Structural underpinning for structural reinforcement

The steel structure in this project inevitably has various defects and damages. Under the influence of load and environment, the material changes, resulting in the deterioration of macroscopic mechanical properties, steel structure engineering accidents. Tianjin structural reinforcement ensures the safety of the structure and prolongs the service life. Damaged parts must be replaced or strengthened. The replacement of these parts will cause huge waste and will affect the normal use of the structure.

Structural underpinning technology refers to the function transformation of the original load-bearing structure by changing the stress system to affect the building function, so as to obtain a more ideal use space. The underpinning methods of the structure are generally steel underpinning, reinforced concrete underpinning, frame supporting and so on. Underpinning technology refers to the inevitable passage of the city subway or underground tunnel under the building. In order to avoid demolition and reconstruction, ground buildings need piles to replace. The technology mainly includes the following steps: first, through the need to cut the building pile through the underground tunnel; Firstly, the upper load of partial pile foundation is transferred to a new pile foundation outside the tunnel by adopting a beam transfer layer near the cap, and the new pile foundation composed of underpinning beam and new pile is replaced. At the same time, in order to ensure that the underpinning structure will not crack and tilt after the broken pile and tunnel pass, the underpinning beam prestressed tensioning, jack prestressed, pile bottom grouting and other technologies are adopted. Pile foundation underpinning can be applied to many patent technologies such as small rock-socketed steel pipe cast-in-place pile and concrete interface connection technology. According to the stress characteristics of carbon fiber and bonded steel, it is particularly effective to strengthen flexural members or other tensile members such as beams and plates, but it is not appropriate to strengthen axial compression members or small bias members.