Today most simple beam bridges are strengthened by a truss, which is based on the triangle. Diagonal beams has extended between the hori zontal and vertical beams give support against both compression and tension.

• 今天，大多数简支梁桥都用三角形的桁架加固。位于水平梁和垂直梁之间的对角梁承受压力和拉力。