SiWIM Bridge assessement

Bridge applications

Bridge failures can threat lives and are thus unacceptable. Optimized assessment of existing bridges, particularly if they are old, deteriorated and suffering from reduced carrying capacity, requires as accurate inputs as possible. An effective option is to apply realistic, site-specific traffic loads and to calibrate the analytical model of the bridge according to the measured bridge response. SiWIM® system was designed to provide such information.

Growth in domestic and international commerce.

SiWIM® provides two types of essential information to improve bridge safety analysis. Firstly, it collects traffic data and secondly, it identifies the true behaviour of bridges (through influence lines and load distributions), a crucial parameter to convert properly traffic loads into load effects (axle loads into moments and shear forces).

To cater for the whole life-time of bridges, which is typically 75 or 100 years, the bridge design codes overestimate the traffic loading. In real life, the traffic loading is constantly increasing, and the structure itself is deteriorating. Thus, a 100-year old bridge will likely not pass a safety assessment based on a current loading standard. To overcome this, SiWIM® collects information about true traffic and converts it into the expected maximum load effects (figure left). These are typically much lower than the design. A simulation method for shorter bridges is provided with the SiWIM®, but any other analytical method benefits from the collected axle loads.


Bridges are critical components of any road or rail transportation system.
SiWIM® is an extremely efficient tool to optimize structural safety analyses and to reduce number of bridges that need to be rehabilitated. This not only saves money to the bridge owners and tax payers, but also mitigates road closures and, consequently, improves mobility and quality of life and has positive effects on safety of road users and workers and on the environment.