China's high-speed railway carrying hundreds of tons, is the pier hollow or solid? The answer is not as imagined
As China builds super steel girder bridges capable of carrying hundreds of tons of high-speed trains, foreigners have begun to wonder: Are the piers of those bridges hollow or solid? In fact, these piers are not solid structures as people imagined, but are mostly hollow, so why does China use these bridges with hollow piers as passages for high-speed rail? Aren't you afraid that something will go wrong with them?
The picture shows a large road-rail dual-use bridge
Although the high-speed rail train looks heavy, its weight is actually very light compared to those freight trains with a single train of 10,000 tons or tens of thousands of tons. Everything strengthens itself to ensure that the bridge can withstand the huge weight of those super-heavy trains. Under this premise, how to ensure the cost-effectiveness of the high-speed railway bridge itself has become a matter that China must consider when building a high-speed railway special bridge.
The picture shows the railway bridge under construction
Therefore, under the premise of meeting the load of high-speed trains, China needs to concentrate more resources on reducing the cost of bridges, the weight of bridges, and the ability to cope with local climate environment and various conditions, just like using bridges for high-speed railways in China Most of the bridge piers are designed to be hollow, which, in a sense, is one of a series of measures to control costs and strengthen the bridge's adaptability to other environments.
Because compared to solid concrete-steel composite piers, hollow piers first have lower construction costs and also lower ground pressure, which also means lower foundation costs, especially in those areas where land settlement is likely to occur. In some areas, the decrease in the weight of the bridge itself means that the possibility of bridge settlement is reduced to a certain extent, which also means that when China builds high-speed rail bridges in these areas, the cost that needs to be invested in the foundation will also be reduced. Allowing China to focus more of its budget on improving the performance of other aspects of the bridge: like large shock absorbers between the pier and the bridge deck, or increasing the density of steel bars in the pier structure to improve the resistance of concrete composite piers. Compared with the question of whether the pier is solid or not, the tensile performance is obviously more important than strengthening the strength of the pier.
The picture shows the railway bridge in China
If the situation requires, China will not cut corners on composite steel composite concrete piers, such as those concrete piers with relatively slender cross-sections, due to their insufficient cross-sectional area, it is necessary to ensure the thickness of the entity to ensure its own strength to support high-speed rail bridges. It can resist damage caused by accidental impact, so China will not cut corners on such relatively slender piers.
In fact, before the construction of the bridge, the engineers will carefully design and think about the piers, determine the upper limit of the strength that the bridge needs to withstand when the train passes by, and what kind of damage will be caused to the bridge by the harsh environment. Under the premise that the bridge can effectively withstand the heavy pressure of trains and the surrounding harsh environment causes damage to the bridge, cost control has become one of the most important factors in bridge design and construction. Bridge piers, or the use of thinner box girder, will bring benefits to the construction of high-speed rail bridges in China, compared to using solid structures to strengthen bridge structures.