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Columnar jointed basalts (CJB) are featured by the joint network of discontinuities, which is hard for geotechnical design and construction. Therefore, investigating the mechanical behaviors of CJB is significant for the long-term use of the engineering structures. In this paper, field research studies, such as the rigid bearing plate tests and acoustic tests, were employed, to obtain the deformation modulus and the acoustic velocity of columnar jointed basalts, and the formula expressed by deformation modulus and acoustic velocity was then established, which would be a useful guidance for the site operation. Based on the monitoring and testing data of CJB, several numerical simulation models with different joint angles and weak thickness were built to further discuss the mechanical behaviors of CJB. The numerical simulation results show that the joint angle of 30° ∼ 60° presents weak antipressure abilities, for the shearing slipping force and interformational sliding are remarkable in them. Besides, the small material property difference is helpful for the compressive strength of rock masses. After adopting the most unfavorable joint angle and width to model the tunneling process in CJB, it suggests that it is easily damaged along the directions of rock joints in CJB when constructing in tunnels.

A series of uniaxial compression tests are carried out firstly to confirm the reasonable surrounding rock parameters. Then building up the finite element analysis models of the horseshoe tunnel subjected to the seismic loads. The tunnel buried in different geological conditions, like the different plane angles between tunnel and fault fracture zone (e.g. 0°, 30°, 60° and 90°), different width of the fault zone (e.g. 1 m, 0.5D, 1.0D, 1.5D, 2.0D) (D is the tunnel width). The paper mainly discusses the dynamic stress concentration factors and damage mode on the horseshoe tunnel. Based on the experimental and numerical results, analyzing the distribution of dynamic stress concentration and damage mode on the tunnel, it can be concluded that the tunnel crossing fault fracture zone with the plane angle of 60° and the width of 1.0D are more hazardous, whose vertical convergent deformation, equivalent plastic strain (tensile), tensile damage and the slipping displacement of the fault are in the high level, when compared with other geological conditions simulated in the numerical analysis.

In this paper, we use China’s 1986-2008 data to make an empirical analysis on the interrelationship between trade openness, economic growth and the structural change of labor-intensive industries by using simultaneous equation models and a VAR model. Our empirical study leads to the three conclusions. First, trade openness has accelerated economic growth, though with some negative impact on the development of labor-intensive industries; Second, economic growth has had a positive effect on trade openness, but again negatively impacted the development of labor-intensive industries. Third, the expansion of labor-intensive industries has had negative effects on both trade openness and economic growth. Methodologically we rely on the transformation theory of industrial structure as an analytical framework to empirically study these three paradoxical outcomes. We introduce the three variables: trade openness, economic growth and the change of labor-intensive industries, as dependent as well as independent variables into our empirical models. And then we use technological progress, the share of secondary industries to GDP, total employment and investment ratio as control variables in order to test the robustness of the empirical results. In addition to explaining the factors responsible for changes in labor-intensive export industries we also provide two policy implications: First, labor-intensive industries should be scaled down to improve the efficiency of resources allocation. Second, China should timely transform its industrial structure of the export sectors from the one that is dominated by labor-intensive industries to the one that is dominated by capital (technology)-intensive industries so as to induce the export sectors to move in the direction favorable to the transformation of China’s present outward pattern of economic development.