| 摘要 |
<p>The invention refers to an improvement in the construction of segmental spans such as bridges and similar structures by the method known as "step-by-step" consisting in mounting segments or modules in succession at the end of a cantilever span section already erected. In accordance with this improvement, each module is moved in the decking parallel with its width as far as a stand-by position, then lifted by an arm which is pivoted a quarter of a turn about a vertical post located beside the module and inboard of the span section and resting on it by two beams. The module is next lowered and is in the erection position.</p> |
