formation stress field is investigated. The results show that the distribution of additional stress caused by the friction force between shield tunneling and soil is similar to that caused by frontal additional thrust, and the additional stress attenuation is faster and the influence range is smaller when it is close to the excavating surface. However, the stress attenuation is obviously slower when away from the excavating surface, and the construction risk caused by the friction force and the frontal additional thrust should be paid more attention to in the actual engineering, in addition, the additional stress field considering the delamination effect is different from that of the conventional one when the delamination effect is not taken into account. Attention should be paid to the influence of the heterogeneity of the foundation in the design. The results can provide a theoretical basis for the reasonable establishment of protective measures for adjacent pipelines and buildings in shield tunnel construction on layered foundation.
【作者单位】：上海理工大学环境与建筑学院;同济大学岩土及地下工程教育部重点实验室;中国矿业大学深部岩土力学与地下工程国家重点实验室;华东建筑设计研究院有限公司;
【基金】：国家自然科学基金项目(51008188) 同济大学岩土及地下工程教育部重点实验室基金项目(KLE-TJGE-B1302) 中国矿业大学深部岩土力学与地下工程国家重点实验室基金项目(SKLGDUEK1205)
【分类号】：U455.43;U452.1

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