Bridge Engineering Blog & Technical Insights

If notRubber bearing, or other types of bearings, but are connected into a whole, such as our two-span highway bridge above. So what are the problems? Or why do you have to put a bearing between the bridge deck and the pier?

Temporary supports are made by adding sand to two interlocking iron boxes, filled with sand to support them. After the continuous section is poured in place, the sand inside is released and the supports can be removed.

Application of Temporary Support for Sand Pipe

In daily engineering project construction, the principle and technology of sand tube temporary supports have been widely applied in continuous bridge construction. Temporary supports are very common in the construction of bridges with simple supports followed by continuous structures. Due to the advantages of flexible disassembly, high reliability, and relatively low price of this sand tube temporary support, it has certain value in practical applications, and many engineering projects have borrowed this form of support.

Precautions for Bridge Bearing Layout:

The arrangement of bridge supports is mainly determined based on the structural form and width of the bridge

A simply supported beam bridge is equipped with fixed supports at one end and movable supports at the other end Due to the small width of railway bridges, the lateral displacement of bearings is minimal, and generally only unidirectional movable bearings (longitudinal movable bearings) need to be installed. For highway T-beam bridges, the possibility of lateral movement of bearings needs to be considered due to the wide bridge deck; Namely, a fixed support is set on the fixed pier, adjacent supports are set as unidirectional movable supports that are horizontally movable and vertically fixed, while a longitudinal movable support (corresponding to the fixed support) is set on the movable pier, and multi-directional movable supports are set on the rest.

The construction of highway bridges in our country has entered the stage of stock maintenance. As of 2025, there are over 350000 bridges in service, of which approximately 40% have been in use for over 20 years. The lower structure, as the main load-bearing system of the bridge, includes piers, abutments, and foundation components. The lower structure material is mostly reinforced concrete material. Under the combined action of vehicle live load and bridge span dead load, a large number of diseases occur in the bridge structure during use, seriously reducing durability. According to the survey, the typical incidence of damage to lower components such as bridge piers, abutments, and foundations is as high as 62%. Therefore, it is necessary to study the mechanism and reinforcement methods of damage to the lower structure of bridges.