| 摘要 |
<p>The construction of temporary bridges is aided by the use of two gantries. Each gantry consists of two columns (2) made of steel I sections mounted on feet (1). Each column is fitted with a jack (21) to raise or lower a cross-beam (9). This cross-beam is hollow and slides over beams (8) which project horizontally from each column (2). The deck sections of the temporary bridge are attached to the underside of the cross-beam (9). The lower edges of these deck sections are supported by brackets (11a,b) which are attached to guides (3) which slide on the columns (2). The design of the cross-beam enables the distance between the columns to be adjusted to suit the size of the deck sections.</p> |
