土与衬砌结构相互作用的隧道三维内源瞬态动力响应分析

发布时间：2018-11-25 17:03

【摘要】：实际工程中,地下衬砌结构可能受到内源瞬态荷载作用,如发生在2013年11月22日的黄岛石油管道爆炸,会对衬砌结构及其周围岩土介质造成严重破坏。为此,本文开展衬砌隧道内表面作用有内源瞬态荷载时,产生的应力波在隧道衬砌及周围岩土介质中的传播衰减规律,为地下隧道的抗爆减震设计提供理论依据。主要研究内容如下:(1)内源爆炸荷载作用下无限弹性空间中衬砌隧道的瞬态动力响应。采用Fourier变换和Laplace变换,推导出内源爆炸荷载作用下无限弹性空间中圆柱形衬砌孔洞的瞬态动力响应无量纲解答,利用Fourier和Laplace逆变换数值方法,计算分析内爆炸荷载产生的振动在衬砌和周围弹性介质中的分布和传播衰减规律。计算结果表明,爆源中心处衬砌和周围土体接触面处径向位移、径向应力、环向应力最大,向左右两侧迅速衰减,在5倍衬砌内径处衰减趋于零;接触面上径向位移、径向应力、环向应力时程曲线峰值爆源中心处最大,离爆源中心越远,峰值越小,且在t*=10时衰减趋于零。(2)内源爆炸荷载作用下无限饱和多孔介质中衬砌隧道的瞬态动力响应。采用Laplace和Fourier变换,提出一种在内源爆炸荷载作用下,饱和土体中圆形衬砌隧道的瞬态动力响应精确解答。基于Biot波动理论,将周围土体和衬砌结构分别看成饱和两相介质和弹性介质,推求了 Laplace和Fourier变换域内爆炸荷载作用下衬砌和周围饱和土体的动力响应解析解。利用Laplace和Fourier变换反变换的数值方法,进行了爆炸荷载作用下衬砌和周围土体的动力响应数值分析。结果表明:与简化的二维平面应变模型相比,基于三维模型得到的环向应力、径向位移和孔隙水压力较小;隧道的动力响应随时间而迅速减小,并随着与爆源距离的增加,而在径向和轴向上呈指数衰减。(3)隧道衬砌周围分别为弹性介质和饱和多孔介质时隧道动力响应的对比。假设饱和多孔介质的孔隙率n为0,将饱和多孔介质退化为理想弹性介质,获得了衬砌隧道周围为弹性介质时的衬砌隧道的动力响应解答,将衬砌隧道周围为弹性介质和饱和多孔介质时衬砌隧道的动力响应计算结果进行比较,对比分析表明,衬砌周围为弹性介质时衬砌隧道的动力响应值,如隧道衬砌的径向位移和切向应力较衬砌周围为饱和多孔介质时衬砌隧道的动力响应大。
[Abstract]:In actual engineering, the underground lining structure may be subjected to internal transient load, such as the Huangdao oil pipeline explosion on November 22, 2013, which will cause serious damage to the lining structure and its surrounding rock and soil media. Therefore, in this paper, the propagation and attenuation of the stress wave in tunnel lining and surrounding rock and soil media is carried out when the internal surface of lining tunnel has internal transient load, which provides a theoretical basis for the design of anti-explosion and earthquake mitigation of underground tunnel. The main contents are as follows: (1) transient dynamic response of lining tunnel in infinite elastic space under the action of internal explosion. By using Fourier transform and Laplace transform, the dimensionless solution of transient dynamic response of cylindrical lining holes in infinite elastic space under the action of internal explosion load is derived. The inverse transformation numerical method of Fourier and Laplace is used. The distribution and propagation attenuation of the vibration produced by internal explosion load in lining and surrounding elastic media are calculated and analyzed. The calculation results show that the radial displacement, radial stress and circumferential stress of the lining at the center of the explosion source and the interface of the surrounding soil are the largest, and the attenuation tends to be zero at 5 times the inner diameter of the lining. The radial displacement, radial stress, and circumferential stress on the contact surface are the largest at the peak explosion source center, and the farther away from the explosion source center, the smaller the peak value. And the attenuation tends to be zero at 10:00. (2) the transient dynamic response of lining tunnel in infinite saturated porous media under the action of internal source explosion. By using Laplace and Fourier transform, an exact solution to the transient dynamic response of circular lining tunnel in saturated soil under the action of internal explosion load is presented. Based on Biot wave theory, the surrounding soil and lining structure are regarded as saturated two-phase medium and elastic medium respectively, and the analytical solution of dynamic response of lining and surrounding saturated soil under blast load in Laplace and Fourier transform domain is derived. The dynamic response of lining and surrounding soil under explosive loading is numerically analyzed by using the inverse transformation of Laplace and Fourier transform. The results show that compared with the simplified two-dimensional plane strain model, the circumferential stress, radial displacement and pore water pressure obtained by the three-dimensional model are smaller. The dynamic response of the tunnel decreases rapidly with time, and decreases exponentially with the increase of the distance from the detonation source. (3) the dynamic response of the tunnel is compared with the elastic medium and saturated porous media around the tunnel lining. Assuming that the porosity of saturated porous media is 0, the saturated porous media is reduced to an ideal elastic medium, and the dynamic response solution of the lining tunnel is obtained when the lining tunnel is surrounded by an elastic medium. The dynamic response of lining tunnel with elastic medium and saturated porous medium is compared. The results show that the dynamic response of lining tunnel is elastic medium. For example, the radial displacement and tangential stress of tunnel lining are larger than that of tunnel with saturated porous media around the lining.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451

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