1. Objects of Structural Reinforcement and Retrofit Project

There are two types of buildings that need to be retained and structurally reinforced and reconstructed:

(1) Existing historical buildings;

(2) Existing industrial and civil buildings

(1) Existing historical buildings;

1) Cultural relics and buildings

The reinforcement of cultural relics should be based on the principle of repairing the old as before, and try to be faithful to the original environment, style, internal decoration, and original structure. But for the concealed part, considering the needs of earthquake resistance and durability, some modern materials and modern structural methods can be used.

2) Historic buildings

The protection and renovation of such buildings should be faithful to the original environment and style, especially the original facade modeling style is strictly retained. This type of building is often constructed in an early age and has been designed for a long time. Moreover, earthquake resistance and fire protection were not considered at that time, the durability standard was too low, and the structural safety was insufficient.

(2) Existing industrial and civil buildings

For existing industrial and civil buildings, it is necessary to prevent existing buildings without quality problems from being demolished. Moreover, the renovation and reinforcement of building structures are vigorously promoted, so that many existing buildings are reborn through renovation, so that they can prolong their life and far exceed their service life.

2. The content of the structural reinforcement and retrofit project

1) Structural transformation caused by changes in the functional layout of buildings

2) Structural transformation caused by translation, tilt correction, and layer increase

3) Structural transformation caused by enhancing the seismic performance of buildings

4) Structural transformation caused by improving the durability of the building

The durability of a structure refers to a structure that has undergone normal design and normal construction, and is used normally in the designed environment, without expensive maintenance and reinforcement, and can reach the level of design service life while maintaining the intended use function.

5) Structural transformation between building groups

In addition to the structural transformation of individual buildings, new structures are sometimes added between several monomers to change their architectural functions. Such as adding elevators, adding fire-fighting stairs, adding gate towers, adding rain sheds, adding flyovers, adding podiums, setting up corridors, filling inner courtyards, etc.

6) Structural transformation caused by building modelling and beautification

The external wall or external infill wall can be reconstructed by adding buttresses, waist lines, pilasters or other pick-out components. The external wall materials can also be replaced to improve the thermal insulation performance of the external wall. The “flat to slope” roof or roof greening can also cause structural transformation.

7) Structural transformation caused by the rebuilding of "unfinished buildings"

When some “unfinished buildings” are rebuilt, new owners often make many new changes to the original design based on economic and operating results, and there are many changes. Some buildings need to increase the storey, but also expand the span (the outer surface layer is selected to expand the usable area), and the internal entrance hall space (column and broken beam) must be modified. Although this kind of "unfinished building" is unfinished, its design and construction are relatively recent, the original structure is exposed, quality inspection is convenient, and it is easier to renovate than old buildings. The owner hopes to be "reborn", and the characteristics of renovation projects are often "complex content, large scale, and significant benefits".