岩体隧道非线性地震响应分析

发布时间：2018-09-05 20:53

【摘要】：日本阪神、台湾集集和汶川等地震的震害调查表明,隧道结构的破坏主要是由地震动引起的岩体变形和断层错动所致。因此,开展岩体隧道地震响应特性的研究具有十分重要的理论和实际意义。岩体隧道的地震响应本质上是一种近场非线性波动问题,既受近场地震动的控制,又受复杂地形地貌和工程场地地质的影响,表现出显著的地形、断层、空间非一致和材料非线性等效应。本文基于近场波动有限元方法,对岩体隧道的地震响应开展相关研究。主要内容简要概括为如下两个方面:1.在近场波动有限元方法的理论框架内,开展了岩石材料本构关系及地震动输入方法两方面的理论研究。(1)针对岩石材料非线性力学行为,基于应变等效假设及有效应力概念的连续介质损伤力学理论,结合非线性统一强度理论模型,建立了一种考虑围压效应的三维弹塑性损伤本构模型。构建的本构模型与岩石三轴试验数据吻合良好,可很好地模拟岩石材料的围压效应及刚度退化行为。(2)针对地震动输入,结合黏弹性人工边界,建立了二维、三维半空间均质场地及三维半空间含断层场地条件下的平面波倾斜输入方法,并提出了地震动垂直输入的一种简化输入方法。对比了地震动波动输入和振动输入的区别,建立了一种考虑侧边界自由场影响的振动输入方法。2.基于近场波动有限元方法,研究了岩体隧道洞口段、长大隧道洞身段、节理偏压隧道及跨断层隧道的地震响应特性和反应规律。(1)结合建立的岩石三维弹塑性损伤本构模型,开展了隧道洞口段非线性地震响应分析,揭示了输入地震动的振动方向对隧道洞口地震响应的影响规律。(2)基于建立的三维半空间均质场地的地震动倾斜输入方法,研究了地震动SH波、P波及SV波以不同角度入射时长大型隧道的地震响应特性,探明了隧道轴线变形及横截面变形与地震动入射角度之间的关系。(3)基于岩石节理模型,研究了节理偏压隧道的地震响应特性,揭示了节理偏压隧道的地震破坏模式,探讨了地震动入射角度和节理倾斜角度对隧道地震响应的影响规律。(4)基于建立的三维半空间含断层场地的地震动输入方法,模拟了跨断层隧道的地震响应特性,初步探讨了入射角度、断层宽度和断层性质等参数对跨断层隧道地震响应特性的影响。
[Abstract]:The earthquake damage of Hanshin, Taiwan Jiji and Wenchuan earthquakes in Japan shows that the damage of tunnel structure is mainly caused by rock deformation and fault dislocation caused by ground motion. Therefore, it is of great theoretical and practical significance to study the seismic response characteristics of rock tunnel. The seismic response of rock mass tunnel is essentially a kind of near-field nonlinear wave problem, which is not only controlled by near-field ground motion, but also affected by complex terrain and geomorphology and engineering site geology. Spatial inconsistency and material nonlinearity. Based on the near-field wave finite element method, the seismic response of rock tunnel is studied in this paper. The main contents are summarized as follows: 1. Within the theoretical framework of the near-field wave finite element method, the constitutive relations of rock materials and the input method of ground motion are studied theoretically. (1) the nonlinear mechanical behavior of rock materials is studied. Based on the strain equivalent hypothesis and the concept of effective stress, a three-dimensional elastic-plastic damage constitutive model considering the confining pressure effect is established by combining the nonlinear unified strength theory model with the continuum damage mechanics theory. The constitutive model is in good agreement with the rock triaxial test data, and can simulate the confining pressure effect and stiffness degradation behavior of rock materials very well. (2) for the input of ground motion and the viscoelastic artificial boundary, a two-dimensional model is established. The oblique input method of plane wave under the condition of homogeneous ground in three dimensional space and fault site in three dimensional half space is presented. A simplified input method for vertical input of ground motion is proposed. In this paper, the difference between wave input and vibration input is compared, and a vibration input method .2. considering the influence of lateral boundary free field is established. Based on the near-field wave finite element method, the seismic response characteristics and response laws of rock mass tunnel opening section, long tunnel section, jointed bias pressure tunnel and cross-fault tunnel are studied. (1) the three-dimensional elastic-plastic damage constitutive model of rock is established. The nonlinear seismic response analysis of tunnel entrance section is carried out, and the influence of the vibration direction of input ground motion on the seismic response of tunnel entrance is revealed. (2) based on the 3D semi-space homogeneous ground motion input method, The seismic response characteristics of large tunnels with different incident angles of SH wave P and SV wave of ground motion are studied. The relationship between tunnel axis deformation, cross-section deformation and incident angle of ground motion is investigated. (3) based on rock joint model, In this paper, the seismic response characteristics of jointed bias pressure tunnel are studied, and the seismic failure mode of joint bias pressure tunnel is revealed. The influence of incident angle of ground motion and tilt angle of joint on seismic response of tunnel is discussed. (4) based on the method of ground motion input with fault in 3D half-space, the seismic response characteristics of cross-fault tunnel are simulated. The influence of incident angle, fault width and fault properties on seismic response of cross-fault tunnel is discussed.
【学位授予单位】：北京工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U452.28

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