| 摘要 |
<p>According to the present invention, a tetragonal lattice girder for supporting an excavated surface of a tunnel comprises: an upper steel bar (100) extended along a tunnel; a lower steel bar (200) spaced at a predetermined distance from the upper steel bar (100) and extended along the upper steel bar (100); a fixing member (300) connecting the upper steel bar (100) and the lower steel bar (200) to be fixated; and a connection unit (500) extended connecting the upper steel bar (100) and the lower steel bar (200) and a second upper steel bar (110) and a second lower steel bar (210).</p> |
