| 摘要 |
The tubular construction, particularly under backfill, comprises an assembly of prefabricated reinforced concrete elements, the upper part of which is made up of an arch (2) and the lower part of which is made up of a raft (slab) (4). In order to determine the shape of the tubular construction which extends between a predetermined lower level (NO) and a predetermined upper level (NS) and which surrounds a predetermined template (ABCD), pressure is calculated as a function of level taking account of the weight of the backfill and of the overloads which may be exerted on the construction, an arch level (N1) substantially corresponding to the optimum value for which the calculated pressure is minimal is selected, at least a part of the transverse profile of the extrados of the arch (2) is given a circular arc-shape (20) tangential to the arch level (N1) and extending beyond vertical lines (L) passing through the lateral ends of the template (ABCD), and the transverse profile of the construction is completed by means of lateral walls extending between the said circular arch (20) and the raft (4). <IMAGE>
|
