After the excavation of abutment slope, the stress redistributed and the rock mass quality degradation damaged. According to fore-and-aft change of stresses for excavation, the authors divided excavation area and chose suitable mechanical parameters of rock mass for different excavation area. We used theory and methods of unloading rock mass mechanics and used elastic-plastic viscous damage mechanics model to give 2-D finite element analysis of stress and strain for typical profiles. And then we analyzed the changes of stress and deformation of the slope at nature and unloading conditions, analyzed deformation and stability at different reinforcement areas of the slope to choose reasonable reinforcement area. Strengthening plans of rock mass are analyzed and compared to choose reasonable reinforcement plan. The research results herein can offer beneficial reference for the design and the construction engineers.

There are rich resources in Central and South America, and mining products export plays an important role in the regional economic development. In this paper, the mining products trade information of more than ten years in Central and South America is collected, and then the authors point out that a "diversified export" strategy has been implemented by Central and South America in recent years for reducing the dependence on the economy of the United States, and the export of Central and South America is continuously rising to China but declining to the United States because they are benefited from the great demands of China's development on resources. However, along with the development of the industrialization in the countries of Central and South America, increasingly more resources will be consumed in this region. Therefore, some Central and South American countries will reduce their energy and mining products exports in the future in the condition of meeting their own needs.