高水压下大直径海底盾构隧道地震动力响应分析

发布时间：2018-01-07 06:17

本文关键词：高水压下大直径海底盾构隧道地震动力响应分析　出处：《北京建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：相比于越江隧道,海底隧道面临着更加显著的高水压、复杂地质条件问题,在地震安全有关方面有更高要求,而目前的隧道动力响应研究多集中在陆地隧道,对此考虑较少。本文借鉴邓肯-张E-B理论模型相关原理,运用FLAC3D软件自带的二次开发编辑平台对软件自带的摩尔库伦模型的相关函数进行修改,实现邓肯-张本构模型的开发,并运用于海底盾构隧道地震动力响应分析中。综合分析了不同水压对海底隧道的动力响应影响,并针对高水压下隧道穿越土石交界处和地质断裂带等情况进行了模拟计算,得到以下研究成果:(1)埋深一定时,地震波作用下水压的变化对隧道结构水平位移影响较大,位移峰值和第一主应力峰值都随水压的增大而增加,但与运用莫尔库伦模型的情况相比,水压增加时结构位移增长趋势变缓。这可能是因为在本文运用的邓肯-张(E-B)模型中,水压增大使围岩所承受围压增加导致土体的弹性模量增加,所以对隧道产生约束也相应增大,但约束效应的增加比率有所减缓。(2)隧道穿越土石交界处时,水压变化对结构的动力响应影响较大,随着水压的增加,位于软土区的结构地震位移峰值和应力峰值都随之增加。软土区土层条件的变化对结构动力响应有着较大的影响,随着土层弹性模量的减弱,土体弹性模量与岩石弹性模量差距越大,结构的位移峰值和应力峰值都随之增加,同时介质物理性质突变的影响范围也变大。(3)断裂带对结构的地震动力响应具有明显的影响。特别是在断裂带区域,结构动力反应较为剧烈,受地震波波动影响较大。而随着水压的增大,结构在断裂区的位移和应力都随之增大。沿着隧道轴向变化看,结构主应力峰值发生在岩石与土体的交界处,这主要是由于软土和岩石位移和变形错位差造成结构的剪切变形,产生大的应力变化,特别是结构的肩部和脚部,很容易发生破坏,应重点做好防护。
[Abstract]:Compared to the Yu Yue river tunnel, tunnel face high pressure is more significant, complex geological conditions, in terms of seismic safety have higher requirements, and the tunnel dynamic response of land concentrated in the tunnel, this is seldom considered. This paper use Duncan Chang E-B model theory related principle, modified using the correlation function two times the development of editing platform of FLAC3D software of Moore Kulun model software, to achieve the development of Duncan Chang constitutive model, and applied to seafloor seismic response analysis of shield tunnel. The comprehensive analysis of the effects of different water pressure on dynamic response of submarine tunnel, and the simulation calculation was carried out for high hydraulic pressure tunnel through the earth and the junction of the fault zone and so on, get the following research results: (1) a certain depth, influence of earthquake water pressure on tunnel structure horizontal displacement Large displacement and the first principal stress increases the peak stress with increasing the water pressure, but compared with the Kulun Moore model, the water pressure increases when the displacement of the structure growth trend slowed down. This may be because in the Duncan Chang (E-B) model, the pressure increase rock under confining pressure increase lead to the increase of elastic modulus of soil, so the tunnel restraint also increases, but the increase rate constraint effect slowed. (2) the tunnel through the embankment at the junction, the change of water pressure has great influence on the structural dynamic response, with the increase in water pressure, seismic displacement in soft soil area and the stress peak increased. Changes of soil conditions in soft soil area on the structure dynamic response has a greater impact, with the weakening of the elastic modulus of the soil, the elastic modulus of soil and rock elastic modulus, the greater the gap, the peak displacement of the structure And the peak stress increases, while the influence range of the physical properties of mutation is also larger. (3) fault zone has obvious influence on the seismic response of structures. Especially in the fracture zone, the structural dynamic response is more intense, the seismic wave influence. With increasing the water pressure, displacement of structure in the fracture zone and stress are increased. Along the tunnel axial variation, structure of main peak stress occurs at the junction of rock and soil, which is mainly due to the soft soil and rock displacement and deformation dislocation structure caused by poor shear deformation, resulting in large stress changes, especially the structure of the shoulder and foot that is easy to be destroyed, should focus on the door.

【学位授予单位】：北京建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U452.28

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