scholarly journals Dynamic Analysis of a Shallow Buried Tunnel Influenced by a Neighboring Semi-cylindrical Hill and Semi-cylindrical Canyon

Author(s):  
Xiaotang Lv ◽  
Cuiling Ma ◽  
Meixiang Fang

This paper provides a dynamic analysis of the response of a subsurface cylindrical tunnel to SH waves influenced by a neighboring semi-cylindrical hill and semi-cylindrical canyon in half-space using complex functions. For convenience in finding a solution, the half-space is divided into two parts and the scattered wave functions are constructed in both parts. Then the mixed boundary conditions are satisfied by moving coordinates. Finally, the problem is reduced to solving a set of infinite linear algebraic equations, for which the unknown coefficients are obtained by truncation of the infinite set of equations. The effects of the incident angles and frequencies of SH waves, as well as of the radius of the tunnel, hill, and canyon on the dynamic stress concentration of the tunnel are studied. The results show that the hill and canyon have a significant effect on the dynamic stress concentration of the tunnel.

2010 ◽  
Vol 163-167 ◽  
pp. 4265-4268
Author(s):  
Zhi Gang Chen

The dynamic stress concentration on quadratic and U-shaped cavities in half space, which are similar to the cross-section of the tunnels, is solved in this paper impacted by SH-wave. The analytical solution for the cavity in elastic half space is gained by the complex function method. In the complex plane, the scattering wave which satisfies the zero-stress condition at the horizontal surface can be constructed, the problem can be inverted into a set of algebraic equations to solve coefficients of the constructed scattering wave by least square method. For the earthquake-resistance researches, the numerical examples of the dynamic stress concentration around the quadratic and U-shaped cavities impacted by SH-wave are given. The influences of the dynamic stress concentration by the incident wave number and angle, the depth and shape of the cavity are discussed. It is showed that the interaction among the wave, the surface and the shallow buried tunnels should be cared in half space. In this situation, the dynamic stress concentration around the tunnel is greater obvious than the whole space.


2011 ◽  
Vol 199-200 ◽  
pp. 945-948
Author(s):  
Xiao Lang Lv ◽  
Dian Kui Liu

An analytic method is developed for dynamic stress concentration of a subsurface elastic cylindrical inclusion below a semi-cylindrical hill under SH-wave. And the dynamic stress concentration factor (DSCF) is given by complex variable function. During the solution, a standing wave and scattered wave displacement functions are constructed in different parts respectively. All of these displacement functions should satisfy the boundary conditions of each part. Employed to the boundary conditions around the elastic cylindrical inclusion, a series of infinite algebraic equations about the problem can be obtained. The calculating results of DSCF around the elastic cylindrical inclusion are plotted to show the effects of some parameters on DSCF.


Meccanica ◽  
2019 ◽  
Vol 54 (15) ◽  
pp. 2411-2420
Author(s):  
Guanxixi Jiang ◽  
Zailin Yang ◽  
Cheng Sun ◽  
Xinzhu Li ◽  
Yong Yang

2017 ◽  
Vol 24 (1) ◽  
pp. 299-311 ◽  
Author(s):  
Zailin Yang ◽  
Guanxixi Jiang ◽  
Haiyi Tang ◽  
Baitao Sun ◽  
Yong Yang

Based on complex function methods and a multipolar coordinate system, the scattering induced by a cylindrical cavity in a radially inhomogeneous half-space is investigated. Mass density of the half-space varies depending on the distance from the centre of the cavity while the shear modulus is always constant. The wave velocity is expressed as a function of radius vector and the Helmholtz equation is a partial differential equation with a variable coefficient. By means of a conformal mapping technique, the Helmholtz equation with a variable coefficient is transferred into its normal form. Then, displacement fields and corresponding stress components are deduced. Applying the boundary conditions, dynamic stress concentration factors around the cavity are obtained and analyzed. Typical numerical results are presented to demonstrate the distribution of dynamic stress concentration factors when influencing parameters are assumed.


2010 ◽  
Vol 452-453 ◽  
pp. 677-680
Author(s):  
Hong Liang Li ◽  
Hong Li

Multiple circular inclusions exists widely in natural media, engineering materials and modern municipal construction, and defects are usually found around the inclusions. When composite material with multiple circular inclusions and a crack is impacted by dynamic load, the scattering field will be produced. The problem of scattering of SH waves by multiple circular inclusions and a linear crack is one of the important and interesting questions in mechanical engineering and civil engineering for the latest decade. It is hard to obtain analytic solutions except for several simple conditions. In this paper, the method of Green’s function is used to investigate the problem of dynamic stress concentration of multiple circular inclusions and a linear crack for incident SH wave. The train of thoughts for this problem is that: Firstly, a Green’s function is constructed for the problem, which is a fundamental solution of displacement field for an elastic space possessing multiple circular inclusions while bearing out-of-plane harmonic line source force at any point: Secondly, in terms of the solution of SH-wave’s scattering by an elastic space with multiple circular inclusions, anti-plane stresses which are the same in quantity but opposite in direction to those mentioned before, are loaded at the region where the crack is in existent actually; Finally, the expressions of the displacement and stress are given when multiple circular inclusions and a linear crack exist at the same time. Then, by using the expression, an example is provided to show the effect of multiple circular inclusions and crack on the dynamic stress concentration.


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