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Initial damage often exists in the concrete piers of bridges in service. In this paper numerical analysis was used to study the seismic strengthening behavior of concrete bridge piers with different bending damage degrees, including seismic forces, pier top displacements, steel bar strain and energy dissipation, in order to obtain the strengthening demand to repair the damage piers. The results showing that: initial bending damage reduced the seismic force, increased the pier top displacements and the steel bar strain. After strengthening the pier top displacements and steel bar strain at the pier bottom decreased, energy dissipation increased, and the anti-seismic properties of damage piers effectively recovered, but the increase of the seismic force might make new plastic-hinges out the strengthened area. At last according to the mechanics properties the strengthening demand under different bending damage degrees was given.

The British emergentists have their pros and cons in the discussion of emergence. They succeeded in expressing the basic characteristics of emergence, but failed to explain how and why a property became emergence. So, the main subject of studying emergence is to explore the dynamics at present. This article redescribes the concept of emergence and proposes the concept of dynamics of emergence to explain how emergence comes into being. The dynamics of emergence can be divided into two parts: micro-dynamics and macro-dynamics. The former deals with the emergence coming from the interaction of pre-existing components of a system through their local interaction, bifurcation and iterative effect going to global pattern, while the latter discusses what the macro conditions and environments of emergence are, how systems adapt to the environment and how the environment selects systems at the edge of chaos. This article also points out that the dynamics of emergence has important implication in the research of organizations. Copyright © 2007 John Wiley & Sons, Ltd.